Hands On: JL Audio Fathom f112 Subwoofer
Features
Considering its features and supreme build quality, the Fathom f112 is relatively compact, but heavy at 115 pounds. The sub incorporates a black piano-gloss finish and black grille cloth that cover a front-firing, proprietary design 12-inch woofer.
The f112’s sealed enclosure houses a full array of amplification and electronics, including 1,500watt RMS amp. JL says frequency response is between 21Hz to 119Hz. If that’s not enough, JL’s Automatic Room Optimization (ARO) equalization technology helps deal with problematic low-frequency room modes.
The front panel has several control knobs, including a low-pass filter, JL’s Extreme Low Frequency control, phase and polarity controls, light dimmer, slave/master switch and master volume. The rear panel features XLR and RCA inputs, and master and slave inputs.
Setup
I placed a pair of f112s on Auralex decoupling platforms. I set up the subs in two configurations: one with each sub running independently using XLR cables and a Y-connector from the back of my parametric EQ, and the other a master/slave setup.
I used the Y-connector to split the LFE signal from my EQ to the left and right inputs of the subs. I set the volume of the units at 12 o’clock, turned off the low-pass filter, set the light indicator, set the level mode to variable and the ELF, phase, polarity, and turned on the auto-signal sensing option.
After listening, I reset the volume to 10 o’clock, which blended better for music and movies.
Moving onto the master/slave setup I turned off my EQ and ran a single XLR to the master input of the right subwoofer. I ran another XLR from the right sub’s output to the slave input of the left subwoofer. I plugged the calibration mic into the master sub input and mounted it on a mic stand in my money seat. After setting the controls, I pressed the EQ button to start the equalization process, which took a few minutes to complete.
Performance
I’m not going to mince words about the Fathom f112: It may be the best sub on the market.
The subs showed an immense amount of detail and power. They articulated the low-end of Rush’s Snake’s & Arrows Live DTS-HD Master Audio soundtrack on songs like Malignant Narcissism - including Geddy Lee’s fretless Fender Jaco Pastorius bass and Neil Peart’s massive drum kit - without crushing detail, speed, accuracy and space within the mix.
I had the same experience listening to Jeff Beck’s Live at Ronnie Scott’s Blu-ray disc, which features Tal Wilkenfeld on bass and Vinnie Colaiuta on drums. On songs like Cause We’ve Ended as Lovers, Wilkenfeld’s solo felt nearly as impactful and visceral as if I was standing next to her bass rig.
Movies were no different. On chapter 18 on the Transformers: Revenge of the Fallen, for example, the low-frequency content was loud and deep and didn’t overpower the mix.
Value
Considering that it may be the best sub in the custom market, the question of whether the Fathom f112 at nearly $3,000 MSRP offers value is a no-brainer: yes.
There’s nothing critical I can say about the Fathom f112. Its build quality, fit and finish are immaculate; it’s easy to install; and its performance is superb.
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6 Comments (displayed in order by date/time)
You know that JL has the F212, F113, and G213 subwoofers, right? The F112 is middle of the road in the line-up so why say it’s the “best sub on the market” when even within the same product line it isn’t the best? What subwoofers did you compare it with?
I’m aware of the company’s other products. The statement was made in comparison of other subs I’ve heard and reviewed. These include products from Wilson, Aerial, RBH and Revel among others.
We specd 2 gothams and the client did some research and chose 4 fathoms instead. The room is granite tile, a brick wall on one side and glass sliding doors on the other side with a 20 foot ceiling and zero sound treatment and these subs kick @ss.
Robert which method of hook up did you prefer in the end for sound? Independent or slave?
I own 2 x JL12’s and have moved away from LFE out back to stereo L&R preouts using Y on preamp. I largely listen to music and live music DVD’s and Bluray’s in PCM stereo. I much prefer this setup. Its been suggested to me I should run the sub inputs from the power amp loudspeaker outs.
The master/slave configuration streamlines everything, particularly the control. I had good results with both methods. If you run the EQ software you should be able to achieve a high level of sound quality.
In the end I do prefer the master/slave because it’s less work/tweaking to balance the output of both units.




For the record, in case anyone is wondering, I measured the sub using an RTA against my EQ. I compared those numbers to my room’s un EQ’ed readings.
The JL plotted very similar performance to my EQ and it worked well to smoothen midrange and low frequency room issues.