Sound system trouble

This may have been covered in anoth3er thread but I couldn't find it... I have an aftermarket sound system and the speakers go in and out with bumps and switch sides that is playing on turns and what not. Before I get the guys to come take a look I wanted to get some ideas on what it could be. Thanks in advance guys

Loose connection somewhere.

yep. check all connections first. then check equipment

Thanks for the fast responses guys. I will get on that first thing tomorrow