or so I suspect.
I have 2 out of 4 channels bridged for my sub and it cuts on and off when I do two things:
1) Drive on very rough surface
2) Adjust the bass Frequency on my deck (not preamp).
I normally set the deck bass to minus 2, but if the sub cuts off and I turn it up to 0 or above it will come back in full.
I checked all RCA and speaker wire connections and even if I play with them while the channel is working it doesn't cut off, so those connections seem fine.