Subs hit constantly while car is running

[benmattes]

Subs hit constantly while car is running but they play normally while it’s not but cut out after a bit. They also hit hard while breaking not sure where to start

They worked fine for about a month or two
2011 mailbu

2 12 skar evl
4000 watt hifonics amp

 

[SHO'NUFF]

Most likely your ground. I've seen that happen, the sub looks like it's playing a 5 Hz note. If one piece of equipment doesn't have a good ground this can happen.

Check all your grounds, even the head unit. Try to keep the grounds as short as possible, scrape off more paint than you think you need too. Get down to the bare metal.