Stereo upgrade, no sound during phone call
 

Hey all!

I just picked up an 02 Boxster S last week, and decided to upgrade the radio. I ordered a Sony head unit (DSX-A415BT) from crutchfield, which came with the factory adapters so I didn't have to cut anything (except the stupid alarm wire..).

Anyway, the stereo sounds great and works with my iPhone, via USB or blutooth. However, when I try and use the hands free phone feature, there is no sound. Through trial/error I noticed if I disconnect the front RCA cables on the back of the deck and move them to the amp/sub RCA spots, the phone call can be heard (low volume) but then the music sounds like bass. At this point its music or phone calls. Crutchfield doesn't seem to know.

Is this a factory amp issue? Thanks in advance!