i just recently bought two 10in memphis subs from a friend and have them powered by a 600w sony xplod amp. This is hooked up to a Kenwood MPV7019 head unit. I got them installed at the local best buy due to my 1999 grand prix having bose speakers and that having to all be rewired. After using the subs for a few days i noticed that that subs really weretnt as powerful as i had heard them in my friends car. I tried using the bass controls on the head unit but that did nothing. I was wondering if there was anyway to lower the gain on the amp itself? Any help would be greatly appreciated.