"To anyone that has an Polk Psw505 with a blown amp and wants to bring them to life again this review is for you. I have two psw505s with blown amps, after viewing my options was to either buy an oem amps (250 each ) or an external amp. I decided to go with the rockville RPA9 amp to keep the price down. This amp pushes one or two polk subs on the bridged mode. It’s working out for me, I have a sony receiver with sub out connection so the bass is very clear. Down side is that it does not go as low as with the oem amp. Still shakes the house but nothing like the original. Volume is pretty steady until you hear the sub speaker starts to making small popping noise. This speakers are rated at 300rms and 480 peak amps, I know that they are moving well but they will not hit the lows, so if you like the rattle and ground shacking from the original psw505 you will not get that, instead you will get as low as 30hz and clean bass, don’t get me wrong, they hit really good but I am not going to push them until they pop. For this price I just saved two psw505s from trashing them and also saved about $300 dollars. Very simple wiring just get the right banana receiver plugs and banana wires. I spent on amazon $260 dllrs with wires and connectors, you can always drill the box and splice the wires together (save more $$)."

"It's an amplifier, if you don't know what the difference is between gain control and a volume knob is, then you shouldn't be shopping around for one of these or writing bad reviews because you don't understand how it works."

"Pairing this with a pair of sbg1154 and with the crossover turned on and it does a good job of filling in the low end that my rbg12's don't have. Will be testing this whole setup out on my first dj gig soon. Will update later. Only thing I would suggest to rockville would be to add an adjustment for the crossover. Would be nice to not be limited to one set frequency cutoff."