HOME THEATER & SOUND -- www.hometheatersound.com


Reviewed by
Randall Smith

JL Audio
Fathom f113 Subwoofer

Features SnapShot!


Model: Fathom f113

Price: $3200 USD
Dimensions: 19.5"H x 16.5"W x 19.75"D
Weight: 130 pounds

Warranty: Three years parts and labor

  • 13" W7 driver
  • 2500W amplifier (manufacturer rated)
  • Unbalanced RCA inputs (stereo, mono)
  • Balanced XLR inputs (stereo, mono)
  • Output to slave (balanced)
  • Two input modes (Master, Slave)
  • Two level modes (Reference, Variable)
  • Variable low-pass crossover (frequency and slope)
  • Adjustable polarity
  • Phase variable, 0-280 degrees
  • E.L.F. Trim
  • Automatic Room Optimization, including microphone and XLR link

In September 2004, car-sound specialists JL Audio sent out a press release announcing their intention to "push the boundaries of bass reproduction in audio and home-theater systems" with their first line of active subwoofers for the home. Three different subs were announced: the Fathom f112, the Fathom f113, and the Gotham g213. Buyer anticipation began to grow, and continued to build for some time, if only because not one of the above-mentioned models ever made it to market. Release date after release date was pushed back, until I began to wonder if JL’s subs had any reality at all.

In January 2006, I stumbled my way around the car-audio displays at the Consumer Electronics Show, looking for the JL Audio booth. I wasn’t interested in the incredible sounds coming out of the demo cars. I had one goal: to see and hear JL’s home subwoofers. I finally interrupted one of the JL reps at the car booth to ask him where the home-theater demo was being held. "The Mirage," he said. I quickly left the Las Vegas Convention Center and took the monorail to the strip.

At the Mirage I met Brett Hanes, JL’s senior research engineer and the man in charge of the home-audio demo. He was standing next to an imposing Gotham g213 sub, which I later learned was not a working model. After an exchange of pleasantries, he quickly introduced JL’s Fathom line of subs before playing a few music and movie selections to demonstrate their capabilities. The demo was very impressive. On the way out, I asked the one question the demo had not answered: "When will they ship?" Hanes’ little smile told me I’d asked a question he must have heard a hundred times that day. "The end of next month," he said. I said goodbye and, as I walked out the door, cast one last look back at the Gotham, thinking, I wonder when I’ll get to hear that beast.

Such anticipation for a new JL Audio product is nothing new, I would come to find out. The company has a reputation for pushing back a product’s launch date until they feel they’ve gotten it just right -- a commendable quality in a market that demands everything right now.

Then, almost two years after the first press release about the Fathoms, a boxed-up Fathom f113 ($3200) was delivered to the lobby of my office. Lucky me!

Unpacking and setup

My review sample of the Fathom f113 was packed like precious cargo. Four green plastic balls on the bottom of the box act as shock absorbers during shipping. They raise the box a few inches off the ground and protect the cardboard from water damage. On the sides of the box are two handle slots to aid in the carrying of the sub, which, for its relatively small size, is quite a load: 130 pounds. The handles are a big help. I lugged the box into my listening room and followed the instructions printed on the top to safely remove the sub. Inside, the f113 was enclosed in a protective velvet bag, which made it seem even more special. Did I say "precious cargo"?

Having finally freed the f113 from its packing, I donned the (supplied) white gloves and carefully positioned it. Then I removed the sturdy grille cover to reveal the massive 13" driver. The cone itself is a modified version of the legendary (in car-audio circles) W7 driver, which JL created and manufactures in-house. To take advantage of the cone’s considerable peak-to-peak excursion capabilities -- well in excess of 3", I’m told -- JL needed a "prodigious amount of controlled power." Through intense analysis, their engineering team "produced a pair of precisely engineered switching amplifiers employing patented technology . . . capable of unclipped output voltages equivalent to 1500W (f112) and 2500W (f113) of RMS power when referenced to the nominal loudspeaker impedance." All of this technology is housed in a well-braced, attractively sealed case that seems designed to handle abuse.

