OK so i just bought a Sony STR-K870P Digital Audio/Video Control Center Digital Cinema Sound/Discrete 6ch Amplifier out of a pawn shop and i only have two speakers that run through it they're MTX AAL 1540 250 watts 40Hz-22kHz speakers with 15" subs and i am getting almost no bass out of them. I had them running through a nice Kenwood amp that my buddy let me use and they were about 10x louder on that with the volume 1/4 up. Now i cant even feel the bass at full volume on this Sony amp. I have no manual and I've never owned a Sony amp so i'm lost in all the settings and i just don't know the proper way to connect everything for the best sound and bass. Any help would be great.