new sub for speaker system

[suppal138]

My current setup is a Marantz 8500 with KEF Q5 towers. Used to listen to music only. I wanted to add a sub and was looking at the KEF PSW 3000 which is on sale at UBID for $261.
Other suggestions have included HSU STF 2 and UFW-10 by Onix. They will cost me between 150 and 200 dollars more.
Im new to this.
Any help would be appreciated

 

[MacManNM]

For ~200, you can get the Acoustech H-100 sub, good sub for a good price. Other options are the Cadence XSUB, that can be had for ~240. Either way they are both pretty good units for the money.