The Power Sound Audio S3600i subwoofer showed me that, even after 25 years of reviewing audio products, I haven't heard everything. Nor have I lost my capacity to be surprised, delighted, and a little frightened by a subwoofer.
A glance at the spec sheet shows the S3600i ($1,749.99) is one of the most muscular subs available today. Its sealed cabinet holds two 18-inch drivers in a diametrically opposed arrangement that cancels vibration. An ICEpower Class D amp provides 1,700 watts of rated power. It's 20 percent larger by volume than the Hsu Research VTF-15H, the hulking subwoofer I use as a testing standard.
At 20 by 28 by 24 inches and 137 pounds, the S3600i is too big to plop just anywhere. It's intended for large, serious home theaters and stereo systems, not for average living rooms. Its industrial-style textured satin black finish makes it look more like a P.A. cabinet than a consumer product. Maximum output is rated at an average of 132.1 dB between 40 and 63 Hz, quite a bit higher than the 126.9 dB I got from the Hsu VTF-15H Mk2, the most powerful conventional sub I've measured to date. (I measured 135.5 dB from the Pro Sound Technology LFC-24SM; but, at 266 pounds, 60.5 inches wide, and $10,000, that's not a conventional subwoofer.)
A look at the back panel makes it obvious that the S3600i is a sonic muscle car, designed for output and bereft of the numerous adjustments and features found on many other higher-end subs. Of course, it has the usual gain (volume) and crossover controls, with the latter adjustable from 40 to 150 Hz.
However, it does have two unusual features. A delay control, adjustable from 0 to 16 milliseconds, lets you align the subwoofer acoustically with the main speakers. This takes the place of the usual phase switch or knob. Normally delay is adjusted inside the AV receiver or surround sound processor, in the "distance" settings for the different speakers, but this adjustment will come in handy for 2.1-channel systems. There's also a room size control, which can attenuate the deepest frequencies to compensate for the room gain you get using a large subwoofer in a small room.
Now it's time to find out if this sub can live up to its claims--and if it can do so without sounding like a booming car stereo, which is what I think a lot of us would expect from 18-inch drivers.
The S3600i fit into my room's "subwoofer sweet spot"--the place in my listening room where most subs sound their best--but just barely. With a sub this big, you may find your placement options more limited than usual. The only inputs are two line-level inputs, so I connected the top one of these to the subwoofer output of my Denon AVR-2809CI receiver, and later to the subwoofer output of the Classé Audio CP-800 preamp/DAC I use for stereo speaker reviews. The downside here is that there's no speaker-level connection to use for simpler stereo systems, although you can run stereo line-level signals into the inputs from your preamp.
I used an AudioControl Savoy seven-channel amp with the receiver and a Classé CA-2300 amp for the two-channel setup. For surround sound, I used Sunfire CRM-2 and CRM-2BIP speakers; for stereo, I used Revel Performa3 F206 tower speakers. In both systems, I set the crossover frequency to 80 Hz, so the subwoofer would have to handle the full bottom two octaves of bass on its own.
The delay control came in handy when I was using the Classé CP-800, which has a built-in subwoofer crossover but no speaker distance adjustment. To set the delay, I simply played a pink noise signal, placed my head roughly equidistant from the S3600i and one of the Revel speakers, and turned the delay knob until I got the fullest bass response (about the 12 o'clock position, but your optimum setting may vary).
Because my room is large (about 2,950 cubic feet) but not huge, I set the room gain setting to the three o'clock position. I also tried using it set all the way large. It wasn't a big difference; it seems my room is large enough not to have room gain problems with this sub.
The downside of this sub from an ergonomic standpoint is that it's hard to get to the controls. Reaching around the back of such a big sub isn't easy even if you have long arms. I'd prefer to have the controls moved to the front, maybe concealed behind a cover. Since appearance doesn't matter in my listening room, I simply turned the S3600i 180 degrees so the controls and jacks faced forward.
I have hosted some awesome subwoofers in my listening room over the last 13 years. I thought the best of them were all anyone could need for a room the size of mine. I was wrong.
