Subwoofers have been around for ages and have become a common fixture in most home theatre systems but many purist two-channel audiophiles have shunned them because they have a reputation for making the overall two-channel sound woolly, turgid and boomy while degrading the focus of the sonic image and soundstage. Besides, they have hitherto been notoriously difficult to seamlessly integrate with the main speakers. Performance expectations of a sub in a two-channel system are generally exponentially higher than in a home theatre setting because in the former, your whole attention via your aural senses is on the sonic performance in contrast to the latter where your attention is divided between your visual and aural senses thus rendering the sonic performance less critical.
The bass content of music that is in many instances dominated by the kick drum, bass guitar, cello, timpani, double bass, bassoon, tuba and the lowest pipe organ and piano notes, serves to lay the foundation that underpins the music that you hear, in the same way that the foundation of a building anchors and provides stability to the building. The best full range speakers are great at laying down this foundation, but they are usually as large as small fridges, making them suitable only for large listening rooms and giving them a very low wife acceptance factor. This is what makes the option of a good subwoofer so attractive. Since the sub 80 Hz output of a subwoofer consist of relatively long sound waves it makes them non-directional, and difficult for the human ear to localize. This allows you to place the subwoofer almost anywhere in the listening room, although there are specific locations that could enhance a sub’s performance, which we will get to later.
A subwoofer offers many advantages. If it is well built, utilizes the right driver unit and is driven by a well designed amplifier with ample clean power, it relieves your main speakers and amplifier from the task of processing signals below 80 Hz which gobbles up much of a speaker’s and amplifier’s resources. Once liberated from this task, your amplifier and main speakers are free to focus on frequencies above 80 Hz, which they can then deliver with a lot more ease, accuracy and finesse.
Staying with the ‘foundation’ metaphor, it is vital for any reproduced music to have a strong bass foundation or else it will sound relatively thin and anaemic. However, as in the case of a building, it is also important for any foundation to be not just strong but also firmly and seamlessly bonded to the main structure it supports. With true full range speakers, the manufacturer can ensure seamless integration. However when you add a sub to your current two-channel speaker system, the onus on getting the sub to work seamlessly with your main speakers now falls squarely on you. And therein likes the subwoofer conundrum at the consumer level.
Outboard crossover networks that help subs work seamlessly with main speakers are few and far between so I am always delighted to find one of these rare jewels that help subwoofers dance with the main speakers, without putting a foot wrong. Moreover, I have a pair of main speakers where the woofer and tweeter work so incredibly seamlessly and deliver such an amazingly harmonious top to bottom (35Hz) continualness, it whets my appetite to find crossovers that allow me to enjoy similar harmony between a subwoofer and my main speakers.
I am glad to report that I have found another of these rare jewels: an outboard crossover network that truly satisfies. Since it is made by JL Audio, I thought it fitting that I review it with a pair of subwoofers also made by the same manufacturer. I feel flattered that JL Audio bestowed on me the honour of doing the world’s first review of their brand spanking new CR-1 crossover (expected to retail for $2,500).
My initial choice of subwoofer to review was the JL Audio Fathom f113 but Manville Smith at JL Audio suggested that I try out two of the smaller Fathom f112 instead ($3,200). He opined that the f112 would integrate better with my main speakers in a two-channel setup and deliver more even bass in the listening room. This made sense as, based on the laws of physics, the f112’s smaller cone would be faster and therefore better able to keep up with the incredibly fast 6.5 inch Scan-Speak woofers in my main speakers.
Dave Singh of Gemsen, JL Audio’s Canadian distributor, delivered the f112 subs. This was just as well because despite its compact dimensions, these subs weigh a backbreaking 115 pounds each not counting the heavy packaging. We got such a thorough workout carrying the two subs from his car to my underground listening room; we both decided to skip the gym that day.
Unpacking the f112 was made easier by the clever configuration where the subs are factory packed upside down in the carton. You therefore open the top, flip the carton and lift it off the sub rather than lift the sub out of the carton, which could be an hernia inducing act of folly, especially if you attempt it on your own. JL Audio provides a pair of white nylon knit gloves with urethane palm coat to handle the subs. They also cloak the sub in a protective soft cloth bag during shipment. Classy!
The gloss finish of the subs is as good as any I have seen in the audio world. It is also hard to miss the incredible build quality, which was very evident as Dave and I grunted and groaned while moving the subs around before placing them in their final locations.
