Monsoon systems are a pain in the tail. What you have is called a turn off pop. Try this: With the system on, remove the remote lead from the amp and let it turn off while the rest of the system stays on. Does it pop? I'll bet it doesn't, but lets find out for sure. Now try powering the amps turn-on lead from the +12 volt constant, and turn off the car but leave the amp on. I'll bet that's when it pops. This may or may not be an easy fix. Using the LOC with the signal sensing turn on circuit is part of the problem. It's holding the amp on for a time after there is no signal, thus the amp is shutting down after everything else. Try running that to a true accessory wire and see if that helps.