that problem comes and goes for me. i did a bunch of testing... definitely my amp and not some other configuration/installation

jbl gto75.4

you might have a sheety amp like mine
right now no prob and it sounds good

 

This only happened after I changed the component speakers, so it's definitely something in the doors. My amp (alpine) should be OK.

 

like imadarkrider said... something is definatly grounding out... possibly a pinched wire... this happens.. because a (-) signal being passed through the amplifier on the radio, is causing it to clip and go into protection.... check all connections.. and wiring... make sure nothing is contacting metal... possible fix.... put dynamat on the door before install the speakers... this will help lesson some of the metal near the speakers that may be causing the speakers to ground... even if just 1 speakers is grounding out... all will start to clip