Sub for 21 x 17 room for music only

You will have no problem with any of your choices.

Try to aim for a Sub that can be set to the point where you main speakers drop off at.If the roll off is 40Hz. try to get one that can be set at that level.

Also aim for one that can go closest to 20Hz.

Why anyone would want a sub that only goes to 35Hz. really puzzles me.

Try to get a REL or SVS.

Happy hunting!

take a look at vmps also-they are very musical and fast.

Check out audio concepts at www.audioc.com. You can not beat their product. The Force should be plenty for your room.