Subwoofer for 2.1 setup with focus on music (1 Viewer)

I currently have a 2.1 setup with no subwoofer. The breakdown between movies & music is 40%movies and 60%music.

My current setup
Receiver: Marantz 1501
Front speakers: Polk RTi8
Room dimensions: 16 x 10 x 12

I am on a very strict budged with around $320 to spend tops on a subwoofer. I don't expect the sub to work musical wonders but want the best musical option in that price range. A clean and tight punch with focus on music is what I am looking for and not necessarily a sub that can shake the walls and knock off picture frames.

So I looked at the BIC-12, PL-200, Polk PSW505, PSW111, PSW125, Klipsch 12HG, and of course the HSU STF-2. The STF-2 would be my top pick, but since this sub is outside of my price range ($400 out the door), I have to settle for a different option. Based on my research, the PL-200 attracted me the most as the best sound for the money, but I don't see that it receives much praise for its musical ability. The Polk PSW111 came next along with the PSW505 in that they do better musically than the other subs mentioned above. Your advice and input will be very much appreciated.

HSU STF-2 Skip the Polk subs like the plague IMO.

I agree with John on both counts. (I have the STF-1 and STF-2 and love them both, but the -1 would be too small fo that size rooms. I also tried a Polk sub early on and had to send it back, it was terrible.)

So I pulled the plug and bought the NXG NX-BAS-500 from RadioShack, a sub I overlooked somehow while doing research. After reading the few but very reliable reviews on this make and model, I feel that this sub will produce the sound I am looking for at this price range. Should be at my door next week.