I just completed (no finish yet) and installed a new sub so I thought I'd post some randomness. It's a 17.5" cube (16" internal) made of 3/4" marine-grade plywood and 2x2 bracing, just glue and clamp butt joint construction. It uses the 12" Dayton DVC woofer from Parts Express on the front and two Lambda 15" 15PR1400 1400 gram passive radiators (purchased as B-stock) mounted opposing each other on the right and left sides. With the 64L net Vb, Fb should be around 23-24 Hz moderately stuffed. Here are some FR numbers taken at the listening position while the sub is in my "sub-corner" in the front of the room about 11' away. Amp is an Adire AVA250, readings are "corrected" Radio Shack SPL meter, and this is with the DVD player connected directly to the sub amp and the crossover maxed: 100Hz - 78.0dB 80Hz - 78.5dB 63Hz - 84.5dB 50Hz - 85.5dB 40Hz - 84.5dB 31Hz - 83.0dB 25Hz - 82.0dB 20Hz - 78.5dB This is a randomly chosen level, not maxed (homey don't play that). The room is 12'x13'x9'H, so maybe someone can tell me what's a room peak and what's not. Any peaks don't appear nearly as severe as I've measured with other subs in ths corner, I can't imagine why this is the case (the PR's are basically bi-polar?). Since many people apparently use subs for movie watching and music listening as opposed to just test tones (go figure), I did run a bit of each through it. It's a stellar performer as a HT sub, really putting out with nary a whimper @ 10dB below reference (75db using Avia)on the usual demanding scenes from The Haunting, TPM, Saving Private Ryan, although that THX intro from TPM did bottom the driver (the first and only time) at this level (backing off 2db solved that). (EDIT: I realized that I actually had the sub a little "hot" during those scenes. That, in combination with the RS meter's 2-3db reduced sensitivity with LF pink noise [which I didn't account for,of course] means that the sub was actually more like 5db below reference when it bottomed on the THX intro, not 10dB.)I actually wasn't surprised at this due to the sub's fairly high tuning. During some of these, I measured peaks of over 110db from my seat. Music was also quite nice, with the sub having a full quality that works well with stuff like the new U2, Pink Floyd...bass guitar/drum stuff. It doesn't compete in extension or quality with a dual-Tempest IB, but it's not what I'd call "one-note". I plan on making a plywood circle to replace one of the PR's with. This would change the tuning to under 17Hz at the expense of output, but it might be interesting having the two options. I'll try and get some pics up after it's finished.