Need Help with Subwoofer Choice

Hi, all. I purchased a Rythmik L12 subwoofer earlier this month. I use it for a music only 2 channel set up. Typically, volume is at 1:00, phase delay is at zero, and crossover is at 50-55Hz. I have not run this unit hard at all. The L12 had worked fine until it failed tonight.  All of a sudden, hardly any sound came out of it, and I only was able get a bit of sound if I turned both the cross-over and volume up, which is not my preference. I am returning it as I'm within the 45 day audition period. 

So, now, I'm looking for another sub for my 9x10x8 room which is treated with corner traps, bass traps, etc., from GIK. I don't feel comfortable purchasing another sub from Rythmik, and I wonder whether subs from other manufacturers who build them in the Far East consist primarily of really cheap components. JL Audio would be great (USA made), but they are very expensive. I think a 12" sub would be a minimum size, but I'm open to suggestions. Your help and advice would be very much appreciated. Thanks.