could anyone give me a basic idea of how many watts i will need from a 4 channel amp to power my main speakers (tweeters, 6 1/2's, and 6x9's) I have all alpine type R speakers, and I have an alpine - 9815 HU, which is 60x4... thanks, and if you dont mind, please reply to Chupacabra2k5@aol.com