high end subwoofer...which one tho?

You might want to take a look at this review:

http://www.soundstage.com/equipment/paradigm_sub2.htm

I run two JL Audio F113's ...... STELLAR RESULTS !!!

There's lots of good subs out there for sure.
I have been quite curious about the Paradigm sub25.
if you like reviews, a few have put it above the JL Audios.
I haven't heard it,but she's suppose to be the one to beat,
except perhaps the sub2.
Of course that could be debatable.I have a 11X15(with Gik traps)and use 2XDD-15s(for music)I like two better than one as
you can sit anywhere and it's a nice layer for the higher
instruments to dance on,nice and solid.
I do want another just for movies as it saves me reconnecting and adjusting the EQ ect.
even in a small room two is better than one as I and many others have discovered.

I own two F-15 subwoofers from Rythmik Audio with clear, articulate, fast and not flabby results. They're audiophile subwoofers that do extremely well in both two-channel audio listening and home theatre applications. I spent several months researching subwoofers over the Spring and Summer, so I know what you're going through. The questions seem endless...

1. Driver size?
2. Room volume?
3. Ported vs. non-ported vs. TL
4. Amp power... what is too much or too little?
5. Cost considerations... best bang for buck.
6. Build quality and reputation?
7. Audiophile or Godzilla foundation smashers?

I chose Rythmik Audio after talked to representatives from all the usual suspects. I'm very pleased with the F-15's.

Im running a Fathom 112 (single) and love it, but..... I auditioned several others and for HT use IMO most of the high end units will work beautifully. I chose mine based on 2 channel use (I thought it was better controlled, other opinions may vary. For HT use I'd be happy with anything mentioned on this thread. if your house and budget can take it the new paradigm 25 looks pretty dangerous!

Rel Studio

Velodyne DD18

JL Audio f113

.
...forget about the Velodyne DD-18 as someone suggested here. It is waaay to much overkill for a room your size.
.

If price isn't an object (nor is floor weight), check out the new Paradigm Sub Two. It has six speakers and something like 3400 watts from its amp. The initial reviews are amazing. They have apparently aimed right at the high end REL and Fathom buyer.

I use Rythmik subs, but for a dedicated HT set-up, I'd probably choose SVS. Disclaimer - I use a pair of 12" Rythmiks (not 15" which are probably more suitable for HT use). Also note that my comments are based on comparison of the performance test data I used to choose the Rythmiks, NOT on any actual listening session comparing the two brands.

The test data were useful because they illustrate the difference in the design priorities between Rythmik and SVS. In a nutshell, SVS optimizes sub bass and Rythmik deep bass. For reference purposes, in a 12" model, the SVS start to pull away below app. 35hz (anechoic).

The Rythmiks allow maximum control over the driver's damping and this allows a lot of flexibility in optimizing the match to mains for music. The design trade off (vs. a similarly priced SVS unit) is that there's a bit less clean SPL capability, which may well be audible on an the sub bass info in an effects track (though it's very unlikely to ever be a problem for music). I would (and did) prioritize the former for my 2 channel music only system, but I'd go with the latter for HT use.

Again, YMMV.

Good Luck

Marty

One quick additional thought:

In a smallish room, you're not going to need a monster sub - and a 15" model from any of the brands that have been recommended here will likely provide crushing bass capability in your room. The 12" SVS cylinder is probably more than enough.

As Bob pointed out, the addition of DRC (like the Audyssey chip included in many HT receivers and pre-pros) will almost certainly be extremely beneficial to bass performance in your space. The difference between DRC/no DRC will likely dwarf the difference between choosing the best sub versus choosing a merely good sub.

Marty

My rythmik 12" seamlessly integrates with my paradigm signature S2 bookselves. My crossover is at 100hz. This sub will be as transparent as any other sub out there, at any price. The only thing to consider is the headroom. I believe the JL will play louder. My room is 20X20 and the sub fills the room for both HT and 2 channel. It is one of the great bargains in audio. I sent back several subs before settling on rythmik.

