Subwoofers - DIY vs. commercial

Has anyone here built your own subwoofer? I'm moving to NYC in the fall for law school, and there's simply no room to put my current subwoofers (4 Paradigm Servo-15's) in my fiancee's flat. High-end subwoofers are pretty expensive, especially since to get good response at multiple listening positions you really need three or four placed around the room. Also, many of the nice-looking compact subwoofers (such as Velodyne's Digital Drive series) seem to duplicate processing my TacT TCS (which is very much going with me) already provides. But the only subwoofer cabinets I've ever built were for car audio systems. Is there any secret to building home subwoofers or would I be happy with something like the three of the passive radiator system shown here? (I've been told that the Peerless XLS is same woofer used in the url=http://www.genelec.com/products/7070a/7070a.php]Genelec 7070A sub,[/url] so it should be a good timbral match to my Genelec mains. I believe it is also the woofer used in the highly-regarded - though I've not heard it - Linkwitz Orion dipole, too. I would probably commission three cabinets, because the TCS corrects three woofers and I could probably get away with three ~14" cubes (~ 7" x 14" x 28" rectangles would be even better, if sonically it would be a wash), which should give me 35L of airspace after 1" thick walls and bracing. (Right now I'm running the front and rear subs through their own inputs, and jumping the two side subs together. Not ideal but it works pretty well.) I already have two of those woofers in the ML Monolith III's (not going with me) I use in my sunroom, but they're not hooked up the TCS and they're in sealed enclosures. They work much better than the stock ML woofers there, but the ESL panels lower resolution and thus much easier to keep up with than the active Genelecs (going with me) in the main system. Also, honestly it is much easier to ask than to try to move the Monoliths to my living room and calibrate the TCS to use them.

Actually, Genelec 1037's and Paradigm Servo-15 subs in the main system, Martin-Logan Monolith III's upgraded in the bottom with the drive-units Genelec uses in their subwoofers in the sunroom. (The Monoliths were, believe it or not, a thrift store find!) Before I address some of the comments others made, some things I should have put in the first post. My audio philosophy in general, which is quite different from, say, the one that drove the equipment list drizzt posted. I'm willing to spend silly money on stuff that makes verifiable audible difference (speakers that employ active drive with crossovers at line level and a separate amps for each driver, room correction, great recordings, a well set-up vinyl rig) but I cheap out on stuff that has never been proven scientifically (in a level-matched, double-blind subjective listening comparison) to make a difference, such as digital sources, standalone amplifiers, and wiring. And I don't waste my time with dumbass "tweeks" like painting my CDs with green pens or suspending my cables on little stands. I couldn't even tell you who made the wires I'm using, though I can tell you that they're the technically superior XLR balanced type and not unbalanced RCA like most of the output of the wire con game. I listen to everything in multichannel, because with a well set-up system using good equipment multichannel simply provides a more deeply textured, broader soundstage. More like a real performance than stereo. Contrary to what one might think, multiple subs are not used for more "chest thumping" or what have you. (Well, they can be, if they're stacked atop one another. But I don't do that. For sheet output, one good sub is certainly enough for most rooms! And as shown in this study with good data and flawed conclusions, leads to greater output in the lowest octave.) One employs multiple subs at different spots around the room to get cleaner bass over a larger area, ironically losing some of the extreme low end in the process due to cancellations and other effects beyond my pay grade. To read more on this subject, check out the well-known Welti powerpoint or read Geddes. The reason wide area coverage is critically important to me (in bass and everywhere else in the audio spectrum) is that I rarely sit in one place for long, unless I'm working or dicking around on the internet. Also, it's kind of shitty to invite guests to watch something and then give them seats with lumpy bass, or to pay all that money for good gear only to give up the good seat and endure lumpy bass oneself. My current home office system uses a single subwoofer, which is fine because I don't move outside of a three-square foot box when I'm at my desk. Beyond those general points: First, by DIY I really mean "take a design off the web like that Peerless one I linked to above and commission a cabinet for three of them." So maybe the appropriate word wasn't "DIY" but "bespoke." Second, the reason the four Paradigms are going to be held in abeyance for a few years (or simply sold) is that she doesn't want to look at them. They're four big black cubes. Actually, it is even worse than that. Three big black cubes, and one with some vaguely tacky-looking veneer on it. (I bought all four used.) And if she won't accept those, there's no way in hell I'd consider asking her to bring in even one oversized black tube sock a la SVS into the room! The Hsu also has issues, and frankly considering that the woofers Genelec uses in their subs alone cost $200 I doubt that a $350 complete subwoofer would keep up with my mains.