The protection circuit on the left channel of my SDA-1C's shuts down the tweeters at medium volume levels. I swapped the tweeters from the right to the left channel just encase one on the left side was bad and still had the same issue. I also tried a different amplifier to eliminate that possibility and it still shut down at moderate volume levels. Please not the amplifier was no where near clipping at these volume levels.
I looked at the crossover and located what looks like a thermal resistor in the circuit that must be going bad. Does anyone know if these are still available from Polk? I checked their service and parts page and don't see anything listed except the complete crossover. Thanks for any help.