Decent Amp.. Terrible Customer Service.. Remember.. This amp is 2 x 4 channel.. It senses the additional 2 channels and becomes a 4 channel when it sees signal on the other RCA’s. Something Customer Service could not answer for me. Had to figure it out for myself or send the amp back. I thought there was something wrong with it at first. But it is auto Sensing for the additional 2 channels.. Quiet Amp that makes good power !! I think SSL uses a call center for handling calls from customers. Just a guess.. If Customer service were better, I would have given them 5 Stars !!