Even when hooking up a relay from the amp output to the relay and delaying the connection for a few seconds, there is a short pop on the speaker after the relay makes the connection. Attached is a pic of the relay part of the amp. How do I eliminate this pop?
When the relay closes, C4 draws charging current through the speaker causing the pop. The solution is to give C4 an alternate charge path. A resistor of a couple of hundred ohms from pin 4 of the relay to ground should do it.