i'd suggest getting a pair, if mainly for music - *every* aspect of subwoofing improves, & *every* possible negative re: integrating w/your main speakers is minimized, when using *two* subs, imho...
i'd suggest, based upon your room size, a pair of vmps original subs, a marchand deluxe xm-9 x-over, and the best used solid-state amp ewe can find/afford. while the cost will exceed $1k, it should still be under $1500, & it will be *really* something! :>)
regards, doug