I also have a 500/1, and that is a VERY underrated 500. I know for a fact that it will put out ATLEAST 650watts on 13.8 volts, however the amp cuts off at 8-9volts, but will never drop BELOW 500watts. I could have got a PG tantrum 1200.1 for cheaper than i got my 500/1, but i know, and love JLs quality, amps especially.