i pick up a 500w alpine 10" sub and a 90wrms 2 channel alpine amp and i found some 12 gauge power wire lying around, just wondering if that would power my amp correctly.
Yeah, it'll be OK not great but OK. Ideally you would use 8guage purely because if you want to upgrade you can without having to replace the power cable again. But, if you've got it laying around....then use it.