Factors considered so far include price, SPL output, extension, cabinet size ... anyone thinking about which might have lower acoustic distortion at various output levels? It's not a spec most manufacturers post for any loudspeaker.

That is an excellent point - like any speaker, a sub is more than the sum of its cataloged specs.

Well, this sub is going to be connected to my Outlaw 950's LFE Out...my 3 fronts (DefTech BP7002 and CLR2500) all contain built-in powered subs, and I am running them "Large" in the Outlaw. The Side Surrounds (also set to "Large") are going Speaker Level In to the Polk PSW110 and Out to a pair of DefTech BP2X'...for Rear Surrounds , same thing, set to "Large", in via Speaker Level In on a Polk PSW110, and Speaker Level Out, to BP2X'. It rocks pretty good in 7 Stereo and for Movies I'm rather impressed with the output with my current configuration...but I just bet adding a SuperCube Reference to the LFE Out will make a world of difference while watching movies...I'm just wondering what I'll give up in the 7 Stereo mode....

What physical size sub would quality as "too big" for your space? Both of the subs you've been looking at are on the smaller end of the scale. Also, what do you want from the sub as far as bass response and how large is the room? There are an assortment of folks around here who could probably offer some useful first-hand experience about different subs with that kind of information.

Physically, I don't think there IS such a thing as 'too big', as long as it fits fashionably...but the diminutive size of the SuperCube Ref is a size I would like to stay close to...even an SVS tube would do the trick...the room is 20 X 12, with 10' vaulted ceiling and open on one side to the kitchen, with a doorwall on the other side...I have no WAF to worry about, so it's all about performance...bang for the buck, ya know? Since I have all DefTech's now, I thought the Reference would be what most 'matches' my set-up...but if I could afford it, I'd go with a Trinity....I don't think there is such a thing as 'too much' bass...as long as it's crisp, clean, not boomy, and the higher the SPL the better. If I broke some windows in the process of finding out how high I should turn it up, that'd be OK with me. My local guy will sell me a NIB SuperCube Reference for $1,600 out the door...but if I can get the same performance for less, I'm all for that! What might you suggest?

I don't see a need to match subs to other speakers usually, unless you are trying to match the finishes (as with veneered speakers, for example).

Having owned the smallest SVS tube, it's anything but diminuitive - my wife far preferred the LFM-1 to the 25-31PCi for appearance because of this, even though the LFM-1 takes a little more floor space. If something that takes up as much as 24"x24" of floor space is an option worth considering, I'd say that there are a lot of good options out there.

Size be damned...I'm more interested in performance the higher the SPL at the lower the frequency, the better....suggestions? Ideally, I'd like to test listen, but given my location, I have to trust in others, such as yourself....

There are many good subs out there, most of which I have little or no experience with, but I can toss out a few models or manufacturers that I see come up fairly regularly. On the internet-direct side of things, you have the Outlaw Audio LFM-1 EX, HSU Research VTF-2 or VTF-3, AV123's MFW-15 (which has experienced back-order issues until very recently), and an assortment of offerings from SVS. I've also seen a lot of talk about the JL Audio Fathom units lately.

I've probably left out several good subs for each one I've listed above, but it may help give you some ideas. Others here can probably offer some other ideas - might even be useful to skim through posts in the "Your System Saloon" area to see what others are using.

I broke down and ordered the DefTech SuperCube Reference....AV123, Outlaw Audio, etc. are just making it too difficult to get cuz of shipping, but I found my local dealer has a store on St. Martin that is authorized DefTech dealer (I bought my 3 fronts from them), so I went ahead and ordered the Reference....got it for $1,500 delivered, when it retails for $1,899 without delivery, which is not bad, especially being way out here in the Caribbean. The Ref is supposed to be equivalent in output to FOUR SuperCube 1's....along with the built in subs and amps in my mains and Center channel, and the two Polk PSW10 that I am using for the low end on my side and rear surrounds, I think the Reference is going to round it out nicely...Gee, does that mean I'll be running a 7.6???

OK...now for a new problem....the new sub is not here yet, but I was playing with some Woon Bass Shakers and I found that there is NO output from my "Sub Out" RCA...I didn't select a X.1 Source yet, as it was late, but the "Auto On" feature of the amp I was going to use signaled me to the problem. When I turned the amp 'On', the light was Yellow...then, after 5 or ten minutes, it turned to Red, even tho I was still playing music from my PS3...checked all connections, and everything is hooked up properly...double-checked my 950's setting to be sure Sub is "On", all speakers set to "Large" (each channel has a powered sub, speaker level in, to handle the lows), with all X-overs at 40Hz)...but still no output? What am I missing here?