Here is the problem:
I have a new Alpine deck (about 2 months old to be exact), everything was wired in professionally and rear speakers were also wired into place. Everything was working fine then suddenly all speakers sound muffled and of very low quality. I have checked all connections to the front and rear speakers and they appear to be fine. I check the balance from front right to front left speakers, the sound seems more muffled on the left speaker(driver side). I check the rear speakers and the right rear speaker seems like it’s very low (volume wise). Can anyone diagnose the problem?

 

Check the harness behind the radio. There may be a short somewhere that is causing the speaker amplifier (inside the head unit) to go into protection or something like that.
Professional installation isn't always professional installation. I've known my fair share of audio installers and many of them should never be allowed to touch something with wires on it.

 

I'll check that out, thanks.

 

+1

If you're familiar with a digital multimeter, then you could measure the resistance from each side of the speaker terminal to ground. If you measure some resistance in the kOhms range, I would begin looking for a short somewhere connected to those set of speaker wires.

 

One more thing you could try if it is not an electrical problem is set all your CD player settings back to factory. It most likely will tell you how to do it in the manual or online. Sometimes if your FIE or filter settings are out of whack then the overall sound can end up being pretty unpleasant.

 

have you made any changes to you set up like installing new door speakers or anything like that .

i seen where people have installed speakers or down the road the speaker ground out in the door and will casue this . check and make sure none of you speaker are grounding out in the door frame and deck lid for your rear speaker pretty common thing i have seen . also if you speakers are wired backward meaning +- to -+ on your front speaker and not in the back it will also casue this as well or vise verse . but i would check the harness first like FAB said . just because it was a professional install doesnt mean anything .

to check and see if speakers are hook up wrong fad speaker all the way to the front and see if it get loader if it does then your speaker arent hooked up correctly and try the same to the back . sometimes this will help you out to trace down what wrong .

 

I will try that method, thanks

I've tried that, yet the speakers still turn out muffled

Thanks for the input, I'll keep everyone up to date with it when i can.