wonky amp...??
 

Hi there, i've got a rf 500bd amp...have been using this amp in it's current configuration for over a year. Just today i get in the car and everything is fine, find the song i like and pump it a little....the amp stops powering the subs all of a sudden.

I've testws it a few times, basically past a certain volume (and sub level) it will stop powering the subs. since it DOES work at low volume levels i'm assuming that it's a voltage issue. Unfortunately i don't know where my voltmeter is so i couldn't confirm my suspicion.

Any ideas?

I agree, It sounds like a voltage issue to me.

could be voltage (car or wiring)
could be a damaged voice coil causing protection once it heats up (sub)
could be a protection circuit being over protective (Amp)
could be a protection circuit working properly (anything... a loose speaker or power wire, a system short

Find your voltmeter...