The Submersive by Mark Seaton is very good. There are upgrade finishes also available.

Will

you can't go wrong with any of those brands

i still say the old velodyne ULD series are some of the best subwoofers ever made. pretty cheap on the used market...if you can find one.

I guess when you say hi end sub do you mean hi end for 3-5k? Or less? Or more? :)

1k? = REL T1 It's increadible... you may not need to look futher? Slam reliablity, fun, easy to set up... and some how intergrates into any system? How? You say? Long answer but worth finding out.

3k ish = REL Brittania B1 (I'd get two of them... rel prefers 3 per room... they come set up for an amazing way to to divide all three)

4k = Thiel SS2 (Use two...) Well yes it's on the audiphile level of sub, but the fact that your loins will shake while ever so gently tickeling your ears like some one put a feather in it isn't so bad either.

I actually really enjoy the Theil SS3 Sub. Although it's no longer made it will almost pick up your house and walk away with it. But for a budget just get 2-3 rels (t series or Brittania Series) and you'll freak anyone who comes to your house and watches U571 (Depth charge scene) to running out of the room and crying like a baby in fear.

I just might do that right now... My neighbors dog keeps barking..

Like a good que butt can be used with both a snooker and straight pool shafts a good sub can be used for both two and multi channel systems. Today it's setup and EQ that intergrates any sub into the room. IMO JL and Velodyne will make this a simple task especially if you don't have room correction, and also provide the ability for truly deep output. This same EQ will allow any size sub to be used even in a small room, not that you need it though. I use a Meuci Power Piston and two Velodyne DD10's.

I like the Revel B15. I run two B15s and they are front firing. In a small room one would be fine. I had a HSU Research big guy, but it was down firing and caused my wood floor to rattle. I do not have that problem with the front firing B15s and the position in the room was the same for both subs.

That's a small room for now and you would not 'need' the formentioned however it would be useful and work later for a larger room. I would opt for a svs 13...just because of the fact why pay more. Take a look at Elemental Designs (ED) subs as well. Killer performance, killer price, and free shpng for something that weights as much as all your gear put together.

The SuperNova MKIV-12 is terribly insane in performance, with more than 100 decibels of power...it will shake the walls.

I have 2 definitive technology supercube reference subs in a 14 x 22 foot room. These have one 14 inch sub with two 14 in radiators. Internal amp 1800 watts. They are awesome for two channel and HT. cost $1900 each.

I own 3 Velodye Subwoofers, and I could not be more pleased.
Never ANY issues with any of them, they integrate very well.

Maybe not the $$$$$ The most expenxive but, IMHO with the right power cord,
and interconnects, proper placement, they are VERY hard
to beat.

At 12hz. I don't feel like I am missing anything.

Fast, tight, DEEP, extended Bass, with little or Zero Distortion, unlike other "huffers".

Both music, and movies, are played with tremendous
clarity, and dynamics.

I use a 1 18" and 2 15" and once calibrated for the room,
it is true, multiple subs. do "smooth" out the bass,

It's NOT about more Bass! But, cleaner, tighter, faster,

Bass!

It is the same as implementing mono-blocks, multiple

sub-woofers take the load off the single unit; Allowing
it to play without ANY strain, cleanly and deeply as
they are intended to play.

I LOVE MY MUSIC!

I vote for Aerial SW12 or Audio Physic Rhea 2. The Aerial is most powerful, but the AP Rhea2 a bit more tight and dynamic. Above these you have the Burmester S8. It costs a lot, but it is the best sub I know about for music.

JL Audio is also good (almost as good as the above), but be awere of that they lack speaker level input. That´s why I won´t reommend them. When it comes to music it is always best to connect subwoofers to amplifiers using speaker cables instead of interconnects from preamp.
I wouldn´t care about the Velodyne unless you really need the room correction functionality.

Paradigm Servo 15" reference