The "pop" that you hear when turning off the system is caused be the amp not shutting down clean. This can be caused by several things -like a poorly designed or built amp. It can be caused by a poor chassis ground cable, poor line voltage coming into the amp, or a malfunctioning amp (if it didn't used to do this before). It may also be caused by the line-out signal coming from the head unit. If the head unit has a problem with the pre-amp section and sends the "pop" signal to the amp, the amp will just do what it's told to.
I would recommend starting with making sure that you have a solid power and ground connection from the battery and to the chassis. Next, I would try turning down the amp's gain if it's set too high and see if that helps.
Answers & Comments
The "pop" that you hear when turning off the system is caused be the amp not shutting down clean. This can be caused by several things -like a poorly designed or built amp. It can be caused by a poor chassis ground cable, poor line voltage coming into the amp, or a malfunctioning amp (if it didn't used to do this before). It may also be caused by the line-out signal coming from the head unit. If the head unit has a problem with the pre-amp section and sends the "pop" signal to the amp, the amp will just do what it's told to.
I would recommend starting with making sure that you have a solid power and ground connection from the battery and to the chassis. Next, I would try turning down the amp's gain if it's set too high and see if that helps.