I connected my Anthem AVM 20 preamplifier-processor to the balanced mono input on the rear of the f113. When I then pressed the Demo button on the sub’s front, I was treated to some sweeping bass tones. At this point I was way too eager, but I still had to complete one final process: JL’s Automatic Room Optimization (ARO) program, which is a primary feature of the f113. This process uses a single-band parametric filter to equalize the main offending frequency peak and thus achieve a flatter frequency response. To remove problematic bass resonances, I have in the past used my Anthem AVM 20’s notch-filter function, but have noticed that the bass response, while flatter, was also duller (i.e., not as lively). I hoped the ARO feature would improve my room’s low-frequency linearity. I connected JL’s special testing microphone to the f113 via an XLR cable (both are supplied with the sub, and come in a nice storage pouch) and pressed Calibrate on the front-mounted control panel. The sub was then subjected to two minutes of test tones covering the full spectrum of low frequencies. When the process was completed, the Calibrate button lit up solid green.

I then grabbed a test CD and my RadioShack SPL meter to measure my room’s bass response. It was much improved. The unequalized peak had been +8dB at 40Hz, with a -6dB dip at 80Hz. After calibration, the peak was +5dB at 50Hz, with a -2.5dB dip at 20Hz. I improved those figures even more by tweaking the f113’s Phase and Polarity controls, also conveniently placed on the sub’s front, but, like the rest of the front controls, are hidden when the grille is attached. With the polarity switched to 180 degrees and the phase set to 275 degrees, I was able to smooth out the 50Hz peak by cutting another 2dB, which produced a peak of only 3dB.

Using the ARO calibration in my room required identifying my front speakers as Small, and setting the crossover frequency higher (both changes made via the Anthem AVM 20). Usually, I find that the best crossover point for movies is 80Hz, but for music, I like to run my Aerial 10T speakers full-range, and let the sub help out only in the lowest frequencies. I quickly had to get over that mindset, and understand that in order to achieve the best bass response in my room I needed to let ARO do its thing. ARO can’t fix a peak or a dip created by sound from the 10Ts, so crossing over to the sub at 65Hz was appropriate for music and provided the flattest response. Very impressive results on paper, but would the ARO’s EQ stifle the sound?


I threw everything at the Fathom f113. From the depth charges in U-571 to the cannon fire in Master and Commander: The Far Side of the World, all my usual demo material exploded in ways I had never experienced in my home, and set a new reference level. The visceral impact of the cannons kicked like a mule -- deep, strong waves of bass barreled through my room, quick and relentless. It was the kind of bass that makes your eyeballs rattle. The depth charges in U-571 seemed to the suck air out of the room just before they hit. Although the f113’s volume level was relatively flat in relation to the level of the rest of my speakers, the sub was a clear standout with its explosive and dynamic presence. A friend who sells JL car products stopped by and was blown away by the sub’s performance as properly calibrated, but he wanted even more. He switched the Level mode from Reference to Variable and turned the level much higher. Normally I’d be concerned for the sub’s safety, but he assured me that a JL woofer is almost "indestructible" -- our bodies and my home were what was in danger. He cued up the scene again and I scurried out into the front yard. The explosions sounded just as clean and dynamic outdoors as they had inside at the lower volume. I was amazed.

Brett Hanes described to me a test he performed late in the Fathom’s development process. He placed an f113 in the middle of a parking lot, turned it up, and measured the sub’s output: Outdoors, with no room reinforcement, it was an outrageous 121dB at 1m. As impressive as this anecdote is, I already knew that the Fathom f113 had more headroom than any other sub I have experienced.

Even compressed cable signals sounded great in the bass. Fed compressed signals from HBO-HD’s broadcast of Flight of the Phoenix and War of the Worlds, the f113 created big, theater-like bass. The crash scene in Phoenix is so well done -- the effects of the spinning plane are witnessed on the faces of the actors, and I felt it in my room. Surround sound is used to re-create the sensation of spinning, the sub kicking in to provide the pressure of the G forces. Waves of unfathomable bass exerted a pressure on my body that I had previously felt only in the lift-off of an actual airplane. It was that intense.

