2010 HK Non navi where's the voice control

I just got a 2010 gt ltd with the HK non navi. Anyway I have a kenwood double din DVD HU I pulled from my old car that I know with enough money and effort can be installed and even interfaced to the steering wheel control.

HOWEVER the one issue with the kenwood is the mic and therefore voice control/handsfree is terrible, but the builtin in great on the car. Do we know where the handsfree system is? Is it all in the stock head unit?Any way I can keep builtin handsfree and voice, but install my new stereo?

Thanks