JL Audio f113 Fathom Dialed In

[jdandy]

I sat down this morning and read the JL Audio f113 Fathom manual cover to cover. Then it was time to flip the power switch on, and see what this bad boy can do. I am feeding the sub with left and right balanced connections, and the first thing I noticed was it is absolutely silent. If the Fathom didn't have a light indicating the power was on, you wouldn't even know it, dead silent. I started my initial audition just as the manual suggested, gain straight up, polarity set on zero, phase on zero, crossover at 85 Hz, and the low pass filter slope set to 12 dB.

I began with Brian Bromberg - You Know That Feeling, "Hero". Whoa!!! Too much volume, so I backed off the gain from 12 o'clock to about the 10 o'clock position, and it was much better. The f113 Fathom is a powerful brute, and it goes DEEP. I played with the polarity switch, and discovered zero is the place to be. I played with the crossover point, and discovered 70 Hz was where the sub and the PMC's melted into each other.

Next, it was time to try the Automatic Room Optimization functions. I looked around the room, moved all loose standing items to the floor in the dining room, and made sure there was nothing that could fall from vibration. Again, I followed the directions exactly, made the proper settings, plugged the special microphine into the sub, attached the mic to a boom microphone stand, and positioned the mic at ear level in my sweet spot seating position. Having the mike on the boom stand really helped. I shut off the central air conditioning system as instructed, and proceeded with the testing. I pressed the calibrate button, and the tone pulses and tone sweep began, and then stopped. I looked at the calibrate button, and it was blinking slowly. The manual tells me this means I need to raise the gain, so I did. I pressed the calibrate button again, the tone pulses and tone sweep began, and then stopped. The calibrate button was blinking slowly again. I turned up the gain this time to about the 3 o'clock position, and pressed the calibrate button again. This time the tone pulses and tone sweep continued, getting progressively louder, while gradually creeping up in frequency. This sub puts on quite a show, let me tell you. If there is anything that can vibrate in your listening room, it will. The test frequency sweep finally ended (about 2 minutes or so), and now my calibrate light in the center of the calibration push button is glowing steady, which means my calibration is complete, and the adjusted curves are stored in memory. This feature is unique among subwoofers, and is a powerful tool for dailing the sub to the room acoustics.

The manual now tells me to reset the gain to the level previously adjusted before the calibration sweep, so I returned the gain control to the 10 o'clock position, settled on the 24 dB slope for the low pass filter roll off, set the crossover point to 80 Hz, the phase to zero, and the e.l.f. trim to zero. Back to Brian Bromberg's CD I go. As I am listening from my sweet spot, I am noticing how much deeper the Fathom f113 goes than did the XLS112, and so effortlessly, with no bloat. On my preamp I am switching the speaker 2 output (the sub's feed) off, and on, comparing the sub to the PMC's directly. A small adjustment to the crossover point improved things when I set the point to 70 Hz. Above that point the lowest of the midrange gets a tiny bit heavy, but at 70 Hz the sub just disappears.

I played several other CD's, Gregg Karukas - You'll Know It's Me, Paul Brown - The City, Paul Hardcastle - 5. These CD's all have tight electric bass, some mixed with synth bass, and strong bass drum. Switching the sub in and out while listening to these CD's helps tremendously in making the finer adjustments for gain. I have also determined that my e.l.f. trim setting helps remove a faint room boundry boost when set to the -2 dB setting. I attribute this to the size of my room, which at 12' x 17' with an 8' ceiling, and is not that large a space for a sub of this caliber and power.

At this point I have not decided on any particular phase setting, which the manual describes as adjusting the timing of the subwoofer output relative to the main speakers, and primarily affects the frequency range around the crossover point. The manual goes on to say that if no single phase setting sounds better than another, leave the Phase control at zero. For now, this is what I have done.

There will be plenty of time to tweak adjustments as I listen for more extended periods of time, but for now the f113 Fathom is dialed into the PMC EB1i's so smoothly that you do not sense it is there, but you know it is there. The bottom octaves are richer with it in the system. It has been said that the JL subs are quite musical, and I have to agree. With the XLS112 in the system, I kept the crossover set at 45 Hz. Above that, and the sub tended to add a color to the sound that I did not prefer. The f113 Fathom, crossed over at 70 Hz is invisible, and blends perfectly with the PMC's. I could not ask for more. And let me tell you, when you raise the volume, this sub moves some air, literally. When I bent down in front of it to make a tweak of one of the controls, it got down right windy. Really! This sub is amazing, and lives up to my highest expectations.

Before sitting down to write this review, I played one of my favorite CD's, Liz Story with Joel Di Bartolo. Liz plays piano from her heart with complete conviction, and Joel's acoustic double bass is perfectly blended with her playing. The track "The Very Thought Of You" I have listen to so many times I know every single note of both instruments. Tonight, for the first time, I heard a magnificent new weight to the bottom octave of the keyboard, such that now more than ever before her piano timbre and overtones approach that of the real instrument being present in the room. I have always been enamored by the sound of piano notes, and used to play my mother's piano often when I was younger. Striking chords or single notes on the lowest keys, and holding them so that the notes are sustained, and then diminish has always been moving for me. This is exactly what I am now hearing and experiencing with the Fathom in my system. It is such a thrill.

I can't imagine the JL Audio f113 Fathom subwoofer not blending perfectly with any speaker system. All the tools necessary are built right in to allow this wonderful sub to play nice in any environment. Not only is the subwoofer able to create serious deep bass output when called upon, it does it while wearing a velvet glove. And it is a beauty to look at, too. The gloss black finish could not look any finer on a Rolls Royce. If you are even thinking about a subwoofer for your system, this is the one to get. Highly recommended.

[Masterlu]

Are you testing the 10,000 word limit?

Nice write up as always Dan!

[jdandy]

Originally Posted by Masterlu

Are you testing the 10,000 word limit?

Nice write up as always Dan!

Ivan.......I didn't count the words, so I can't say. No doubt, I probably could have gone on, but I wanted to get the review posted this evening.

[Masterlu]

Word count, 1258...

[jdandy]

Originally Posted by Masterlu

Word count, 1258...

Shoot! That doesn't amount to a good short essay.

[JFR0317]

Yet another great review by Dan!

I am so glad you are enjoying your new sub. The JL's are indeed special.

I can hardly wait until Sunday afternoon to experience Ivan's Gothams!

[Masterlu]

My Twin Gothams are "Bambi & Thumper"!

[JFR0317]

Originally Posted by Masterlu

My Twin Gothams are "Bambi & Thumper"!

I'm sure they are "deer" to your heart!

[Masterlu]

Cute!

[Still-One]

Dan

Nice review. I am glad that the sub is integrating so well with your speakers.

Jim