Monthly Archives: December 2010

Now that the wintery weather is behind us, it’s time to get outside. And like many Canadians this summer, you’ll probably be soaking in the sun on your patio in the city or at the cottage. So why not make your time outdoors even more enjoyable with some tunes?

Listening to music outside can be as simple as using a boombox or an iPod speaker system. But if you prefer a higher quality of sound, you’ll want to install some good quality outdoor speakers. Not only will you be rewarded with a better sound, you also won’t have to bring equipment in and out of the house.

When done properly an outdoor speaker setup can be tastefully attractive and sound very good. Done poorly, it can sound tinny, muddy, and look tacky.

The Sonic Challenge of Outdoors

Any musician who has ever played an outside show knows one thing for sure: outside sucks up volume like nothing else. You’re not in your living room anymore, Dorothy, so don’t expect sound to bounce off walls and come rocketing back at you. It’s going to go out and not come back.

Acoustic technology has come a long way, but all things being equal, small speakers generally will not sound as good as a larger set that can move more air. Now before you set your flamethrower on “disintegrate”, I said, “generally”. There are always exceptions that make a rule, and indoors there are small speaker cabinets that completely blow away larger ones. However, small, unobtrusive speakers mounted outside don’t really stand a chance. Try to maximize bass response with strategic speaker placement.

Choosing Outdoor Speakers

Outdoor speakers are available in all sorts of shapes and sizes. The most common type is a bookshelf-style speaker, designed to be wall mounted. But if you’d like to conceal the speakers in your garden you may want to consider a “camouflage” speaker that has a cylinder shape, a rock shape or is built into a flowerpot. I’ve even seen frog-shaped outdoor speakers. Wireless outdoor speakers also exist. They are labeled as “wireless” because they don’t require you to run a speaker wire from the audio source to the speakers. However they do require power, which is usually provided by a rechargeable battery. A wireless outdoor speaker is nice in theory but not very practical for most applications.

Regardless of what shape or type of speaker you decide to go with, all outdoor speakers share one thing in common – they are all weather resistant and usually designed for both cold and warm climates. This means that you can leave them outdoors all year round. Although in order to prolong their life, it’s a good idea to bring them indoors during the winter.

Outdoor speaker enclosures are usually made out of a composite plastic-like material or powder-coated metal. Better quality enclosures are not only weather resistant, they are also UV resistant which means that the finish and colour of the enclosure should not be damaged by the sun. All bookshelf-style outdoor speakers are supplied with wall mounting brackets which allow the speakers to be aimed toward the listening position.

Most well-known speaker manufacturers offer a few bookshelf-style outdoor speaker models. These include brands such as Axiom Audio, Paradigm, JBL, Infinity, Klipsch, Polk Audio, Yamaha and Bose, just to mention a few. For a full list, check out the info box at the end of this article. Prices for these speakers start at about $150 and can reach all the way to several hundred dollars.

“Camouflage” speakers offer the advantage of blending in with the décor of your patio or the garden and come in various shapes, sizes and colours. The perimeter of a swimming pool is another great spot for these types of outdoor speakers.

One of the better known companies in this product category is SpeakerCraft. In addition to its bookshelf-style speakers, the company offers a number of rock-shaped speakers including three models with 5, 6 and 8-inch woofers (and 1/2-inch tweeter), a dual tweeter model and even a powered 8-inch subwoofer. All of these speakers have a realistic rock look and lack any noticeable grill holes.

TIC Corporation offers many various shapes of rock speakers in a number of different colours. The company’s Omni series consists of green cylinder-shaped speakers which project sound 360 degrees outside the enclosure. All models combine a woofer and a tweeter, while some models also have LED lights built-in which provide a gentle 360 degree light. A matching powered 8-inch subwoofer is also available. TIC also offers a pair of wireless rock speakers, powered by batteries, which come with a remote control.

StereoStone offers an impressively large selection of rock speakers and subwoofers in various shapes, sizes and colours. In addition to the rock designs StereoStone also makes a round planter speaker (which disperses sound in a 360 degree field), a rectangular planter speaker and two models of fountain speakers. To fill in the bottom frequencies the company offers a number of rock shaped subwoofers as well as subwoofers in the shapes of a planter and a tree stump. And to top it all off, StereoStone offers a selection of stereo rock speakers, which have dual woofers, designed to reproduce a wide stereo sound field.

If you have a swimming pool in your backyard and want the ultimate sound experience while swimming, you may want to consider an underwater speaker. A quick search on Google will lead you to a number of manufacturers.

Connecting Outdoor Speakers

The wire you choose should be appropriate for the purpose. It should be tough enough for external use, smooth enough to be pulled through walls, and capable of delivering a quality signal. Avoid bare wire connections when possible. Use proper connectors, like pins, plugs, or spades.

Assuming that your amplifier and source are indoors, run speaker wires to the outside through walls, not through doors and windows. It looks neater, and avoids the possibility of breakage from being constantly crimped in a door. The point where the wire exits the house should be as close as possible to the speaker location. Measure the distances you need for speaker cables a few times, and add at least five feet more. You can always cut off the excess, but a splice in a wire cut too short can reduce sound quality. Use the smallest drill bit you can get away with that still allows a wire to be pulled through easily. Use outdoor silicone sealant to fill the holes after the wire has been pulled through.

When using rock speakers placed in the garden, it is best to run the speaker wires underground. To do this, dig a narrow 12-inch deep trench and place the wires inside a plastic PVC pipe. This will prevent critters from biting through the wires and damage from a garden shovel.

Mounting and Positioning Outdoor Speakers

Bookshelf-type outdoor speakers come supplied with wall mounting brackets. Good quality brackets should have a solid feel and allow the speaker to be tilted in any desired direction. Use proper wood or masonry screws when attaching to brackets to a wall. If mounting into siding, be it wood, vinyl, or aluminum, make sure to use screws that are long enough to grab into the wood behind the siding.

The same goes for mounting on sofitt and fascia. It would be very embarrassing and expensive if your outdoor home improvement pulled down some of your house covering. And good siding installers are tough to find during the summer when they’re busiest.

Take advantage of walls and corners to boost bass frequencies. Generally, the higher the speakers are positioned, the further sound will travel out of them. Mounting the speakers under a roof or an awning will extend their life, as it will provide them protection from direct exposure to both rain and sun.

Powering and Controlling Outdoor Speakers

Most outdoor speakers are passive (non amplified) and hence you will need an amplifier to power them. The two most popular ways to power outdoor speakers are to use a separate integrated amplifier or the second zone output of an AV receiver. Many modern receivers offer a powered second zone output. Less expensive AV receivers offer a non-powered second zone output in which case you’ll have to hook up an additional amplifier. Using the second zone output of an AV receiver means that you can enjoy one source on your outdoor speakers (say a CD player) while someone indoors is listening to the radio or even watching a movie with surround sound.

If you’d like to have the ability to control the volume level and change music sources while outdoors, you’ll have to install an infra red (IR) repeater outside. Most AV receivers which offer a second zone output also come supplied with a second zone IR remote. A pricier solution is to use a radio frequency (RF) remote which doesn’t require an IR repeater. Keep in mind that since IR technology uses light, IR doesn’t may not work all that well in sunlight.

If you want to add sophistication and flexibility to your outdoor system, consider installing volume/source selection keypads. Of course taking this route adds cost to the system and means that you’ll have to run additional cables to the keypads (which usually use the same type of cable as computer networks).

Don’t rush with the installation of outdoor speakers and associated components. Plan your outdoor listening space properly. Consider where you spend most of your time on the deck or in the garden and position the speakers accordingly. Ask yourself where it would be most convenient to point the remote when adjusting the volume or changing sources. A well planned system will be a pleasure to use and provide you with hours of music enjoyment outdoors.

If you’re not comfortable with planning and installing an outdoor music system by yourself, consider hiring a qualified audio installer – most audio video stores offer such a service.

Links to Outdoor Speaker Manufacturers

Athena Technologies
Audiovox (Acoustic Research, Jensen)
Axiom Audio
Bose
Boston Acoustics
Energy Loudspeakers
Infinity
Jamo
JBL
KLH Audio Systems
Klipsch
Mirage
Monitor Audio
NHT Loudspeakers
Niles Audio
OWI Inc.
Paradigm
Phase Technology
Polk Audio
Rockustics
Sonance
SpeakerCraft
The Speaker Company
Stereostone
Tannoy
TruAudio Architectural Loudspeakers
Wharfedale
Yamaha

CES 2010 - Image - VIERA CAST Skype Screen 1 (Custom)Every year, while New Years resolutions are still being attempted and you’ve finally read through the manual and figured out how to use all the functions on your new electronics, along comes the Consumer Electronics Show to make everything look obsolete (again). CES, held in Las Vegas, the convention capital of the world, is the venue where the latest technology, gadgets and electronics make their debut to North America, and often, the world. It’s the equivalent to the Detroit/Frankfurt auto shows but for electronics. To put in perspective how important CES is to manufacturers, Sony and Vizio introduced thirty-eight new TVs while LG introduced thirty-nine. In a move that should be matched by other manufacturers, Vizio’s entire 2010 lineup has abandoned CCFL and is entirely LED backlit.

Without a doubt, the centrepiece of this year’s CES was 3D. Manufacturer including Panasonic, Samsung, LG, Toshiba and Vizio were all showing off their latest 3D-capable HDTVs. While 3D has existed for years, the phenomenon has recently been thrust back into the spotlight with the colossal success of James Cameron’s “Avatar”, a film that still continues to sell out IMAX 3D theatres days in advance. To date, it has made over $1.3B USD and while this writer disputes its all-time rank due to a lack of inflation-adjusted numbers, it still continues to top the weekend box offices months after premiering.

