Aftermarket system? Installed by Best Buy? Sounds like a crappy installation
If you are comfortable DIYing, I would check the connections at the back of the HU first - since you say both speakers go off at the same time.
I don't recommend going back to Best Buy to have them potentially screw something else up. But if they'll fix it for free, that may be a good option for you. I would try to find a local audio shop recommended by someone with direct experience. It may cost more money to have them fix it, but you'll have peace of mind knowing things are done right. Just my
I'm no audio expert, but I have a fair amount of consumer experience
Forum member bigaudiofanat is in NJ. He is the resident audio demi-god. He works on lots of forum member's cars and could probably do the work for you