War of the Worlds is full of big visual and audio special effects. One effect that hadn’t stood out with my previous sub but that quickly became apparent through the f113 was the low rumble of bass when the first Tripod begins to rise. The sound was so low in frequency that it would be inaudible with some subs; the f113 re-created it in a way that I’ve never felt outside of the theater. The sound was deep, with no audible distortion at all. It was smooth, solid, and layered with detail, without showing any weakness. I could sense the size and mass of the object rising from the ground.

I was now convinced that JL Audio had produced a dynamic sub of incredible output capability. But could the Fathom f113 produce quick, detailed bass while meshing its sound together with that of my Aerial 10Ts?

Diana Krall’s The Girl in the Other Room [SACD/CD, Verve B0002293-93] gave the Fathom f113 ample opportunity to reveal any weakness in this department. Only acoustic instruments are used on this disc, and almost every song has a snappy bass line that sets the pace for Krall’s sultry voice. "Temptation" opens with a superb double-bass line that drives the entire song. Clean and quick, the f113 didn’t draw attention to itself. The two front speakers produced the higher frequencies of each plucked string, while the weight of each note was carried by the sub. So seamless was the combination that I marveled at the Fathom’s ability to "disappear." This concentrated little package delivered the bass in a powerful yet delicate, agile manner well suited to this acoustic album.

For a more authoritative sound, I turned to Donald Fagen’s most recent release, Morph the Cat [CD, Reprise 49975-2]. I expected a great recording from Steely Dan’s front man, and he didn’t let me down. The title track begins with a thunderous bass line that’s characteristic of the rest of the album. Again, the Fathom f113 produced deep, rhythmic bass that was clean and musical.


My reference subwoofer, the SVS PB12-Plus/2, is an incredible value at the price ($1199), and I continue to recommend it highly. In fact, some of the biggest differences between the JL and the SVS are in size and price: the SVS is three times the size of the Fathom but costs only a third as much. The SVS has two 12" cones and the Fathom a single 13" driver, but what the JL lacks in size it makes up for in driver capability and amplifier power. The f113 has some of the most advanced technology I’ve seen: the legendary W7 driver is a sight, and the ARO circuit helped me get flatter bass than ever before. Simply put, the Fathom f113 provides more possibilities. As for sound, the JL played deeper, louder, and tighter than the SVS with any material I chose. But this statement doesn’t apply only to the SVS PB12-Plus/2; it applies to every other active sub I’ve heard, at any price. The JL Audio Fathom f113 has become my new reference subwoofer.


Good things come to those who wait. JL Audio may have jumped the gun a bit by issuing a press release that promised a groundbreaking line of home subwoofers almost two years before they actually shipped one, but now all is forgiven. Their level of achievement in this first venture into home audio is truly impressive. The Fathom line of subs is a shot across of the bows of competitors that signals the arrival of JL in the world of high-end home audio. With JL’s in-house technical and production facilities, I expect great things from them. You may have to wait a while for it, but when you get a product that bears the JL Audio logo, you can feel confident that it’s the real deal.

The JL Audio Fathom f113 is the single best A/V product I have experienced. The improvement it made to my home-theater system was stunning. I’ve never heard better.

Review System
Speakers - Aerial Acoustics 10T (mains), CC3B (center); Von Schweikert VR-1 (surrounds); SVS PB12-Plus/2 (subwoofer)
Preamplifier-Processor - Anthem AVM 20
Amplifiers - Anthem MCA 50, Krell KSA-50S
Sources - Denon DVD-2910 universal audio/video player, Toshiba HD-XA1 HD DVD player
Display Device - Sony KV-36HS420 direct-view monitor
Cables - Nordost, Monster Cable, DH Labs
Remote Control - Universal Remote Control MX-850 Aeros
Power Conditioners - APC H15, Goertz BP1000

Manufacturer contact information:

JL Audio
10369 North Commerce Parkway
Miramar, FL 33025-3962
Phone: (954) 443-1100
Fax: (954) 443-1111

Website: www.jlaudio.com

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