3D HDTVs should slowly start making their way into consumer homes as early as the spring of 2010. Although most manufacturers didn’t release pricing information, most said that 3D HDTVs should be available for a small premium compared to traditional TVs. Panasonic should be the first out of the gate with its VT25 series of plasma TVs, which will be the successor to the company’s high-end PV10 series. Two sizes of this TV will be available – a 50-inch and a 54-inch. Each set will include one pair of 3D glasses. Panasonic calls its system “Full HD 3D” since each eye will get the full 1080p resolution. Panasonic will also release a 3D Blu-ray player which will be required to play 3D movies. Samsung’s 3D television line-up includes the LCD LED-backlit series LED 9000, LED 8000 and LED 7000 as well as standard LCD and plasma televisions. Samsung will also be introducing a 3D Blu-ray player, the BD-C6900. LG’s LE9500 series (also called INFINIA) will introduce 47 and 55 inch 3D HDTV models. Not to be outdone, Toshiba will also be releasing the ZX900 series of high-end LCD LED-backlit 3d TVs, expected to start shipping in September of 2010. What’s surprising is that all the TVs in this series will have the Cell processor, which first appeared in the PlayStation 3, built-in. Toshiba says that this chip will enable its TVs to convert any 2D content to 3D. How well will this work? We’ll just have to wait and see. Vizio’s 47 inch XVT Pro 470SV 3D 1080p will be available this summer for $1,999 USD MSRP, a slight premium over comparable 47 inch 2D HDTVs but also coming with features such as built-in virtual surround sound.

As with many new technologies, it is arguably the content that pushes adoption. What good was your 1080p HDTV when all you were watching were upscaled DVDs? Fortunately, two announcements by two separate studios help solve the chicken/egg dilemma. First, ESPN has announced that it will start broadcasting 3D sports, starting with FIFA World Cup action in June 2010. Regular American football will follow shortly after. Second, Sony is teaming up with IMAX (a Canadian invention) and Discovery Communications, owner of channels such as Discovery Channel (Shark Week in 3D!), TLC, Animal Planet, and the Oprah Winfrey Network to bring a 24-hour dedicated 3D network in 2011.

The Blu-ray Disc Association has also finalized the Blu-ray 3D standard ensuring consumers will have a single accessible format. Sony’s first 3D home release will be “Cloudy with a Chance of Meatballs” in Q2. Disney will begin releasing 3D titles in Q4 of 2010. As with many new formats, the 3D Blu-ray standard introduces some new issues. The first issue is more technical and content-oriented: the 3D standard only supports 24 frames per second which limits high-speed cinematography (losing the extra frames of films shot in higher frame rates such as nature films). The second is similar to the introduction of Blu-ray and the subsequent obsolescence of DVD players: 3D Blu-ray discs are not required to be backwards compatible with 2D Blu-ray players (even if they have a 2D version of the film on the disc simultaneously). This should be less of an issue since a 3D-capable Blu-ray player will be required to view the 3D discs (and will support playing 2D discs). On a positive note, existing PlayStation 3s will be firmware upgradeable to support Blu-ray 3D. Similarly, existing Mitsubishi laser projection HDTVs are already 3D-capable and only require Mitsubishi’s yet-to-be-priced-but-apparently-”affordable” 3DC-1000 adapter to convert 3D material into a compatible format for processing by the display.

On the media server front, Moore’s Law is creating new graphics technologies that are allowing set-top devices, even those powered by measly Intel Atom processors, to deliver full 1080p video. A slew of network-capable media devices mean media libraries can finally be centralized for easy access. In my home theatre setup, my Blu-ray, DVDs and other media are stored on a server, allowing anyone on the network to access them with full menus, surround sound and extended features. The interface is intuitive, simple, customizable and extendable. Think of Sony’s XcrossMediaBar on steroids. Boxee has partnered with D-Link and will soon be releasing an “under $200″ (USD) set-top device with HDMI and Toslink outputs (great for those with older receivers that don’t support HDMI audio). The Boxee uses an innovative double-sided RF remote with media control keys on one side and a full QWERTY keyboard on the other. Its Internet connectivity capability allows it to access social network sites, video sites, and other assorted online media like CNN, BBC and other sites with streaming video. While Netflix and Hulu are still USA-only but when they eventually arrive in Canada, they will be natively supported by Boxee too. It also plays slideshows, your music collection (in lossless, if available) and allows you to surf the Internet from the comfort of your couch. Syabas, makers of the popular Popcorn Hour also introduced the Popbox, a bay-less C-200 equivalent at lower cost. All these media servers will play all the common media formats (AVI, WMV, MKV, MOV, MP4, etc.) ensuring compatibility with all existing media. If you don’t already have some sort of home theatre PC or net-/set-top, 2010 will be the year to get one.

Continuing the connectivity angle, many new TVs are Internet-connected (through either Ethernet or built-in WiFi) with offerings from Sony, Vizio, Samsung and others capable of accessing streaming video sites and even their own application store. Your HDTV could soon be the central place for email, online news and YouTube (now in 1080p HD). Watching Internet videos with friends in a home theatre environment is much more entertaining than huddled around a PC monitor, no matter how big.

As with all technological innovations, there are always the products/prototypes/concepts that are made simply to show off the realm of possibilities – even if they’ll never make it into mass production.

If you’ve had a chance to see the 1080p 100 inch Panasonic plasma at Toronto’s Bay Bloor Radio, you’ll undoubtedly already be in awe of its size and magnitude. Panasonic kicks it up another notch with their latest display that you’ll never buy, a 152 inch quad-HD 3D-capable plasma display. That’s 4,096 x 2,160 in 3D. It’s like having your own IMAX theatre in your already very large, expensive home. Sony also had a 24.5 inch OLED TV on display. Its ultra-thin form factor and stunning colour, clarity and brightness make being patient for large-scale, mainstream OLED technology difficult. To compare, the current Sony 11 inch OLED TV still demands $1,999 CAD at SonyStyle which speaks to how difficult and expensive OLED manufacturing still remains.

Back to reality, on the gaming front, the most exciting development is from Microsoft for the Xbox 360. Project “Natal” looks poised to change the player-game interaction in video games in a revolutionary way that exceeds how even the Wii, with its motion-sensitive Wiimote and Wii Fit board, did previously. Project Natal completely removes the intimately familiar controller and replaces it with the players themselves. Full multi-player depth-aware motion capture along with multiple 3D microphones allows games to engage the players as never before. In the live demos shown, a gamer played a combination dodgeball-Brickbreaker game, utilizing their entire body to jump and dodge as well as kick and swat balls. In another demonstration, two players collaborated to draw on a virtual canvas, using their bodies to form an image. It is reminiscent of early motion capture games like the one at the Hockey Hall of Fame where the player is a goalie, blocking pucks, but worlds more advanced. The fluid, accurate motion capture of anything from just the hands on the imaginary wheel (for first-person racing games) to a player’s entire body (for perspectives such as third-person skateboarding) brings a level of interaction and engagement that will fundamentally change the way video games are developed and played. It will also get gamers, some of whom aren’t always the most health-conscious, off the couch and onto their feet. The continued success of the Wii’s controller has seen other gaming companies rush to catch up as well as other electronics manufacturers adopt it in non-gaming devices. Sony is set to release a motion controller in the fall, tentatively dubbed the “Arc” and some of LG’s latest HDTVs use a wand-like controller that allows swiping motions to change channels or make other adjustments. If you’ve ever used a Gyration In-Air device, you’ll be familiar with how intuitive and natural using a motion-capable device is – it really is like an extension of your body. It shouldn’t be long before Logitech adopts accelerometer-enabled features in their line of Harmony devices.

While we’re still years (if not decades) away from watching interactive, multi-angle holograms in our living rooms, the devices and technologies showcased at CES 2010 are extremely promising and should bring a new level of realism and connectivity to home theatres everywhere. Place- and time-shifting are becoming more mainstream and soon, you’ll be able to watch your high-def media anywhere you want: at home on a portable media player/tablet, on the road through a high-speed cellular connection or on any Internet-connected computer.

For up to date news and discussions about 3D HDTVs and players visit the CANADA HiFi forum at http://www.canadahifi.com//forum

Some of us build home theatres in order to recreate the movie theatre experience at home. Some of us do it for bragging rights. Then there are enthusiasts who constantly upgrade their components in the attempt to reach ultimate home theatre nirvana. Whichever group you fit into, chances are that in your quest for components you will come across products from Paradigm Electronics and sister company Anthem Electronics. That’s because both brands have long been considered to be among the most reputable audio video brands – and not just in Canada, but around the world. Some of this success can be attributed to the fact that both brands have been around since the dawn of the home theatre and have continued to innovate and develop products that kept up with the times. Another part of this success stems from the fact that Paradigm manufacturers almost all the components required to build its speakers and audio video components – from crossovers right down to individual parts of a speaker driver such as cones and baskets. Of course, rave product reviews and a huge tally of awards collected over the years don’t hurt.

Speaker manufacturer Paradigm Electronics was founded in 1982 by Jerry VanderMarel and Scott Bagby in Toronto, Ontario and enjoyed a steady growth throughout the 1980s and 1990s. In 1998, the company acquired Sonic Frontiers Inc., a highly respected Ontario-based high-end audio component manufacturer of Anthem and Sonic Frontiers brands. Today Paradigm’s state of the art production facility, where most Paradigm and Anthem products are manufactured, is based in Mississauga, Ontario. This colossal facility is home to over 300 employees and occupies roughly 230,000 square feet. Paradigm also owns an Advanced Research Centre in Ottawa, Ontario which houses a team of 18 employees. Paradigm is Canada’s largest speaker manufacturer and ships its products to over 60 countries. Early in 2010, I was invited to a rare behind-the-scenes look at Paradigm’s Mississauga facility, guided by Mark Aling, Marketing Manager, and Rob Armstrong, National Sales Manager.

