So im using a PA poweramp Qsc RMX series (not sure the exact model yet, still need to pick it up from my friend) but I know that the max for a jbl is 300watts, and im pretty sure that's with a closed back, im using an open 1x12. But I don't want to blow the jbl, im a little confused with the whole power thing, I see a power amp could be .. Lets say.. 450 watts, would running that to the jbl blow it or do something bad even at low volume?
I think you should be fine. It's better to have too much power and run clean than not enough power and run into clipping. If you start hearing weird things, turn down. At low volumes you should be totally OK.