This is one of Hifonics best 4-channel amps power is very clean and strong i have it on Alpine Type-R 6/9 and 5 1/4 components by Alpine I have a Kicker crossover so I did not use the amps the amps gain is turned up a little over half way and I can barely stay in the car had a mb quart that I think was defective and sent that back to sonic and purchased this one I have no complaints what so ever the amp reminds me of some of hifonics old stuff it would be a wise decision for anyone to purchase this amp I have been into car audio for over 20 years and with this amp you are getting your moneys worth great amp dont no how long it will last but I think it is a very wwell designed amp will post a new review if anything changes .