Rory, the Onkyo sub is being put to good use in my small family room. Very happy with it there. The Polk and KLH are headed for the flea market real soon though. If they don't sell there, I will throw them onto eBay.
VMPS original sub: 12" active megawoofer with 15" passive radiator powered witha bridged Adcom 555...600watts of bassic bass. I just built another sub based on the same design, still applying the finishing touches. Got a Hafler P505 to power that one. 110db@20Hz. My teeth is rattling. LOL
SVS advertises here and a great place to do it. Actually most of us old timers here had our SVS's before they started advertising here. Plus Ron, one of the owners stops by once in awhile to chat which is a great plus. SVS may not be for everybody but it sure will do for probably 90% of folks. You never hear negatives except for things like my room got bigger I need another one or a bigger one. I am sure you could find a perfectly tuned concert director somewhere that may prefer a quieter and what some call more musical sub. I have the PB2+ now the PB12+ and with my set up am perfectly happy with how it handles symphonic music and HT as well. You just need to back off the bass a couple clicks on music is all and your set. No biggie and if they would sell them in stores they probably could sell them for double the cost of what you pay for them over the internet.
DIY 15" Adire Tempest Mid-Q sealed powered by the parts express 250w plate amp into dual voice coils throwing out around 350w I believe.
I'll echo the idea that DIY can rock the house. I cannot turn up the tempest past 1/3 it's potential due to the fact that I live in an apartment complex. I really don't think that you can do any better for less than 400 dollars.
Not great pics, but a couple of theses 12's right now with a Rythmik NS-380 Plate Amp on each.
Amps are set up with no boosting and max extension. With the Pari EQ in line (pic at link), flat in room to around 19-20Hz with "clean" usable output down to 15-16Hz. Output limited by drivers Dumaxed one way linear Xmax-(16.5) & Xsus-(22.5), tho they do get plenty loud. I usually only run one in my aprox 2500cf³ room that has a large 9-ft arched opening that leads/opens to the kitchen, bathroom, & hall, that leads to other rooms. At Ref volume both are needed to keep distortion/harmonics in check, but I seldom listen at that spl level. Usually -10 to -15 under for most movies..
Their a Lower Q design .600
Have many other DIY subs I've built, but these "currently are doing the job and I really prefer them". That compared to, say my 2039PC sonotube Clone using SVS's (first gen driver) and PE-250 Plate amp. The Clone measures so close to a friends Real SVS 2039PC, (both subs measured at his house same location and settings), it's not a factor that it might be a fault of my DIY effort. It (the SVS 2039PC clone) sounds & measures great, so don't take it wrong SVS owners, I just prefer these sealed subs to it, thats all...
Have not heard any of the Ultra driver based subs yet and I'm quite sure they perform amazingly from the reviews and measurements posted..
I appoligize for all of the extra words to mention the Subs I am currently running...:b