* in any respect. (And for the record, a 10" woofer will never reach 20Hz except with insane levels of distortion that will certainly be audible compared to a cleaner sub. It simply requires too much throw. Even the expensive REL's are pretty sad in the extreme LF. As are my Genelec 1037's, which employ 12" woofers.) The only commercial subwoofer I've seen (which means viewed the website, not actually seen) that looks like it might work is the M-Design Bella 1200, but with the move and tuition paying ~$10k for unproven subwoofers is the last thing that's in the cards. M-Design also seems connected to Monster Cable somehow. That leads me to think that their products might be very expensive frauds. However, I might take pictures of those to a couple cabinet-makers and see if I can't get something similar made. Maybe more angular, but that basic idea of furniture that just happens to contain a subwoofer inside. Third, the living room in her flat is actually a bit bigger than my living room here. It's a much bigger place than one would expect for an attorney in her first year out of law school; she grew up in it and her parents gave it to her when they retreated to the 'burbs in retirement. The living room is kind of in the middle of the place, but floors/ceiling are shared. It has high ceilings, I don't think quite 2 stories but at least 12' and maybe 15'. Fourth, I think that as long as the subs are clean by themselves the TacT TCS with an appropriate amount of fine-tuning (lots) will take care of setup issues such as integration with the mains. The TCS probably the coolest single piece of audio electronics I've ever seen, in terms of what it can do. Pricey, perhaps, but incredibly worth it. And pretty unique. DEQX also has a neat system, but to work in a multichannel system you need like four of their processors. That makes it both considerably uglier and more expensive than the TacT TCS. I've been looking at various audio/HT fora (AVS, which seems to be a cult of half-wits and mindless sycophants; HTGuide, which seems far more intelligent; audioasylum, which has some great stuff but also so much idiocy that it's hard to find the gems, and hometheatertalk.com, which is probably the best of the lot) since I posted here. It wasn't of much use. In general, few audio/HT forum regulars seem to share my sonic priorities, being more interested in scenes in movies I've never seen than music. (Or stupid mythology like the "sound" of amps or wires.) I didn't find much mention of the Peerless XLS woofers I was considering. The big names everybody seems to go ga-ga over are SoundSplinter, Dayton, Rythmik Audio, and TC Sounds, along with Peerless in htgude.com. (Of those, I'd only heard of Dayton before; I use two of their amps to drive the woofers in my Monoliths.) However, nobody who recommends those drivers except for the Peerless and Rythmik Audio seems to use good main speakers, let alone anything with the resolving power of the Genelec monitors. The Rythmik kits look cool because they're servo subs, though their servo system doesn't seem to be as sophisticated as Paradigm's or Velodyne's, and they're not much more expensive than the Peerless woofers, so that's another option I'm considering. Has anyone used Rythmik gear? So I wonder if those other woofers would be slower or otherwise integrate poorly compared to the drivers Genelec use in their own subwoofers. I also note that Siegfried Linkwitz likes and uses the Peerless woofers in his Orions and Thor subwoofer, which is a very strong endorsement. (Andre, you run his Orions, don't you?) On the plus side, lots of people seem to think that box shape is unimportant, which I'd like to believe, but if that is true why don't companies sell tall, thin subwoofers that can hug the wall? That seems to me to be more room-friendly than a giant cube. Linkwitz seems to attach some importance to shape, though. *Well, probably. Keeping the LCR Genelecs 1037's isn't a hard sell because she loves the way they sound and, well, because I gotta win some battles, too. I am downsizing the system from 7.4- to probably 5.3- channel, but honestly I'm not sure I noticed any real improvement to the scope or texture of the soundstage when I added the surround back channels anyway. And they were expensive. But while that's the more likely scenario it may not end up being the case. One of my colleagues has been looking for Genelec 1037's on the used market since he first heard mine, but since nobody gives up these speakers willingly he's been unsuccessful. (Even I, a congential cheapskate, was forced to break down and paid close to full freight for new ones.) He propositioned me with an offer for my whole speaker setup that is pretty fair. (I'd lose only about 3% of what I've invested in the seven Genelec speakers and the four Paradigm subs, though some of that is because I got incredibly lucky used buys on two of the subs.) There is a fairly local speaker company called Danley Sound Labs that makes a very interesting speaker that can be mounted directly on walls, the SH-100. They don't extend quite as low as I'd like, but I think they could be turned into some interesting pop-art if bought unfinished. (The Danley subwoofers are incredible, too, but huge and ugly.) I've e-mailed and talked to their designer a few times (he was not present when I visited the factory) and he seems to be one of those rare people in "high end" audio who has more in common with scientists than with infomercial diet hawkers. He also offers a powered version, because who wants a bunch of passive caps, coils, and resistors choking the sound? I've worked out an arrangement with them to try out three of them early this summer. I also plan to pay a visit to another local distributor, Jim Smith, to audition the Avantgarde Solos. I visited him before I bought my current speakers to audition the Avantgarde Duos, but they were clearly inferior-sounding and much more expensive. Their Solo, a coaxial design like the ALTECs that got me started in "high end" audio to begin with, and actively driven to boot, look like they might have potential. (Until I heard the Genelecs, I had not heard a better speaker than the 15" ALTEC coaxes - I never took them out to see if they were AlNiCo 604's or ceramic-ferrite 605's, but they had the cell-less "Mantaray" horns so they were relatively late models - fortuitously pre-installed in the walls of my old Boston house. They also look cool. In the small (I think) chance that one of those choices provide most of what I love about my current speakers in a more compact package, I'll be happy to not have to cart 300lbs worth of front speaker away with me.