best subwoofer for less than $1000

Im looking at Velodyne and Svs primarily, but if there are any others that are worth while feel free to mention them.
MJ Acoustics, small, fast, musical & reasonably priced.
Jason Scott distributing for U.S. residents.
Used REL comparison for the money IMO
First, several questions to you:
1. Are you going to use the subs mainly for music, for home theater, or both? If mainly for music, what kind of music will you listen to?
2. Do you want a powered sub, or one driven by external amp?
3. What is the low frequency response curve of your main speakers?
4. How large is your listening room?

Used Alon/Nola Thunderbolt. Very fast, tunefull and deep true bass. Fast enough for planars or stats.
Would you consider $1050?

After all of my research and auditioning, I will soon purchase the ACI Titan, although I have not heard one yet. $1050 for the basic model (plus $20 for spikes) with free shipping until Dec. 31.
response to Sdcampbell
*i do 50% music and 50 movies so the sub miust be able to do both well. I own nearly 1000 cds and listen to mos of them in all genres
*I want a powered subwoofer (easier fiddle with for me)
*main speakers are wharfedale opus 2s and go to 30Hz comfortably.
*my room is 28'L by 22'w with 8' ceilings
do it right and you don't need a subwoofer
"Von Schweikert"
Anyone know when the new Hsu HO series is shipping?

I'd take an ACI or HSU over SVS for SQ. But a SVS 1st if SPLs is your concern.
-rel starta III (great intergration) for music
-Sunfire signiture for movies(small footprint and teffifying)
-James sub (good mix for music and movies)

all are about $800 to $1000 used..
How about a Velodyne HGS12 (look for make 2)? I use 2 in my music system and each can be had for around $900 used. Not the last word in sheer output but very nice for the price.