The Making of a Paradigm Loudspeaker

My tour began with a visit to the research and development department where naturally all new products are conceived. The team of engineers at the Mississauga facility is responsible for new speaker and crossover designs with the aid of a massive tool – also known as the anechoic chamber. The purpose of an anechoic chamber is to completely isolate all external noise and allow engineers to measure the sound of the speaker placed inside it. It is an indispensible tool in modern loudspeaker design. Paradigm’s anechoic chamber has a volume of 33,000 cubic feet with fiberglass wedges that are just over 8 feet long and glued to a concrete wall. A 6 inch air gap isolates the chamber from the rest of the facility. This anechoic chamber is basically a larger version of the one built years ago at the National Research Council (NRC) in Ottawa. Its larger size allows Paradigm to measure much lower frequencies (all the way down to 1 Hz) and with better accuracy. Two doors on opposite walls allow access into the anechoic chamber.

Outside each door is a computer workstation where measurements can be performed. Inside the chamber is a rotating speaker platform, controlled by the computers outside the room. A B&K calibrated microphone sits in the middle of the chamber at exactly three meters from the speaker platform. To evaluate a speaker’s performance, it is placed on the speaker platform inside the chamber, the doors are closed and the tests are initiated from a computer workstation. As the speaker rotates on the platform, Paradigm looks at three main windows: 0 to 15 degrees (direct, on-axis sound), 15 to 30 degrees (side wall followed by back wall reflections) and 30 to 45 degrees (first reflections). To measure a speaker, a series of test tones are played, similar to those that AV receivers produce when running an auto room calibration. The measurements are then translated into a frequency response curve on a computer screen – with the goal of achieving as flat of a frequency response as possible. The measuring software used here was custom designed by engineers at the Paradigm Advanced Research Centre in Ottawa. Aside from measuring speakers, the software also allows the engineers to design and match certain topologies of crossovers with various speaker designs. In addition to all this, the software allows Paradigm to compare its new designs with previous models as well as speakers from competitors. There’s no question that the anechoic chamber and custom software are really powerful tools and play a vital role in Paradigm’s speaker design.

If a prototype speaker design passes the anechoic chamber tests, it is put through a series of listening tests inside a double-blind screen listening room. Paradigm actually has two of these test rooms: one with metal stud construction and a drop ceiling, meant to emulate a store environment, and one constructed from wood studs and drywall to emulate a home setting. A double-blind environment means that a screen (similar to a speaker grille) is dropped in front of the speakers to take away the visual cues and prior knowledge of what you’re listening to. Both rooms are equipped to test speakers ranging from a typical bookshelf to in-walls, on-walls and ceiling designs. A speaker switch box allows for quick selection between various speakers. An SPL meter is used to match the volume of all the speakers being compared, to put them on an equal level playing ground. Paradigm also uses these listening rooms to test competitor speakers against its own. How was it determined that this was a good method for testing speakers? The basis of this test comes from the NRC study that Floyd Tool and Peter Schuck (now head engineer at Paradigm) participated in originally some years ago. The goal of this study was to develop measurable characteristics of a loudspeaker that most listeners enjoyed. The three resulting characteristics were determined to be off-axis response, flat mid-range and low distortion. This became the recipe for 95 percent of the population for what they enjoyed in a speaker.

When we stepped out on to the production floor, the scale of this manufacturing facility was put into perspective for the first time. This is a truly gigantic operation.

The production process begins with the manufacturing of the individual parts that make up a speaker. A tour of the injection molding department proved to me that Paradigm really makes their speakers completely from the ground up. The machines here are used to injection mold plastic parts such as speaker cones, surrounds, baskets, baffles, port tubes and other plastic parts that you might find in a speaker. Here’s how it works: raw plastic pellets enter the machine’s hopper and are fed through a heat chamber where they are converted to a liquid form. A network of “veins” directs the liquid plastic into a tooled-metal mold, where the part takes its shape. The tooled-metal mold of course has to come from somewhere for each part – and I was amazed to learn that Paradigm makes even these in-house, in its machine shop. To make the molds, Paradigm uses a state of the art machine that doesn’t make physical contact with the raw metal block (like other milling machines), instead the machine eats the metal away at the molecular level to create the shape of the mold. It may take several hours to produce a mold but once complete, the mold can be used to produce hundreds of thousands of the same part.

Armstrong mentioned that Paradigm is the only speaker company in the world to apply an over-mold technique in the manufacturing of some of its drivers. This technique is used to fuse together the surround to the cone. This eliminates the need for using glue and results in some of the most durable and hence reliable drivers on the market.

The other key components of a speaker driver including the voice coils and magnet structures are also built in this facility. Most of this work is done by hand, with the exception of the winding of the voice coils which is performed very accurately by a machine. Once all of the individual components are manufactured they are moved to the assembly area where the driver is assembled by hand.

By this point of the tour, I had already observed a few manufacturing techniques at work that I hadn’t seen before. And just when I thought it couldn’t get more interesting, we walked up to a 3D printer which Paradigm uses for advance prototyping. Engineers from the R&D department design three dimensional drawings and print them here in full 3D plastic composite. What’s really incredible about this printer is that it can print objects that consist of multiple parts, already assembled together. Aling showed me a few objects printed here: a fully-working set of gears, a working adjustable wrench and a hollow sphere with multiple openings which contained other spheres inside it. Printing such complex 3D objects is possible since the printer uses two different materials – one which makes up the 3D object and one which can be sprayed away after the printing is finished. This advanced prototyping technique can play a crucial role when designing new products.

After seeing the individual speaker parts being manufactured, it came as no surprise that Paradigm makes its crossover completely from scratch. The crossovers start out as an empty circuit board into which various electronic components are inserted – some by an automated machine and some by hand. The boards then pass through a machine which applies flux the bottom of the board and solders all the components. Once completed, every newly built crossover is tested against a reference crossover to ensure proper operation, before it is mounted into a speaker cabinet.

Amplifier boards for some of Paradigm’s latest subwoofer use tiny surface-mount electronic components for the most part and hence are built by a fully automated process. Here’s how this works: a large reel containing all the electronic components in a predetermined order is fed into a machine which removes each component and inserts it into the circuit board. The machine performs tens of insertions per minute with perfect accuracy. The electronic components come in a reel (automatically assembled by a separate machine). You guessed – even these reels are made right at this facility.

The final piece of the puzzle – the making of the speaker cabinet – takes up perhaps the largest amount of the production floor space. Stacks of giant wood boards come with the vinyl already laminated on it from a wood supplier just down the street from the Paradigm facility. The boards are first cut into small pieces called “sleeves” by a fully automated table saw. The size of the sleeves is determined by which speaker model is being manufactured. These smaller boards are then sent to a router, where various cuts and grooves are made. To complete the job, a machine applies glue and folds the cabinets giving them the finished shape.

Of course, it’s not a speaker until all of the components are assembled together. During the last stop of the production process, the baffles, drivers, tweeters, crossovers and dampening materials are assembled into the speaker cabinet. The speakers go through a final quality inspection and are then packaged.

The Making of an Anthem Component

As mentioned previously, all new speaker designs are handled by engineers at the Mississauga office. The Advanced Research Centre in Ottawa on the other hand is responsible for amplifier designs, audio and video circuit boards and programming code for subwoofer DSP processors. The Ottawa team also wrote the software for anechoic chamber testing and develops on-going software updates. Aling joked that the engineers at this location are constantly engaged in improving amplifier designs which results in a challenge for the speaker designers since they have to come up with designs that keep up with the new amplifier designs. Call it a healthy camaraderie between the offices, which results in some pretty outrageous designs. Take the new SUB 2 subwoofer for example – it has a 9000 watt amplifier and no less than six active drivers. To put this into perspective, in order to get maximum output from this subwoofer, you’ll need to connect it to a 240 volt outlet! Overkill for most? Yes. But the lessons learned from such designs trickle down into much smaller and more affordable subwoofer models that a much larger audience can enjoy.

The assembly of circuit boards for Anthem components takes place at the Mississauga facility. Since the surface-mount electronic components are very small, the insertion and soldering of these components is completely automated. As for the subwoofer circuit boards, the electronic components come from a pre-assembled reel. Again only some of the larger components are inserted by hand. The face plates for the components are cut very precisely by the same machine which makes the metal molds for injection molding. Once the circuit boards are assembled into the chassis (also made in-house), the various inputs/outputs of the boards are connected to a test jig which checks every function of the boards. When everything passes this stage, the component is moved to a burn-in rack where it sits plugged in overnight. The next morning the component is tested for the second time and then taken to a “UPS simulator” which is basically a shaking table. The component is then tested one last time and if it passes here, it goes off to packaging.

Final Thoughts

It is truly refreshing to see a giant like Paradigm thriving in Canada during a time when most audio video products are manufactured overseas. All Anthem components and nearly 90 percent of Paradigm speakers are manufactured locally at this facility. The remaining 10 percent that are made overseas include entry-level in-wall speakers, Cinema speaker packages and cabinets for the Studio and Signature speakers.

Having everything under one roof allows Paradigm to maintain a very high level of quality control and come to market with new products much quicker than other manufacturers. Although Aling joking noted that “Paradigm’s engineering is so state-of-the-art that often times we can’t come to market with products as quickly as the marketing department would like.” I personally don’t mind. Knowing that some of the top speakers and home theatre components are produced in our neck of the woods makes me extremely proud.

