i have a alpine 4 channel amp. it was wired to give each speaker (4 interior speakers) 50 watts at 4 ohms. (left front right front and the individual rears) i was wondering if it was safe for the amp to be on different ohm loads per channel? for instance one at 2 ohms while the others are at 4

 

They should all be the same. In that case where its 4ohms still the output will be half as much as it normally should.. make them all 2 or 4 as long as the amp supports 2ohm. some 4 channels do some done. but check the specs not all amps are the way I described so check it out on the specs. What amp is it.

 

Most 4ch amps arent stable at 2 ohms stereo so that wouldnt be a good idea. Most of them are 2 ohm stable but only when bridged to 2ch. Thats just generally a bad idea as the speakers would be getting different power, effecting the overall sound quality as one speaker is gonna be screaming from the added power while the others are gonna be noticeably quieter, assuming your amp could even handle the impedance.