Subwoofer and amp troubles
 

So I installed my subwoofer about 2 months ago, and they worked great for the first month and a half but recently I will your my car on (and not even turn my stereo on) and my subs will start pulsing steadily like there is music coming through even thought everything’s off. It continues to do it when I play music and occasionally it won’t pulse during a song when the bass isn’t playing during the song, any suggestions or help would be greatly appreciated!!!!