Hey guys. My JBL PB12 has gone to crap. The AMP seems to turn on and off real fast at lower volumes. If I crank it up it stays on every now and then. It never did it before so I'm already planning its replacement. The room it will be in is 22'L x 12'w x 8'H . I'm looking at possibly SVS subs but not sure what size to get. Also what other brands too look at. Any help would be greatly appreciated.