amp in a mazda 3 with bose, noise

Just installed an amp in a mazda 3 with bose. when i cut off the system the subs make a loud feedback noise. kicker amp and sub installed from inline converter. signal caught before you get to the rear door speakers. any help would be appreciated to figure this out.

thanks

If you open all of the doors of the car, does it still happen?  The problem is the amp is remaining on when the radio is turned off.   Where did you connect the amp's remote wire?  Since it has a bose amplifier, there should be an amp turn on wire that turns that amp on.  If you find the amp you should be able to use a meter and find the wire that has 12 volts on it when the radio is turned on.  If you tap into that wire you will no longer have this problem.

No idea where the amp is, but the wire should also be on the back of the radio.   If you install the line out converter behind the radio it should help this problem.  The reason it is happening is the speaker in the rear door is moving slightly, when a speaker moves, it produces voltage.  The voltage in turn sends a signal to the sub amp and this makes the sub move, in turn moving the door speaker again.  It is an endless cycle.  Moving the LOC to the back of the radio will probably take care of this problem.