My friend installed a new alpine headunit for me, the sound of speakers is noteceably weaker than before, and today i noticed that the sub in the back does not work, so all the speakers work find but without the sub it sound cheap. What is the problem? Anyone can help? THANK YOU

 

Probably forgot to hook up the amp turn on wire.

 

Is there even signal going to the factory amp ?

 

When installing a aftermarket headunit you lose factory sub, steering wheel controls and Navi voice.


If you're referring to the factory sub you need to check the DIY, FAQ and Info thread at the top of the page. If it's a aftermarket amp and sub see the two posts above mine.