My first experience with the S3600i was playing the Blu-ray disc of San Andreas, the earthquake movie starring Dwayne "The Rock" Johnson and Paul Giamatti. As I so often do, I got the disc running then went to refill my iced tea, so I'd skip all the annoying studio and production company trailers at the beginning. But San Andreas kicked in fast with a scene in which a girl driving a car gets caught in a rockslide; even though the system wasn't turned up super-loud, the sound made my kitchen cabinet doors rattle fiercely. That has never happened before, not even with the terrific subs I've tested in the past. When I scooted back to my listening chair, I could feel the S3600i pressurize the room and shake the house's foundation as no sub I've tested before has been able to do. Worried I might crack my drywall or rattle something off a shelf two or three rooms away, I backed off the volume. Later, when fellow AV writer Geoff Morrison stopped by and wanted to hear what this huge sub could do, I played the scene from San Andreas where Hoover Dam collapses, which sold him on the S3600i right away.
My guess is that most of the people interested in a sub with dual 18-inch drivers will focus on movies, so I'll start with my all-time-favorite subwoofer test scene, the "Face to Face" and "Depth Charged" chapters of U-571. I love this scene because it provides a few different bass tests, all of which revealed something about the S3600i's performance.
"Oh, yeah!" I exclaimed when the submarine's crew fired their deck cannon at the enemy destroyer. Many subwoofers don't have enough kick on this sound effect; they make the cannon blast sound more like someone whacking a metal trash can with a baseball bat. Through the S3600i, the deck cannon sounded more like a real naval cannon, delivering a powerful "whomp" of compression against my chest and a firm shake of my home's concrete slab. (How do I know what a real naval cannon sounds like? Because I was on the USS John Paul Jones when it fired its five-inch cannon during Friends and Family Day a few years ago.)
However, during the toughest part of this scene, when the submarine dives under the destroyer and both ships' engines rumble loudly and deeply, the S3600i actually sounded quieter than most of the big subwoofers I test. This wasn't because it lacked the oomph to play the deep notes, it's because it didn't have to strain to play the deep notes. Thus, its distortion harmonics--which are easier to hear than the fundamental tones because they're higher in frequency--were lower in level during this test than they are with the other subwoofers I've tested.
Last came the depth charges, which had more power and shake than I've ever heard before with any other system, including many custom-installed home theaters on which I've played this scene. I was amazed at how the S3600i pressurized the room, much the way I've felt when hearing ordinance exploding during simulated attacks at military air shows.
The S3600i almost seemed to sleep through the opening of Edge of Tomorrow, which starts with extremely deep, loud bass notes that have bottomed out a couple of subwoofers I've tested. And that's with the level cranked so loud that my ceiling (which is made from a dense, circa-1960 application of inch-thick sprayed plaster over drywall) creaked.
Let's admit it: Most of us would assume that a sub so large and powerful sounds sloppy and boomy with music. But the S3600i actually sounds "fast," probably because it uses pulp-cone woofers, which tend to be light in weight yet have a natural damping character that quells high-frequency distortions.
For example, on "Casa Loco" from guitarist Steve Khan's fantastic album of the same name, all the bass notes sounded perfectly smooth and even. The lowest notes swelled, filling the room without booming or excessively resonating. That's exactly the way a bass works; plug any electric bass into a good amp, pluck some high and low notes, and you'll hear what I'm talking about. The groove was right on top of the beat, with zero delay or lag; it pretty much sounded like my Revel F206s had grown a whole lot bigger. The sound reminded me of what I've heard from well-calibrated professional subwoofers in top-notch recording studio control rooms.
The S3600i produced the best pitch definition I have ever heard on the descending synth-bass line in Olive's "Falling," and I've been using this as a test track since writer Al Griffin introduced me to it in the late 1990s. Most of the big subs I've tested can play this track without distortion, but none ever played these low notes with the grace and subtlety of the S3600i.
The S3600i also sounded gratifyingly tight on well-produced, precisely played pop and rock tunes, such as Toto's "Rosanna" and Mötley Crüe's "Kickstart My Heart"--easily reproducing even the most dynamic kick drum hits without the slightest trace of lag or slowness. In fact, I was surprised that this ability to capture any groove perfectly--or, as many audiophiles would say, get the pace and rhythm right--was one of the things I liked best about the S3600i.
Click over to Page Two for Measurements, The Downside, Comparison & Competition, and Conclusion...