Click here to discuss this article on the CANADA HiFi Forum

Manufacturer Info:

Paradigm Electronics Inc.
www.paradigm.ca
Anthem Electronics
www.anthemav.com
Tel: (905) 564 – 1994

So you read the Toronto HiFi magazine and from time to time you come across a term which you don’t have a clear understanding of. Perhaps you don’t understand it at all. Chances are, you’re not the only one. When it comes to HiFi and Home Theater equipment, we talk about very specific things that you won’t read about just anywhere. And they certainly won’t come up at the dinner table. This article, or more appropriately glossary, is the first in a series that will help you understand what all the different Home Theater terms mean. Below you’ll find much of the terminology that we frequently use when we talk about speakers. Once this issue disappears from the stores, you can continue using this glossary as a reference from the Toronto HiFi website. We’ve arranged the list in such a way that reads easily, with related terms collected together.

Understanding Speaker Specs

The frequencies within the range of human hearing are 20 Hz – 20 kHz.

Decibel (dB) – One-tenth of a Bel. Named in part after Alexander Graham Bell (hence the capital B), the decibel is used in both audio and video applications (although more often the latter) to compare power differences in voltage, current, watts, sound pressure levels (SPL), etc. The number of Bels is the common logarithm of the ratio of two powers. If two powers differ by 1 Bel, the greater one will be 10 times the other. A 100-watt amplifier is 1 Bel, or 10 dB, higher in output than a 10-watt unit. Decibels are ratios, not fixed quantities. The logarithmic nature of the decibel scale corresponds to the logarithmic nature of human hearing. One dB SPL is commonly accepted as the smallest difference that people can hear, depending on the bandwidth of the manipulated signal. When measuring audio signal-to-noise ratios, the difference between the quietest and loudest sounds is stated in dB.

Efficiency Rating – The loudspeaker parameter that shows the level of sound output when measured at a prescribed distance with a standard amount of energy fed into the speaker. Efficiency rating standard is 1 watt at 1 meter and is measured in decibels.

Frequency Response – Refers to what frequencies can be reproduced and how accurately they are reproduced.

20 Hz – 40 Hz – Low Bass
40 Hz – 80 Hz – Mid Bass
80 Hz -160 Hz – Upper Bass
160 Hz – 320 Hz – Lower Midrange
320 Hz – 640 Hz – Midrange
640 Hz – 1.28 kHz – Upper Midrange
1.28 kHz – 2.56 kHz – Lower Treble
2.56 kHz – 5.12 kHz – Mid Treble
5.12 kHz – 10.2 kHz – Upper Treble
10.2 kHz – 20.4 kHz – Top Octave

Impedance – Impedance ratings are included to offer an idea of how difficult a load the speakers are as far as the amp is concerned. Plugging a 4 ohm speaker into an amp rated at 8 ohms and above will damage the speaker and/or amp at louder levels, as it cannot handle the current demands of the lower impedance speaker. That being said, some ampsare perfectly capable of driving a 4 ohm speaker and will infact sound better when driving lower impedance speakers.

Input Impedance – The “load” actually seen by a source connected to an input. In audio, the input impedance should be considerably larger than the connected component’s output impedance to avoid signal losses and frequency-response irregularities. In video, the input and output impedance should nearly match.

Magnetic Shielding – Magnetically shielded speakers are important in Home Theater applications because of the damage the magnetic field of a speaker can do to a television set. This feature is critical for the centre channel and front left/right speakers.

Output Impedance – The impedance seen by an electrical load attached to the output terminals of an audio or video device. For practical purposes, the output impedance of any audio amplifying equipment should be low in comparison to what it is connected to. It should not only be low at low frequencies, where it will affect bass damping, but should also be low at higher frequencies to insure a flat frequency response. In video systems, output and input impedances should closely match.

Ohm – A measure of how much something resists (impedes) the flow of electricity.

Sensitivity/Efficiency Rating – The loudspeaker parameter that shows the level of sound output when measured at a prescribed distance with a standard amount of energy fed into the speaker. Efficiency rating standard is 1 watt at 1 meter and is measured in decibels. Efficiency rating dictates how loud a speaker will play for a given amount of power.

SPL – Sound-pressure level, measured in dB. More equals louder.

Watt – A unit of power or energy. One horsepower is equal to 745.7 watts. Amplifiers do not deliver watts (they deliver voltage), nor do speakers create them. When presented to a specific load (speaker impedance), current flows and the power dissipated is rated in watts. Wattage produced may be calculated by multiplying voltage times current or by squaring the voltage and dividing it by the impedance.

Speaker Components/Crossovers

Active Crossover – A powered electronic network that divides up the frequency constituents of an audio signal (bass, midrange, and treble) before it is amplified and sent to the various drivers in a speaker system. While active crossovers are often contained within subwoofer enclosures along with the bass driver(s), those that work with multi-way systems may also be outboard mounted.

Binding Post – The termination point of an amplifier or loudspeaker where the speaker cable is connected.

Crossover – A component that divides an audio signal into two or more parts by frequency, sending, for example, low frequencies to one output and high frequencies to another. Crossovers are sometimes built into amplifiers or equalizers.

Damping Material – Any material added to the interior of a speaker enclosure to absorb unwanted sound and reduce the out-of-phase reflection to the driver diaphragm.

Diaphragm – The part of a dynamic loudspeaker, attached to the voice coil, that produces sound. It usually has the shape of a cone or dome.

Ferro Fluid- This substance is a magnetically attracted liquid that works well at cooling tweeter and midrange driver voice coils. This is because it stays suspended in the magnetic gaps between the coil and the heavy magnet assembly, conducting heat to the latter. It also can affect speaker damping. In some tweeter designs, silicone grease will work better than Ferro fluid.

LFE (Low Frequency Effects) – LFE refers to bass. You really need a powered subwoofer to truly enjoy the LFEs on many Dolby Digital and DTS DVDS. The signal generally ranges between 20-150Hz.

Passive Crossover – A non-powered electrical network that divides the frequency constituents of an audio signal (bass, midrange, and treble) after it has been amplified and then routes them to the various drivers in a speaker system. In most situations, it is enclosed within the same box as the speaker drivers.

Tweeter – A speaker designed to reproduce the high or treble range of the sound spectrum. Usually made of a rigid material (although there are soft dome tweeters).

Woofer – The individual speaker unit (driver) designed to handle the midrange and low frequency bass range. Some speaker enclosures contain multiple woofer drivers to increase bass power. The cones can be made of paper, plastic, kevlar, carbon fibre and even aluminum.

Voice Coil – The wire coil surrounded by the magnet assembly in a moving-coil, dynamic loudspeaker. The coil is attached to a diaphragm (which may be a cone, dome, or some kind of hybrid air mover) of the driver and causes it to move when excited by a signal from an amplifier. Most voice coils are made from copper wire, although a few are made of aluminum wire.

Amplifiers/Enclosures

AMP – Ampere. A measurement of electrical current. This term is also sometimes used as an abbreviation for amplifier.

Amplifier – A component that increases the level of an audio signal from line level to speaker level.

Band-Pass Enclosure – Type of enclosure used for subwoofers where the driver is completely inside the enclosure and all of the output emerges through a port(s). This configuration is usually designed for high output volume with importance of accuracy/fidelity being less emphasized.

Bass Reflex – A speaker-box design that makes use of a port or drone cone. According to parameters outlined by Thiele and Small more than twenty years ago, allows the rear radiation of a woofer cone to reinforce the output of the front, extending and smoothing low-range response. At frequencies below the reinforcement range, there will be a sharp cutoff as the port signal goes back out of phase with the front.

Biamping – Using separate amplifiers to power the crossover-separated drivers in a speaker system. When a powered subwoofer is added to a system, the latter automatically becomes biamped, with the satellites separately amplified from the subwoofer. With the right speakers, biamping can boost the output capabilities of a sound system considerably.

Bi-Wiring – Of or referring to a method of connecting the amplifier or receiver to the speaker in which separate wiring is run to the woofer and the tweeter, or in a three-way system, to the midrange driver.

MOSFET – Metal-Oxide-Semiconductor-Field-Effect Transistor. A special, high-peak-current output transistor used in some power amplifiers.

Speaker Channels

A channel is a seperate signal path. A 5.1 channel system means that it has 5 speakers (2 front, 1 center, 2 surround) plus a subwoofer.

Center Channel – The channel in a surround sound setup that is directly in front of the viewer. The center channel speaker “anchors” sound that should be coming from the front of the screen. Most dialogue in DVD movies is played through the center channel.

Front Speakers – speakers used for reproduction of majority of the sound in a home theater. The only speakers used in a stereo setup.

Rear Speakers – Used in 6.1 or 7.1 systems, where two additonal speakers are placed behind the listening position.

Subwoofer – A speaker driver designed to reproduce very low frequencies, usually those under about 100 Hz. Often larger than 6.5 inches in diameter.

Surround Speakers – The usually small speakers that are placed toward the sides or toward the rear in a surround-sound system and handle the decoded, extracted, or synthesized ambience signals.

Speaker Types

Bipole Speaker – Bipole speakers generally (there are always exceptions) use identical complements of speaker drivers located in the classic front of the box position as well as on the rear panel. The drivers are wired “in phase”. This means that since the drivers are fed the same signal, they are all doing essentially the same thing. Looking at the behavior of the woofers for example, when they are fed the positive portion of the signal (which moves them forward), both woofers are moving forward at the same time. The same goes with the midranges and tweeters. Since the drivers are back to back with each other, their relative movements actually have them moving in opposite directions. Even though the phase is the same, one woofer is pushing to the front, while the other woofer is pushing toward the rear. Theoretically, a bipolar speaker approaches a 360° soundfield – it radiates sound all around the room. That’s a good thing if you need to position your surround speakers behind your listening position. Some people prefer the greater localization of bipolar speakers when used in digital discrete (Dolby Digital 5.1, DTS) systems (see Figure 1 at top of page).

