With your percentage of music, for subs in your price range I'd stick to Hsu Research or av123.com is selling their Onix UFW-10 sealed sub for $400.
The Ascend Acoustics 170SE with the SEAS' tweeters is a nice step up from the original Ascend 170 to my ears.
The Ascend Acoustics 170SE with the SEAS' tweeters is a nice step up from the original Ascend 170 to my ears.