2005 Acura TL Nav Question..please help
 

I just purchased a 2005 TL with Navigation and have a question. When I change the settings to voice guided, the system talks through the front speakers but the rear speakers keep playing music. When I have the radio turned up, it completely drowns out the nav system. Is there a setting I can change so the Nav speaks out of all the speakers or does that sound like a problem I need to have fixed by a professional? Any help is appreciated!