Dipole Speakers (and how they are different from Bipole Speakers) – Dipoles radiate sound from the front and back. In contrast to bipoles, the sound is propagated out of phase. The result is that there is a “null” or a dead zone of sound in the area along the 90 degree axis of the speaker (see Figure 2 at top of page). When properly set up, a pair of dipole speakers used as surround speakers will provide a very open, enveloping rear effects soundstage without allowing you to pinpoint the location of the speakers themselves. But for all this to work properly, the speakers need to be positioned “in-line” with the listening position as shown on the illustration below. If you are sitting out of the null area, the effect is ruined.

Monopole Speaker – A monopole speaker is the “classic” speaker design familiar to most people. The monopole is a box speaker with its complement of speaker drivers (most often cones and domes) usually located grouped together on one side (the face) of the box. Sound propagation is achieved as all drivers operate by moving air in the same direction.

Three-Way Speaker – A loudspeaker system that uses separate drivers for the high frequencies, midrange, and bass. Certain designs may have more than three speaker drivers, but because some are paired together to handle the same frequencies, they will still be three-way designs.

Two-Way Speaker – A speaker system that uses separate drivers for the high and low frequencies; the midrange frequencies are split between them. Two-way systems usually suffer from midrange dispersion problems, because the woofer, which must be robust enough to do decent work down low, is usually not small enough in diameter.

Speaker Wire/Connectors

Guage (speaker wire guage) – The thickness of a wire’s conductive copper bundle. The lower the gauge, the thicker the wire, and the better its capacity to pass the amplified audio signal. Speaker wires available on the market range from 12 to 16 guage. Thicker wires generally deliver cleaner sound and are a must for longer wire runs.

Bare wire – generally used to connect less expensive speakers and receivers. The wire sheilding is stripped away and inserted into a spring clip. It can also be used with a binding post.

Pin plug – thin, metal rods pushed into a binding post or spring connector. They provide the least surface area of all connection types.

Spade lug – flat, U-shaped pieces that fit around the bolt-like metal post in a binding post. Provides the most surface contact (along with the Banana plug).

Banana plug – made up of “wire strips” that compress as the banana plug is inserted into the binding post and then expand again inside the post to hold the banana plug inside. Provides the most surface contact (along with the Spade lug).

Suave’s Picks Neil’s Picks
Star Trek DVD/Blu-ray, $24 and up Caig Laboratories DeoxIT Gold Contact Enhancer (G5MS-15, $9.95 US) and Contact Cleaner (D100S-2, $19.95 US)
This holiday season, the Enterprise will set course for millions of home theatres across the planet. JJ Abrams’ Star Trek, released in movie theatres earlier this year, pleased not only long-time fans of the franchise but masses of other movie goers. It’s safe to say that this movie will become one of the top demos for showing off a home theatre’s capabilities. Look for four exclusive editions that come with: o-sleeve package, a steelbook case, packaging that assembles to become the U.S.S. Enterprise disc storage or 4 replica Starfleet division badges. www.paramount.com These are some of the best cleaning and contact enhancing products available today, used and endorsed by Boeing, Xerox and db Sound among many others. The Cleaner eliminates oxidization and atmospheric contaminants and the Enhancer improves conductivity and protects metal surfaces. Use on RCA connectors, RCA input/output jacks, speaker cable connectors and binding posts, etc. Highly recommended! www.caig.com
Furutech FP-204(R) Banana Plugs, $25.99 each Clearaudio Clever Clamp, $28
To an audio video enthusiast, getting accessories is like getting jewelry. These Rhodium-plated banana plugs use Furutech’s exclusive a-Alpha Process and are the best plugs I have found to date to put on speaker wires. Each plug holds the wire very securely with not one but two screws. Once the plug is inserted into a speaker terminal, a few twists of the knob secures the plug in place. We use them on all of the speaker cables in our lab! www.furutech.com The Clever Clamp provides a simple, yet effective tool to ensure vinyl LPs are clamped to the platter. As a result, it reduces potential slippage and deleterious effects of warpage such as wow and flutter. Simply place on top of the record and you’re ready to go. The Clever Clamp is also easy to remove thanks to its upturned edges. Make that special someone realize improved dynamics and bass response when listening to their valuable vinyl collection! www.clearaudio.de
Spears & Munsil High Definition Benchmark Blu-ray, $25 US IsoTek Full System Enhancer CD, $32.99 US
Far too many TVs produce a mediocre picture out of the box. To unlock their full potential, you will need a calibration disc such as this one from Spears & Munsil. Unlike other calibration discs which are confusing to use and come with little instruction, this disc should be simple enough for just about anyone to use and comes with detailed instructions. www.spearsandmunsil.com This CD provides a set of sonic algorithms to burn-in new equipment and cables and eliminate magnetic build up in your existing AV system. The disc has three tracks: the first track is designed for bookshelf speaker systems with limited bass response, the second track is designed for full range systems and the third track is a refresher. Reduces burn-in time dramatically and effectively eliminates magnetic build up throughout the system including the drivers in the speakers. www.isoteksystems.com
Sonic Fabric Necktie, $90 US Transformers Gift Set Blu-ray, $54.99
Wearing a Walkman around their neck isn’t likely to attract any ladies. But here’s something that just might do the trick! These ties are made from 50% recorded audio cassette tape and 50% coloured thread. And believe it or not, if you run a tape head over the tie, you can actually hear the sound of the tape. Available in three colours: dark brown, light gray and black. Search for “sonic fabric” at www.supermarkethq.com The Transformers movies represent pure unadulterated fun while showcasing the benefits of the Blu-ray format. Outstanding film transfers with uncompromised detail and colour combined with phenomenal Dolby TrueHD soundtracks provide a real test for any home theatre system. Both movies packaged together at a great price make for a wonderful stocking stuffer! www.paramount.com

You’ve probably encountered the phrase ’3:2 pulldown’ in a description of an audio video product. DVD players perform it, projectors perform it and even televisions perform it. So what exactly is 3:2 pulldown?

To fully understand what 3:2 pulldown is, we first have to understand why we need it.

Movies are shot using 35 mm or 70 mm film. The film is a series of still pictures called frames. When these frames are projected at a rate of 24 frames per second at the theatre, you get a moving picture. A movie!

Most of us aren’t George Lucas or Steven Spielberg so we don’t have a film projector and a theatre at home. We use televisions, be it plasma, LCD, or CRT. Even those of us who do have a projector at home, certainly aren’t feeding it film. What our home displays and projectors are expecting through their inputs is NTSC video.

NTSC video is displayed at 30 frames per second. Each frame is made up of 525 horizontal scan lines. In our wonderful DVD format, 480 of those scan lines are available to contain picture information. NTSC video is interlaced. In other words, even though the video is shown at 30 frames per second, only half of these scan lines are displayed at a time, creating two video fields per frame. The first video field is composed of all the odd horizontal scan lines and the second is composed of all the even horizontal scan lines. To complicate things further, when you put these video fields together they don’t give you a picture like the frames did in film. Each video field represents a moment in time, 1/60th of a second. If the video is of a still object and the camera is not moving there is no problem, you interlace two fields together and get a crisp picture. But, as soon as the object or the camera moves, putting two fields together creates distracting interlace artifacts on the display.

So to reiterate, film is made up of 24 frames per second and video is made up of 30 frames (or 60 video fields) per second. Simply transferring film to video would result in the film being displayed 25% faster than intended. Instead of 24 frames being displayed per second, 30 frames would be displayed. The solution is the ‘telecine machine’ used to transfer film to NTSC video which performs the 3:2 pulldown process. The 3:2 pulldown process uses a mathematical approach of repeating film frames to prevent the speedup of the film when shown on your television screen. Simply put, it converts 24 frames of film to 60 video fields by repeating the film frames in a 3-2 pattern.

For example: 4 film frames ABCD would each be divided into 2 interlaced video fields. So we get A1A2, B1B2, C1C2, D1D2. These fields are then repeated as A1-A2, A1-B2, B1-C2, C1-C2, D1-D2 (see figure 1). Notice the 3-2 cadence. If we repeat this 6 times, we get 30 frames of video from 24 frames of film.

So the 3:2 pulldown process works by restoring proper timing by generating redundant image information from four film frames to construct five NTSC video frames (as in figure 1). If we were to store five frames instead of four on a DVD, we would be wasting 20% of the storage space. Fortunately the MPEG-2 standard (in which all DVDs are encoded) addresses this issue. When a film is encoded in the MPEG-2 standard on a DVD, it is stored at 24 frames per second in the interlaced format. Each video frame contains exactly the same information as the original film frame. There is no redundancy. Each frame on a DVD is written as a 720 pixel wide by 480 pixel high interlaced frame (where each frame contains two 720 by 240 fields). A DVD encoded from film contains a special 3:2 pulldown flag within the MPEG-2 data stream that instructs the DVD player to repeat certain fields to construct an interlaced picture at 30 frames per second. This process is performed by DVD players in real-time (as they are reading the DVD).

As peachy as everything seems, it’s not. That’s because the scan lines from field B2 will be displayed right after the scan lines from field A1. This can lead to some serious visual distortions.

But many of today’s displays are capable of displaying a progressive picture which is much simpler to construct from a DVD that was encoded from film. Progressive scan ‘de-interlaces’ the video fields and weaves them together to assemble a full frame much like the original film frame. But now we run into the ’24 frames into 60 fields’ problem once again. To get around it this time, the DVD player triples and doubles its frame output in an AAA, BB, CCC, DD sequence. We once again we encounter the 3-2 cadence.