The final locations of the subs were determined by the “crawl test” which requires you to place the sub in the listening position as close to where your ears would be when you sit in the sweet spot. You then have to run some deep, bass-heavy music as you crawl on your hands and knees around the perimeter of your listening room with a few post-it notes. You will find spots where the bass is unnaturally heavy and boomy, other spots where the bass is very thin and a few spots where the bass is just right and uniformly so. Each time you hit the latter, you place a post-it note on the floor. You can then choose from the marked locations to place your subwoofer(s). If you have a choice, place the subs in the front of the listening room.
The process of integrating a sub with your main speaker system is as important as the quality of the sub you use. This process begins with the use of a well-designed, high quality crossover. It is a pity that most subwoofer owners rely only on the low pass and perhaps a high pass filter built into the sub to divide up the frequencies between the sub and the main speakers, as these do not do the same bang-up job as a first class outboard crossover unit like the CR-1.
The first thing that struck me about the CR-1 was its size and weight. This is easily the biggest and heaviest crossover I have encountered. I guess this is in keeping with JL Audio’s penchant for bulletproof build quality. The in-depth planning that went into the CR-1 shows on the silver façade, which has a set of rotary frequency and damping knobs for the subwoofers and for the satellite/main speakers. Between those controls is a rotary control to level match the subs with the main speakers. These options offer enough control and fine-tuning while limiting the number of controls. This also cleverly minimizes the damage that overzealous neophytes can do to the signal. The rear of the CR-1 has a plethora of connection options including balanced and single ended inputs for the main stereo and managed bass signals as well as balanced, single ended and 1/4 inch TRS jacks for satellite and subwoofer outputs.
Rather than having overlapping frequencies, I prefer to have a clean cut-off point where the sub gets everything below that point and the rest is fed to the main speakers. Since I used the CR-1, for the purpose of this review all the signal processing options on the front panel of the f112 were defeated. After a lot of experimentation I set the cut-off point on the CR-1 to 50 Hz, which is its lowest cut-off frequency. A more common cut-off frequency is 80Hz, but my Merlin VSM speakers are so good at everything down to 35Hz, if the CR-1 had offered a 30Hz or 40Hz cut-off, I suspect that one of those would have delivered even better performance.
Manipulating the controls on the CR-1 while playing test tones from 20Hz to 100Hz and monitoring the subwoofers output with my trusty Pyle SPL meter, allowed me to arrive at a relatively flat response across these frequencies. I then used my ears to fine-tune the system for optimum performance. With this modus operandi I was able to get the subs to harmonize with my main speakers and my listening room so satisfactorily, I found myself gleefully dancing an impromptu happy jig.
Before I get to the sonic performance let me quickly list a few f112 specifications for technically inclined readers. The driver is a 12 inch long-throw unit (offering an amazing 3-inch excursion), backed by a 1,500 watt RMS switching amplifier encased in a sealed gloss black enclosure measuring 15 x 18.5 x 17.63 inches (WxHxD). The signal processing options include a variable low-pass filter, a variable phase control, switchable polarity, an ultra low frequency (25 Hz) trim and an Automatic Room Optimization (ARO) system. The ARO utilizes a calibrated microphone that is placed at the listening position and connected to the sub as it generates a series of test tones to create a single band equalization to help the sub adapt to the room acoustics.
A switch is provided to compare the sub’s performance with and without the ARO-created filter in the loop. The sub can be designated as a master or a slave unit and the ARO automatically calibrates the slaves when the procedure is run with the microphone connected only to the master. The power switch has three positions – on, off and auto. Phase can be adjusted from zero to 280 degrees and the polarity can be switched between zero and 180 degrees. The green light can be dimmed or switched off. Having all these controls on the front of the sub makes them easily accessible and yet hidden when you put on the grill. The rear of the unit mostly comprises a heat sink for the amplifier and offers single ended and balanced inputs, as well as a slave output to another subwoofer. The back also has master/slave and grounded/isolated switches. The anechoic frequency response is 21 Hz to 119 Hz (1.5 dB), the effective piston area is 84 square inches while the effective displacement is an impressive 287 cubic inches.
