Here is my current audio equipment: Harman Kardon AVR310 Acoustic Research S50 mains Acoustic Research S20 surrounds Acoustic Research AR-4C center Sony SA-WM40 sub Would a 5ch amp be worth the money?? My system goes loud enough, but what about sound quality? Would I see much gain in that area?? I have also noticed that I prefer to listen to music in one of the following formats: no surround (just the two mains), prologic, 3-ch stereo. Does the 5ch stereo suck just because there isn't enough power?? I've also noticed that in all formats except the above 3, the sub doesn't put out as much as I'd like. THat's why I use the above three formats. DD 5.1 & DTS already sound just grand. If anyone has advice or information for me..please feel free to share!! I'd appreciate amp recommendations as well (please include appx. price!). My current budget would be ~$500, but of course I can save up and get something better within a half year or so. Thanks for your time!