This leads to another problem. Frame A is displayed each time for 1/30th of a second while frame B is displayed for 1/20th of a second each time. This temporal imperfection is called ‘judder’ and could be eliminated if televisions were capable of displaying 72 frames per second. Unfortunately that would only work for film and would leave video in quite a bind.

De-interlacing video is more of a challenge than film. Each video field is a unique moment in time and unlike film, weaving 2 fields together doesn’t yield a full frame. The odd scan lines are 1/60th of a second different from the even scan lines. Different motion adaptive and compensating algorithms are needed to correct the resulting flaws in the picture.

If you don’t think that’s a problem when watching DVDs, think again. First, DVDs are designed for interlaced displays. Second, there is a lot of DVD content that originates from video, or was shot on film then edited using video (because video editing is much cheaper than film editing), or has video special effects superimposed over the film (even something as simple as subtitles or title sequences).

DVD players must know when to switch from film-mode de-interlacing to video-mode de-interlacing and back. A documentary shot in video might have a film clip in it. At this point a good DVD player will immediately switch to film mode to provide the best picture quality. Sometimes the 3-2 cadence gets interrupted and can trip up the DVD player. You may not have realized it, but your DVD player works feverishly to decode the content.

You may have DVDs at home that contain certain scenes that always display artifacts. You have probably attributed this to a bad DVD, and it probably is a poorly encoded DVD but a good DVD player will compensate for this and reduce all sorts of problems while outputting better picture quality.

In the August/September issue we provided an introduction to do-it-yourself (DIY) audio and touched upon several DIY ideas – one of them being system tweaks. In this issue we well take a closer look at some simple and common system tweaks that can be applied to your analog setup. When it comes to turntables there are several accessories and tweaks that can be applied, some of which can be inexpensive to implement and yet can provide startling improvements. Tweaks are not just for high-end systems and often it is entry and mid-level rigs that can benefit the most. Most turntable tweaks are focused around mechanical isolation, damping and vibration. A turntable wall bracket is a good example. The idea is that the turntable is placed on a wall mounted support to improve isolation from the floor and unwanted vibrations such as those produced by speakers which are coupled to the floor. Both Rega and Pro-Ject produce turntable wall-mounts and a DIY version can be as simple as brackets and shelving. Turntable isolation platforms are another example. A simple DIY mass-loaded turntable isolation platform can consist of a heavy wooden cutting board resting on split racquet balls or isolation feet like the Vibrapod Isolation Devices that you can find at an online store like partsconnexion.com. But perhaps the most common (and simple) turntable tweak is a record clamp and there are several to choose from. Like Hi-Fi audio components, record clamps can range widely in quality and price – the $30 Pro-Ject Record Clamp and the $1500 Harmonix TU-812 MKII Record Clamp are just two examples. This article will provide and overview of record clamps and instructions on how you can build a simple record clamp using a hockey puck so you can try one out for yourself at little to no cost.

A record clamp is a device used to improve the contact between the record and the turntable mat. This is typically accomplished through the use of a weight placed on the record. There are three basic types of record clamps. Threaded clamps screw onto threaded spindles and the applied force can be adjusted by tightening the clamp. Collet style clamps also allow you at adjust the applied force by pushing down on the clamp and turning a knob to grab onto the spindle. The most common type of record clamp is a round weight which slides over an unthreaded spindle. In addition to providing a better record to platter interface and reducing unwanted vibrations and resonances, record clamps can help flatten some minor warps or bowing of the record which helps maintain proper tracking. It is fairly evident that the main variable for record clamps is weight and this likely has you asking what is the optimum weight of a record clamp? The optimum weight will depend on several factors but primarily the sub-chassis of the turntable. For turntables that are spring-loaded, too much weight may interfere with the proper functioning of the springs and alter the resonance of the design. A larger weight can be used for heavier turntables, but before you reach for a heavy record clamp keep in mind that the additional weight will be transferred to the bearing which could result in increased wear on the bearing. Now I realize that does not answer the question about the optimum weight and that brings us to the first requirement for this DIY record clamp – patience. A hockey puck was chosen for a number of reasons, they are commonly available, inexpensive, easy to work with and light enough that it can likely be used with light sub-chassis turntables and not overload the bearing. Often the cost of tweaks is not measured in terms of money but rather in time invested due to many trials so patience is a must. Consider the hockey puck record clamp a starting point, one that will let you easily try out the idea for yourself at little to no cost. Should you find that the clamp provides an improvement that you would like to pursue further, let the journey begin.

A standard ice hockey puck is a hard disk made of vulcanized rubber. Hockey pucks are about 25 mm (1 inch) thick, about 76 mm (3 inches) in diameter and usually weigh between 155-170 grams (5.5 and 6 ounces). The hockey puck record clamp is ultra-simple to construct requiring just one small hole to clear the platter spindle and making the hole is the easy part. But first you must locate the centre of the hockey puck and you want to do this accurately so take your time. There are several methods that can be used to locate the center of a circle which you can research for yourself (google: “find center of a circle”). The following steps will locate the center of a circle using a right-angled object like a right-angle triangle from a geometry kit.

Step 1 Place the right-angle corner of any object at any point on the circle. Any point will do.

Step 2 Make a mark where the two sides of the right-angle cross the circle.

Step 3 Draw a line between these two marks.

Step 4 Place the right-angle corner of the object at any other point on the circle. Any point will do, but for greatest accuracy, make it about a quarter the way round the circle from the first point.

Step 5 Make a mark where the two sides of the right-angle cross the circle.

Step 6 Connect these two points with a straight line. This is the second diameter.

Step 7 Done! The point where the two diameters intersect is the center of the circle.

Once the center has been located take some time to measure and make sure that you are in the exact center of the puck. You can drill a hole using a 9/32-inch drill bit and a drill (hand or power). Drilling half-way through the puck is more than sufficient and if you prefer you can measure the length of the spindle and drill to the exact depth (for a depth guide I used masking tape on the drill bit). With this hole size, the puck should fit snugly against most unthreaded spindles but you should check the size on your turntable. If the fit it too tight, you can enlarge the hole slightly using the drill bit and your hands. Of course the above instructions can be applied to virtually any round disc or cylinder that you would like to convert into a record clamp. A note of caution, if you are using an MC cartridge, do not use ferrous metals (steel) for a record clamp.

Now for the fun part – testing out the record clamp. My turntable is a stock Rega P1 (reviewed in our February/March 2009 issue). The musical selections consisted of albums that I was very familiar with and I purposely selected some normal and heavier weight vinyl. The first album I tried with the hockey puck record clamp was an original 1979 pressing of Supertramp – Breakfast in America [A&M SP-3708]. Immediately I noticed an overall improvement with the bass response which was tighter and better defined – bass response is often the weak point of entry-level rigs. There was also an improvement to the soundstage which now seemed wider and also to the imaging which without the clamp sometimes seems out of focus. Next I moved onto to a 1993 reissue of Kraftwerk – The Man-Machine [Capitol / EMI SN-16302]. The vinyl weight of this album is not noted but I figure it is about 150-160 grams. Kraftwerk albums are typically great recordings that are clean, dynamic and with a deep bass range. There is plenty of bass on this album and like the previous album the record clamp provided an overall improvement to the bass response which was now tighter and more dynamic. I also tried the clamp with Feist – Let It Die [Polydor, 2004, 180g]. While there were improvements to the bass response, image and soundstage, the improvements were generally subtle relative to the previous albums. The greatest improvement was realized with the Supertramp album which was also the oldest, most played and lightest of the three. Overall I was rather pleased with the results of the hockey puck record clamp especially considering that all it cost was a little time. I am definitely interested in trying a collet style clamp with my P1. Your mileage will vary with a record clamp, but if you have some time to invest, give the hockey puck a try.

For more Audio DIY projects check out Giovanni’s website http://diyaudioprojects.com

room acoutics panels web

Unfortunately when home audio systems are set up, the acoustics of the listening room are rarely taken into account. Indeed, most people opt for expensive, top of the range sound systems in an attempt to reach the best-possible sound quality. But they often ignore one essential thing: the acoustics of the listening room itself. As a sound system is used in an enclosed space (the listening room), the acoustical conditions of the room will inevitably take control of the sound quality.

This first article focuses on the main acoustical problems of the listening room and on how they deteriorate the perceived sound. In upcoming issues of CANADA HiFi, each of those topics (acoustical phenomena) will be explored and accompanied with practical advice to improve the acoustical conditions of a listening room.

Acoustics: An integral part of the reproduction system
In a typically furnished, medium-sized room which is not acoustically treated, the critical distance is small – usually only about 2 meters. The ‘critical distance’, measured from the speaker, is reached when the reverberant sound level equals the direct sound level. The direct sound is the sound that comes directly from the speakers, without any reflections. So, at that distance, 50 percent of the sound is the result of the reflections on the room’s boundaries. These reflections cause various problems such as: phase, frequency response, definition, aggressive highs, blurred image and low frequencies that are resonant, have holes in them and lack tightness. Going beyond the critical distance means reducing the direct to reverberant ratio, thus the quality of the sound deteriorates even more.

In other words, the acoustical environment should be considered an integral part of the reproduction system.

Quality and price
Contrary to what one may think, acoustical improvement constitutes one of the most efficient and economical ways to enhance the performance of a sound system, since all of the various listening parameters can be improved in a very significant way. For the DIY-ers, it is possible to treat a room with affordable semi-rigid fibreglass panels. From these panels, we can build everything we need to control acoustical problems in the listening room: acoustical panels to absorb mid and high frequencies, distant absorbers to control low-mids, lower frequency absorbers that reflect high frequencies, pressure gradient traps and bass traps.