One aspect of JL Audio subs is the proprietary cone material that they utilize, called the W-Cone. It is a unibody assembly that is claimed to achieve an unparalleled combination of stiffness and minimal mass. Is it also said to have a shape that provides superior torsional rigidity for better voice coil alignment at the suspension limits. JL Audio eschewed materials like Kevlar, fiberglass, aluminum, magnesium and titanium alloys that are used by some competing brands. Instead they use two lightweight mineral-filled polypropylene skins bonded together at the perimeter and at the center of the assembly. The lower skin’s cross section is ‘W’ shaped so that it acts like the trusses of a bridge or the unibody construction of the chassis of an automobile to provide superior rigidity. JL Audio claims that their unique cone material has less weight per square inch of piston area than a typical aluminum-alloy or titanium-alloy cone.
So how do all these clearly superior (on paper) technical specifications translate to real world sound performance? To begin the audition, I played only the subs. This exercise revealed that the f112s have significant visceral impact and tautness at the lower octaves and they were totally non-localizable which is a clear indication of a superior subwoofer.
I played a wide genre of music from rock, heavy metal, pipe organ based classical, jazz, country western and Gregorian chants. My five favourite bass torture tracks that can make most speakers scream with pain are Sade’s Soldier of Love, Mussorgsky’s Pictures at an Exhibition, Cowboy Junkies Way Down Deep, Gerhard Oppelt’s Lindenkirche Berlin and Yim Hok-Man’s Poem of Chinese Drum. In every case, the f112 delivered all the advantages that a good sub would with hardly any of the downsides associated with this category of transducers. They blended seamlessly with my main speakers, dare I say, almost as well as the Scanspeak 8545 woofers blended with the Dynaudio Esotar tweeters in my main speakers. The role of the CR-1 was paramount in how well the f112s harmonized with my main speakers and my listening room.
Freed from the burden of processing and reproducing the frequencies below 50Hz, both my amplifier and my main speakers were able to produce prodigiously more dynamic range and they performed in a more effortless and relaxed manner than I have heard them do before. I was able to listen to my favourite tunes at a much louder level without the distortion and compression that I had experience at the same volume level before. The soundstage grew exponentially larger especially in depth, thus proving that a lot of spatial cues lie in the deepest bass portion of the music.
The f112s rendered the sub 50Hz bass with the accuracy, speed, coherence, pitch definition and tunefulness that I have heard in some obscenely priced full range speaker systems. I could easily decipher the difference between the bass guitar and the kick drum and also appreciate how well they complement each other. This was achieved authoritatively and without obscuring the delicate, nuanced and subtle details in the midrange and high frequencies. In addition they added fullness, roundness, weight and robustness even to the notes in the lower mid range. Voices had incredible presence and palpability. Metal music instruments like cymbals and triangles as well as drums sounded eerily real. Guitar strums sounded fuller and violins were sweeter and smoother. Wind instruments were distinctively more expressive.
I could not find any major downsides but if I were to nitpick, on the f112s, I’d prefer that the low pass control had the 80 Hz rather than the 75 Hz mark labeled because the former is by far, the most widely used frequency cut-off point. At $3,200, I would expect a remote control for the convenience of making adjustments from the listening position. I would also like to see a parametric equalizer and a variable high pass filter with an adjustable delay built into the unit. Subs far more affordable than the f112 offer many of these features so it makes these reasonable items for my wish list. Not every 2-channel system owner can afford a top-notch outboard crossover unit like the CR-1 so these additional features would help squeeze better performance from the JL Audio subs, sans an outboard crossover.
As for the CR-1 crossover, at its price, I would like to see a built-in high pass filter with a delay control option to slow down the signal to the main speakers by 1 to 18 ms to compensate for the typical group/time delay of the sound radiated by the subwoofers vis-a-vis the main speakers. Such a control will help compensate if the subs are placed further from the listening position than the main speakers. I would have also preferred to have the cut-off frequency option to go down to 30Hz rather than 50Hz to enable it to harmonize with speakers that do very well down to 30Hz.
I have reviewed many fine subwoofers and although I enjoyed my time with many of them, I felt no tinge of regret when returning them. The f112s are different. They are not going anywhere as they have now become part of my reference system, until something better (which I can afford) comes along, which I suspect will not be for quite some time. Kudos JL Audio, your f112 combined with your CR-1 gives music lovers a means to integrate superior subs with main speakers in a way that delivers deep, visceral, accurate and distinctively tuneful bass performance in a manner that will give anyone with a heartbeat, many goose bump inducing musical moments.
Distributed in Canada by Gemsen
JL Audio CR-1 Crossover
Price: $2,900 CAD (approx.)
JL Audio Fathom f112 Subwoofers
Price: $3,200 CAD