Quoted from tdiddy:I need one too. I saw walmart had a Sony one on sale for 99.99. But wasn't sure how good it is. http://mobile.walmart.com/ip/Sony-SA-W2500-10-Powered-Subwoofer/12687958?type=shop-by-department
I've got two of those Sony subs - bought them years ago. One is on MET and the other is on TAF. Great sounding sub. I have no experience with the Polk subs but if they go on sale again for $70 shipped, I may buy a couple.