For aesthetics, the panels can be covered with sound transparent fabrics such as the Guilford of Maine FR701. For most rooms, the acoustical materials needed to treat the room will cost somewhere between $300 and $600. Of course, fees for an acoustical consultant will vary.

What are the acoustical specifications for a good listening room?
Researchers, audiophiles and sound engineers have conducted many tests to establish listening room criteria. The International Telecommunication Union, the European Broadcasting Union and the British Broadcasting Corporation publish some recommendations about this. The most important listening room criteria include: speaker positioning, room frequency response, space between axial standing waves, RT60 (reverberation time), background noise level and early reflections. See box below for details.

Recommended room specifications
• Speaker positioning: according to ITU BS-775-2 recommendation
• Room frequency response: +- 3 dB, from 250 Hz to 2 kHz (partial)
• Space between axial standing waves: > 5 Hz, < 20 Hz
• RT60: 0.3 x (V/100 m3)^1/3 +- 50 ms from 200 Hz to 4 kHz, typically 200 to 400 ms
• Background noise level : NC-15 or near 20 dBA (demanding)
• Early reflections (0 to 15 ms): -10 dB or less relative to direct sound

What are the main acoustical problems and wow do they affect the sound quality?

Reverberation (or decay rate)
Reverberation is the product of multiple closely spaced reflections on the room’s boundaries. Reverberation extends sound and causes a mask effect on the details of the audio content. Reverberation time (RT60) is defined as the time it takes for a sound to decrease by 60 dB after its emission. In an untreated room, RT60 can vary from 0.5 to 1.5 seconds depending on the frequency, while the recommended values are between 0.2 and 0.4 seconds for good listening conditions. Substantially increased definition and details are obtained when excessive reverberation is controlled.

A room’s RT60 can be calculated with the following tool (Sabine’s theory): http://www.saecollege.de/reference_material/pages/Reverberation%20Time%20Calculator.htm

Lateral reflections
Lateral reflections create phantom sources outside the speakers, enlarging the stereo image. By doing so, they also contribute to enlarging every sound element distributed between the speakers. The result is a blurred image that lacks precision.

Direct to reverberant ratio
Direct to reverberant ratio is the difference between the direct and reverberated sound levels. Obviously, a poor ratio will contribute to mask the perceived details of the sound. What’s more, the stereo image will suffer if the reverberant sound is too strong. Let’s not forget that only the direct sound delivers the information about the position of the sound elements in the image.

Early reflections
Early reflections are those which reach the listener within a delay of 15 ms relative to the direct signal. The retarded sound creates phase problems by combining with the direct sound. The result is numerous dips in the frequency response. This phenomenon is called a comb filter.

Standing waves
Standing waves (also called room modes) are low frequency resonances that take place between two parallel reflecting wall surfaces. They result from the interaction of wavelengths (?) and the distance between the surfaces. So in the low register, standing waves cause: a level boost at some frequencies, a prolonged duration of sound at those same frequencies (resonance) and some profound dips at other frequencies. The phenomenon does not present itself the same way in all the spots in the room. This is why the low frequency response varies from spot to spot in the room. Three methods are used to solve standing waves problems. These will be discussed in the next article.

Standing waves can be calculated with the following tool: http://www.bobgolds.com/Mode/RoomModes.htm

Frequency response with treated and untreated first reflectionFrequency response with treated and untreated first reflection.  The red line shows a comb filter.

A typical listening room low frequency responseA typical listening room low frequency response

Conclusion
As illustrated above, a listening room’s acoustical conditions are key contributors to the final sound quality because they affect several parameters in a very significant way. The objective here is not to have a ‘dead’ room, but a neutral room. Some people falsely believe that the listening room should have the same acoustics as a small concert hall. This is a mistake because the recordings already contain the reverberation and the acoustical ambiance of the room where the concert took place. We don’t want to change this. I’ve recorded sound reproduced in an untreated listening room in the past with the aid of very high quality microphones. Believe me, the sound signature of such a room brings nothing positive and considerably degrades the perceived content. Stay tuned for more on this topic in upcoming issues of CANADA HiFi.

For more information on this topic, search for “acoustic AND room” on these websites:
Audio Engineering Society
Acoustical Society of America

Michel Leduc is an acoustics professor (Cégep of Drummondville), researcher (Musilab, CCTT sound technologies) and acoustical consultant (Sonart Acoustique, www.sonartacoustique.com). He can be contacted by email at info@sonartacoustique.com.

When I was younger, my father always stressed to me the importance of plugging our electronics into power bars with surge protection instead of directly into the wall outlet. He said it would protect the electronics from voltage surges – anything from smaller spikes to lightning storms. I thought it was a little ridiculous. After all, how many precious pieces of electronics have you lost to a lightning storm? Then one day the unthinkable (to me) happened. One of my family’s television sets not plugged into a surge protector blew up during a lightning storm in my neighborhood. Well it didn’t actually blow up, it simply stopped working.

While this scenario is not common at all, electrical surges and spikes occur in our power lines regularly. These surges and spikes can be severe enough to damage home theater equipment (as well as other sensitive electronics) gradually or immediately. Modern power protection equipment ranges from the simple power bar with surge protection to a power center that combines surge protection, line conditioning, voltage regulation and even power backup.

As it turns out, power bars with surge protectors (also called surge suppressors) are actually a little more complicated than first meets the eye. Depending on what level of protection and features a power bar has it can cost anywhere from five dollars to several hundred dollars.

First let’s take a look at how your home theater can be affected by unclean power and what to look for when choosing power bars and power centers to protect your investment.

In a normal household and office wiring in North America, the standard voltage is 120 volts AC (Alternating Current). Power lines are inherently noisy and voltage surges and spikes are common. This increase in the electrical potential energy can be caused by lightning storms, power company load switching, short circuits, improper home wiring, blackouts as well as power-hungry household electrical devices such as refrigerators, air-conditioners and microwaves. These high-powered devices require a lot of energy to switch on and turn off components like compressors and motors. An increase of voltage which lasts for one or two nanoseconds is called a spike and one that lasts three nanoseconds or longer is called a surge. Both spikes and surges (also called transient voltages) can compromise the performance of a home theater and over time can lead to premature demise of equipment. In the worst case, these transient voltages can reach as high as 6000 volts and fry electronics instantly. Today’s electronics are much smaller and more delicate than components in older equipment and are therefore more sensitive to current increases. Modern electronic devices can literally fry from overheating if they receive more power than they are designed for. For this reason it is becoming increasingly important to protect your electronics. No power bar with surge protection can actually save the connected components from a direct lightning strike, but the chances of a direct strike are very rare. In a lightning storm you should never rely on a surge protector to save your equipment. The best protection is to unplug or turn off your power bar. A good quality power bar will not send any electricity to the devices connected to it when it’s turned off.

A standard power bar with surge protection passes the electrical current from the wall outlet to the devices plugged into the power strip. If the voltage from the outlet rises above 120 volts, the surge protector diverts the extra electricity into the outlet’s grounding wire. One critical characteristic of transient voltages is that they are very quick. A device that serves to filter out the voltage spike has to detect the spike in nanoseconds in order to be effective. Look for surge protectors with a response time of 1 nanosecond or less. In most surge protectors the component that actually diverts this extra electricity is called a metal oxide varistor (or MOV). A good power bar will usually have several MOVs. Each MOV forms a direct connection between the hot power line and the grounding line. Generally, an MOV consists of a piece of metal oxide material in the middle that is joined to the power and grounding lines by two semiconductors. These semiconductors have a variable resistance that depends on voltage. If the voltage is below a certain level, the electrons in the semiconductors flow in a way that creates a high resistance, not allowing electricity to pass from the power to the grounding line. When the voltage exceeds that level, the electrons behave differently creating a much lower resistance. This low resistance allows the MOV to conduct a lot of current to the grounding line. Unfortunately all MOVs eventually burn out. In fact, one good surge can burn out all the MOVs in your power bar. When the MOVs cease to function, the power bar simply becomes a power strip and you may not even know it. Inexpensive power bars don’t have any visible signs that the MOVs are not working. Good quality power bars have an indicator light that tells you whether the surge protection is working properly.

Power surges can also reach your home theater through the coaxial cable carrying cable television or satellite signals. A power bar in your home theater should guard your equipment against both surges in the power lines and surges in the coaxial cable. Most modern power bars offer both types of protection plus a protection for telephones lines that are also susceptible to power surges.

Power bars come in varying ranges of prices, performance and shapes. There are many different products out there from the simplest $5 power bar (or power strip more appropriately) to a several hundred dollar rack-mountable power center that looks like a home theater component. When choosing the right device to protect your home theater you’ll have to consider several specifications and features shared among protection devices.

Let’s take a look at the ratings you should look for when buying a power bar (or center) with surge protection that might also offer power line conditioning.

To make sure you’re buying a quality product, first check out its Underwriters Laboratories (UL) ratings. UL is an independent company that tests electric and electronic products for safety. Many surge protectors made prior to 1998 are potential fire hazards. The MOVs inside them can get very hot to the point of starting a fire during a large power surge. Look for a label on the product that reads “UL Listed”, not just “UL Approved” or “UL Tested”. Also make sure the product is labeled as a “transient voltage surge suppressor”. This means that it meets the criteria for UL 1449 and minimum performance standards for surge suppressors. Not all “UL Listed” power bars have surge protection.

Every surge suppressor has a clamping voltage. This is the peak voltage the suppressor will pass to the devices plugged into it, if a spike or surge occurs. Look for a suppressor with a clamping voltage of 330 volts. Also, make sure the device is equipped to absorb surges between any pair of the three wires (positive, negative and ground) in an electrical circuit. These are indicated by the symbols L-N, L-G, and N-G.

