JL Audio E-Sub e110 Subwoofer

Old Dog, New Trick

Equipment report
JL Audio E-Sub e110
JL Audio E-Sub e110 Subwoofer

It is no secret that I’m not a fan of subwoofers. In my experience they take away more in transparency and coherence than they pay back in low-end extension and power-handling, especially when they are mated to bass-shy two-ways or any kind of planar, ’stat, ribbon, or quasi-ribbon. (Ironically, subwoofers work best—or at least better—with speakers that don’t really need them, i.e., with dynamic speakers that already have good bass extension.) Thus, it may come as a surprise to learn that I really like JLAudio’s e110 sub, even when it is paired with a two-way. It certainly came as a surprise to me.

The e110’s price tag may also come as a surprise—$1500 in what JL calls its “black ash” finish, and $1700 in the gloss-black version sent to me. This isn’t exactly cheap for a single ten-inch driver in a small (13.5" x 14.25" x 16.5"), hefty (53-pound), sturdy box, but it isn’t Thor’s Hammer or JL Audio Gotham (or even REL Series R) territory, either.

What you get for that grand-and-a-half is a highly engineered loudspeaker that incorporates many of the patented Finite Element Analysis-based technologies that JL Audio has been introducing since 1997—such as its Dynamic Motor Analysis program for computer-optimizing driver design, its Vented Reinforcement Collar driver-mount system, its Floating Cone Attachment method of driver construction, and its Engineered Lead-Wire System for internal wiring. You also get a built-in, proprietary Class D amplifier (powered by a proprietary switch-mode power supply) said to be capable of 1200W RMS; a genuine two-way (high-pass and low-pass), built-in, active crossover using a fourth-order (24dB/octave, 80dB/decade) Linkwitz-Riley filter, equipped with variable gain, variable crossover-frequency, and variable phase controls, as well as a polarity (absolute-phase) switch; a ten-inch JL Audio woofer with dual spiders and a linear motor system engineered to provide equal force over the driver’s entire excursion range (with both positive and negative current flowing through the coils) at any applied power level up to the built-in amp’s peak; and a sealed box whose entire front panel is actually the steel mounting flange of the E-Sub’s driver assembly (the back plate of the driver is threaded and bolted to the thick rear wall of the enclosure). In sum, the e110 represents a lot of technology for the money.

As anyone who’s fiddled with subs knows, setup is at least half the battle when it comes to getting the most out of a subwoofed system, and I can honestly say that JL Audio (for whom subwoofers are a long-time labor of love) provides some of the sanest instructions and most useful tools for optimizing its subs I’ve seen—provided that you first acquire the right software. That software, which was sent to me separately by JL Audio (it doesn’t come with the sub—and I think it should), is the Soundoctor Test CD V 2.6.1, available (for $18) online at http://www.soundoctor.com/testcd/index.htm.

Without this CD (or something similar) you will just be making educated guesses when it comes to certain key adjustments, which means, of course, that you will be haunted by second and third guesses since you’ll never be quite sure whether your first guess was “right.” With the Soundoctor CD (and the Radio Shack SPL meter for which it is optimized) you can dial certain parameters in with confidence, giving you a “textbook accurate” baseline, from which you can depart or to which you can return as you season the sound—and you will season the sound—by ear.

The first step in the set-up process is finding the spots where the subs are happiest in your listening room. What JL and Soundoctor suggest is to place one sub at your listening position, facing forward, then plug a CD player directly into the sub’s RCA inputs (using the CD player’s analog outputs), and play back Tracks 22, 23, and 24 of the Soundoctor CD, which contain music with very deep bass. As these tracks are playing, you crawl around the perimeter of your room listening for those areas where the bass sounds weak and thin or those where it sounds boomy and ill-defined (usually in the corners). According to JL, you should also find certain spots where the porridge is just right, and these are where the subs go.

To be honest, this “crawl-around” method is rather hit-and-miss. It also assumes that the subs will sound better somewhere along the perimeters of the room, which hasn’t always been the case in my experience. Typically, I’ve found that for the transparency and coherence I prefer (as opposed to ultimate slam and extension) subs fare better close by the main speakers, immediately to the outside or the inside (or both, as explained in the sidebar) of the speakers’ enclosure and roughly parallel to their drivers, although the subs’ exact location vis-à-vis the mains and the sidewalls needs to be adjusted by ear.

Far more hit than miss are JL’s suggestions for getting the subs and the mains in phase. A subwoofer’s phase control is intended to adjust the “arrival time” of the sub’s output so that its driver and the main speaker’s woofer or mid/woofer or bass panel are pushing and pulling together throughout the frequency range covered by both units. The question is how can you tell when the drivers of both speakers are in maximum sync? With the appropriate tracks on the Soundoctor CD and the e110’s continuously adjustable phase control, finding the answer to this often-perplexing question is a snap.

For the record, JL Audio recommends the same method that Robert Harley recommends in The Complete Guide to High-End Audio: Reversing polarity on the main speakers, playing a test tone at the crossover frequency (Tracks 2 through 17 on the Soundoctor CD give you one-minute test tones ranging from 20Hz to 120Hz at 5Hz and 10Hz intervals), and adjusting the continuously variable phase control for the least amount of bass. As Robert explains it: “The technique works because it’s easier to hear the maximum null than it is to hear the maximum peak. When the phase control is set perfectly, the main speaker’s woofers will move out when the subwoofer cone is moving in, cancelling each other. When the main speaker’s correct polarity is restored, the main speakers and the subwoofer are maximally in-phase.”