By Wayne Garcia, The Perfect Vision
November/December 2002

My thinking on subwoofers curiously parallels the crudest stereotypes you hear about men: Most of them are slobs; they place quantity before quality; they don’t mix well in groups, and they have an incredible knack for distorting the truth.

Let me emphasize that I have nothing at all against deep, visceral bass. When properly executed, a subwoofer not only allows us to hear low frequencies the way a musician or filmmaker intended, but adds a great deal of dramatic excitement to our listening and viewing experiences. And there’s the rub. Most subwoofers are not properly executed. With a few rare exceptions they fall into two camps: those that play really loud and go way down, accompanied by phase distortion galore and that dreaded one-note thump that makes you aware of the subs’ presence and separateness; or those that integrate reasonably well with the main speakers, are tight and tuneful with limited output, but would more accurately be described as woofers, not subwoofers—i.e., they don’t extend the frequency range to below 30 Hz.

My ideal subwoofer would reach down at least to 20Hz (it’s a rare recording or soundtrack that goes deeper), be phase accurate, integrate seamlessly with a wide variety of speakers, play loudly without strain, compression, driver noise, or cabinet resonance, and be detailed in both tone and texture. Oh, it would also be nice if it could be good looking, not cost a small fortune, and be smaller than a refrigerator!

Ladies and gents, meet the Martin Logan Descent

Some eight years in the making, the Descent comes closer to being my ideal subwoofer than anything else I’ve experienced. True, I’ve not had top contenders like the Krell Master Reference, Wilson WATCH Dog, or Audio Physic Minos in my room. But of the three only the Minos comes close to my dream woofer (and it’s still $5500, while the units from Krell and Wilson cost more than most of us can afford to spend on an entire system—$30,000 and $10,000 respectively—and are huge mothers to boot, with the Krell tipping the scales at 450 pounds).

"Some eight years in the making, the Descent
comes closer to being my ideal subwoofer
than anything else I’ve experienced."

Several factors contribute to the Descent’s exceptional performance. A major one is the trademarked BalancedForce technology that first appeared in the massive sub-bass towers of ‘Logan’s flagship electrostatic-hybrid design, the Statement E2. In a conventional subwoofer, when the driver moves back and forth an equal and opposing pressure is transmitted to the enclosure, causing it to resonate, or, as it says on MartinLogan’s Web site “dance.” As employed in the Descent, BalancedForce translates to three 10-inch aluminum drivers mounted 120 degrees apart. The result is—as ML’s accelerometer measurements show—as much as a 25dB reduction in cabinet resonance when compared with other fine conventional subwoofer designs. The six-sided cabinet is fashioned from inch-think “Ranger board,” which apparently is made only in Canada and which MartinLogan feels is “the world’s densest and most refined MDF.” I can only report that the Descent’s enclosure, which is not ported, is almost miraculously free of vibration. Perhaps most telling, with the Descent out of the system the sound from the main speakers—much to my surprise—was far less good (especially in the midrange) than it had been with the Descent looped in.

Like most of today’s finer bass drivers, the low-mass aluminum units used in the Descent have giant voice coils and huge magnets, and are capable of very long excursions. The speed and detail of these drivers (which lack the whitish coloration heard in some aluminum-cone designs) are of paramount importance with the Descent (as well as in MartinLogan’s latest hybrid-electrostatic modes—easily the most completely integrated the company has yet made). And so is the servo-monitoring circuitry employed here, which, despite introducing its own design challenges, demonstrably and significantly lowers the harmonic and intermodulation distortions of cone drivers, and especially long-throw bass drivers.

"...the kick drum came through with a jolt
that you can really feel, while each note of
the bass guitar and the weight, rumble,
and tunefulness of the real animal."

Power is supplied by an internal 400W proprietary switching amplifier (capable of 800W peaks with very low distortion). A choice of just two crossover points is available through the line-level inputs: 70Hz for use with “bookshelf” speakers and 40Hz for fuller range floorstanding designs. For home-theater application you’re more likely to feed into the LFE input and select the crossover point via you’re A/V controller. (I tried it both ways with equally satisfactory results.) And here it is worth noting, as MartinLogan’s colorful president Gayle Sanders did in a recent chat, that the extensive work that went into these filters is another reason the Descent does its job so well. While singing the praises of ‘Logan engineer Joe Votko, Sanders explained to me how similar the roll-off characteristics are between bookshelf and floorstanding speakers. To enable the Descent to work “in consort” with either kind of loudspeaker throughout the crossover region, Votko contoured the low-pass filters to conform to the main speakers’ roll-off pattern at each crossover point, placing particular emphasis on maintaining octave-to-octave phase and time coherence.

The remaining controls—tucked behind the front driver’s grille—are for power, phase (at 0, 90, 180, and 270 degrees, these allow for maximum flexibility of placement in a room), output level, and a ±12dB swing at 25Hz. There’s even a three-way toggle to dim or shut off the blue MartinLogan logo—a swish that makes Nike’s look downright stodgy.

To sweeten the deal, the Descent is an unusually attractive subwoofer. Its hexagonal cabinet is of moderate size and available in a choice of (interchangeable) wood trims options, making it something of a looker in a group of generally brutish competitors. At $2795 the Descent isn’t cheap, but its value speaks for itself.

As indicated earlier, what makes the Descent so remarkable is not simply the quality of low frequency information it adds to existing speakers, but what goes missing—in addition to the bass—when you take it out.

"...the Descent had a feeling of endless
power in reserve without ever seeming
disembodied from the whole."

On Elvis Costello’s “45,” the opening track from his terrific recent CD When I was Cruel, there are two interesting workouts for a subwoofer—a fat, relentless, and gut-thumping kick drum that is followed by an electric bass with snap, weights, and subtle tone color. With the Descent in the system—it’s not difficult to dial in, by the way—the kick drum came through with a jolt that you can really feel, while each note of the bass guitar and the weight, rumble, and tunefulness of the real animal. The song is a driving rocker that begs to be played loudly, and once unleashed the Descent had a feeling of endless power in reserve without ever seeming disembodied from the whole. Instead, and rather shockingly, the sound did become disembodied when I took the Descent out of the system. Costello’s voice sounded as if it were coming from a head in search of a body, so anemic and lacking in weight did it become, while the instruments were scrunched together spatially and dynamically, and the soundstage simply collapsed. As was expected, the bass drum morphed into a mere finger flick on a Folger’s can, and the bass guitar turned into a one-note drone lost somewhere in the mix.

The Descent’s virtues were equally apparent with multichannel sources. Wynton Marsalis’ rhythm section (on The Best of Sessions at West 54th Volume One music DVD) had great drive and power with the Descent, and was in need of Viagra without; the “Can-Can” sequences in Moulin Rouge was exceptionally deep, impactful, and complete, while the “whup, whup, whup” of the helicopters in Apocalypse Now Redux, along with the Doors’ “The End” helped create an immense sonic landscape, far larger, more enveloping, and psychedelic than I’ve heard with other woofers.

Although it was designed for and will most likely be used in systems with MartinLogan’s own electrostatic-hybrid speakers, the Descent is a truly great subwoofer that will match beautifully with other manufacturer’s speakers (I also tried it with Naim Allaes).

Gayle Sanders told me that it took eight years and countless prototypes—including a huge and potentially lethal electrostatic woofer—before he felt MartinLogan had something truly special to offer. Gayle, it was worth the wait.