My father just built a stereo guitar cabinet with 2 Alpha 8A's and two KSN1005A's per side, all in parallel. We is running it with a (30W/ch at 8 ohms) guitar head. The piezo's chirp at moderate to loud volumes. I've isolated it to the back emf problem... it doesn't happen with the woofers out of the circuit.Is there anyway to fix this besides having two amps? I tried a few quick things with resistors and caps I had laying around... but nothing worked. I do have some of the cheap CTS knockoff piezo and they distort horribly at moderate to loud volumes and also chirp just as much.
Would a zobel help?