Loud Bass Noise When Car Turns On/Off

Hello, my Rockford Fosgate P300-10 when the Auto Turn On is set to auto there is a loud bass noise when I turn off my car, but when it is set to DC 12v there is a loud bass noise when I start the car. I drive a 2013 Honda Accord Sport with a stock stereo. We spliced the back speakers’ wire and connected the sub to the splice wire. We also noticed the when the sub is set on auto will power on if we move the sub. Do you have any idea what could be causing the noise? P.S. I did not use a remote wire because I was depending on auto power.iwillett

My recommendation is to connect the amp turn on lead and see if that cures the issue. Just connect to an accessory wire in the vehicle. I'm not a fan of auto turn-on.My ex once told me I have a perfect face for radio.

Does it play normal once it comes on? Or does it always make non musical noises? Above the rear seat, dead center of the vehicle about 4 inches forward of the rear glass, is there a microphone in the headliner? If it does not have microphone in the headliner, open the trunk and see if the noise goes away. If it does, tap into the front speaker wires instead of the rear, guaranteed to eliminate the noise.

it may be the ANC ( active noise cancelling ) that comes on newer Hondas.    not 100% if the 13 accord has it but it should , my 10 & 12 pilot and 17 crv have it.   it is a box that uses a mic in the cabin to sense road noise and will make sound through the speaker to compensate.      https://www.hondaaccordforum.com/forum/audio-visual-electronics-10/2013-2014-accord-anc-disable-pictures-52838/page2/