Surge protectors are marked with a Joule rating. A Joule measures how much energy the suppressor can absorb and dissipate before it fails. The higher this number – the better. Look for surge protectors with at least 600 joules or more. Many of today’s power protection devices designed for the home theater offer ratings between 1300 and 2000 joules.

Another rating to look for is the response time. This indicates the amount of time it takes for the MOVs inside the power protection device to absorb the transient voltage. As mentioned above, look for response times of 1 nanosecond or less.

Lower quality power bars with surge protection may cause as much as 20 to 30 dB of signal loss between their coaxial input and output. This can have a tremendous impact on the quality of your cable/satellite television signals. Look for power protection devices the have virtually no signal loss through their coaxial surge protection.

Intermediate power products offer power line conditioning in addition to surge protection. AC power line noise and noise generated by other electrical and electronic devices compromise the performance of home theater equipment. These disturbances can cause inferior picture quality flawed with video streaking, lower resolution and video bandwidth. From the audio perspective, power line pollution can cause dynamic distortion and loss of peak power. Power line conditioning removes this noise from the power line and maximizes the audio and video performance in the home theater.

More advanced power products also feature filters which deliver maximum current to high power components (such as amplifiers) and isolate audio equipment from video equipment. Each home theater component can add noise to the power line that can travel through your power bar or power protection device to other components plugged into it. Isolating audio and video equipment ensures that noise is not transferred between the components. Some devices even isolate analogue sources from digital sources plugged into them.

High-end power protection and conditioning products come equipped with voltage regulators or voltage stabilizers. Power coming from the wall outlet does not always measure exactly 120 volts. At peak power consumption times during the day, it probably measures closer to 115 volts whereas at night it might be closer to 125 volts. Devices with voltage regulators constantly measure the voltage on the power line. If the voltage dips below or goes over a specified range (for example between 88 volts and 130 volts) a voltage regulator will adjust the voltage to 120 volts.

Some power protection products (like APC’s S10 and S15) even have battery backup power included for times when the power goes out completely. This will allow your home theater system to run for an additional few minutes after the power outage and will shut down your entire system properly and automatically. Of course a battery backup can be purchased separately as an addition to any power protection product of your choice.

Finally, when looking for protection for your home theater, take a look at the manufacturer’s warranty as it may be a good indication of product’s quality. Usually the more the manufacturer is willing to cover the more confident they are in their product. Of course, you should never rely on getting the money for your damaged equipment – the warranty lists all kinds of conditions under which you may not qualify to get this money.

Looking at the price of a device will give you an insight into what level of protection you can get from it. As a general rule, don’t expect much protection, if any, from a power bar that costs less than $10 – most of these are simply power strips. In the $10 to $30 range you will find basic surge protection and few features. Power bars above $40 will offer better protection ratings and carry additional features. Devices that cost a few hundred dollars and more will offer line conditioning, voltage regulation and even power backup in addition to surge protection. Consider how much your home theater gear cost you and how little that $100 or $200 power protection device may be compared to the rest of the equipment. You might look at power protection equipment as in insurance policy that doesn’t carry monthly payments. If only there was something like this for cars.

Come close, I’m going to let you into the secret for keeping your vinyl collection clean. Are you ready? Don’t let them get dirty in the first place. After building a large collection of records over many years, I have seldom needed to take any drastic action to clean a dusty or dirty album, never had to remove fingerprints, rarely had to deal with warped disks.

How do you manage that? First, store your albums vertically without over-crowding or under-crowding. That means that it should be easy to insert an album into your shelves without having to apply force, and once in place each disk should lean neither left nor right.

Next, when you want to play a disk, take it out by removing the inner sleeve from the album cover, hold it horizontally in one hand and insert the other hand into the sleeve, pressing away from the vinyl until your middle finger comes to rest under the centre hole. Pull the record out with your finger on the centre hole and the thumb supporting the edge of the disk until you can free the other hand. Now you can hold the record by pressing in on the opposite edges of the disk with the fingers of both hands. At no time should your fingers or your palm touch either surface of the disk. If you can do this in your sleep, move on, but if you can’t, go find a disk you don’t care about and practice this maneuver until you have it down pat. Pretend the vinyl surface carries a 500V charge – that should motivate you. Once you can remove a record without touching the surface, you’re half way there.

Placing it on the turntable and removing it should be easy, always using the two flat hands stance. I prefer to do this with the platter not spinning, but some keep the platter spinning at all times.

As soon as you’ve finished playing a disk you should return it to its cover to prevent dust build up. To put the disk back just do the same steps you took to remove it, but in reverse. Remember to align the open edge of the liner along the upper edge of the album cover, so you get a good airtight seal.

Never lend an LP to friends or family unless they are just as fanatical as you.

Static electricity attracts dust to the record surface so you’ll want to take measures to reduce or eliminate it. Ideally you should store your collection at a moderate humidity level of around 40%, and a constant temperature of around 20 degrees Celsius in a fairly dust free room. Use an anti static gun or an anti static brush on your disk before each play, while it is sitting on the spinning platter. That’s the only cleaning I ever do or ever need to do, and I never use any fluids on my records. Reserve the record cleaning machines and fluids for records you have bought used, or records you’ve had in your collection since before you learned that prevention works better than cure.

Cleaning a stylus is a controversial matter. Some believe the chances of damaging the cantilever outweigh the benefits of removing dust from the needle. If you have used fluids on your records, or have transferred the oils from your fingers onto the grooves by incorrect handling, then this gunk will find its way onto your stylus and now you do have a problem. The oils will trap more dirt and pretty soon you’ll have no choice. So what I would do is get a high quality stylus cleaner, and apply it very gently while the arm is locked into the armrest. You should do this only when you have a problem, and you’ll need a magnifying glass to help you make that determination. For the rare occasions I need to clean my stylus, I use an ultrasonic cleaner from Audio Technica (AT-637), no longer available.

How often do you need to change the stylus? Well there’s no simple answer. The guidance used to be every 2000 or 2500 hours of use. With a high quality setup, your cartridge carefully aligned and tracking well, much longer stylus life is now common. I’ve gone over 5,000 hours without issue. You should examine your stylus under a magnifying glass or microscope every 500 hours or so to determine when it is worn, although your ears may tell you first. Any sign of distortion or loss of detail should be investigated.

You can’t simply replace the old stylus in a moving coil cartridge – it needs to be retipped, an expensive process which involves sending it back to the manufacturer or another retipping service. Expect to pay 30%-50% of the cartridge price for such a service. Given the cost, you may prefer to switch cartridge at this point. Most moving magnet cartridges on the other hand offer easy stylus replacement. The old one just slides out and a new one can be easily inserted. In some cases you can even upgrade your cartridge by installing a stylus with a more refined profile from the original manufacturer. As always when touching a cartridge, remember these things can be very delicate so treat them with the utmost care.

The biggest problem I’ve had with my turntable (a 1980 vintage Linn Sondek LP12) is how to avoid the jarring effect of footsteps on the suspension. You get this if your floorboards transmit footfalls across the room. You can minimize the problem by carefully selecting a good location in the room, taking into account which direction the floorboards run, or possibly by careful choice of platform. Sometimes the simplest solution is the best. After years of messing around, I bought a Target wall-mounted turntable support, attached it to the studs and that fixed it for good. It may be a bit ugly, but I found a solution to that too. I built a cabinet around the wall-mounted stand so cunningly designed that unless you come right up close you can’t tell the stand isn’t a part of the cabinet. There are other ways to isolate the turntable, including special stands with built in isolation, or isolation shelves like the Townsend Seismic Sink that fit between your stand and your turntable. You can also try replacement feet for your turntable – the market is overflowing with options. Some methods work well with one kind of turntable but not another, so you will need to experiment for best results. Bass sound waves can also feedback into the turntable, especially on non-suspended platters, so be careful to position your speakers well away from the turntable.

Whatever kind of stand you have it must be perfectly level and a bubble level is the only way to tell for sure. You want the long kind and you’ll need to check it front to back and side to side. Place it on the platter itself when leveling.

If your turntable has a fine adjustment for rotational speed, you can buy an inexpensive strobe to fit over the spindle, or build your own strobe here: http://www.vinylengine.com/strobe-discs.shtml. When the speed is bang on, the room light with its 50Hz frequency should cause the bars to stop rotating. Pitch accuracy is much less important to most ears than pitch stability. Unless there is something actually wrong with your turntable, pitch stability is a feature of design and build quality. Expect best results with very heavy platters, tight machine tolerances and high quality bearings.

If you have a belt drive turntable, you may need to replace the belt once every few years. It’s best to get advice from the manufacturer on this. If you see the belt slipping lower than usual on its pully or on the platter, or you hear it slip when you power up the motor, these are signs the belt has stretched or dried out and it’s time to replace it. For those of you with idler wheel drives, these can wear unevenly over time and will become noisy or lose their pitch stability. You can replace them inexpensively if parts are still available, or you can have them rebuilt. Direct drive turntables should run maintenance free. Your instruction manual will indicate how and when to oil the bearings.

A turntable must not only be set up correctly when you buy it, but may need regular tune ups to keep it well tuned. This applies far more to suspended turntables like my Linn LP12 than for a non suspended turntable like a Rega. Should you do it yourself? Almost certainly not. In most cases getting the suspension level and free floating requires considerable attention to detail, careful dressing of the leads being one particular pitfall, and is as much an art as a science. Fortunately turntable design has advanced over time so as to make these adjustments easier and less frequently required than in the past. Once again you should seek advice from the manufacturer.

Now stop obsessing and enjoy your collection.

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