Rear Distortion In new speakers
 

So I have a Kenwood head unit and 4 Polk audio speakers installed in my truck (650 in front, 651s in back).

When I fade to the rear the speakers sound like absolute trash at all volume levels. But, if I switch to 2-Zone and play the rear they sound just as good as the front. What could be causing this and is there any settings I can adjust to make to them better without purchasing any more equipment?

(I don't have a sub or an amp)

What kind of vehicle year and make and are you using a interface module

Its an 08 GMC Canyon Crew Cab. Yea.. Its a Schosce adapter from walmart. Its hit or miss (Grounding issues while its cold) so I bought an axxes one. But I have yet to install it

I originally thought it might just be crappy oem wiring to the rear. But what throws me off is the fact that when the radio is switched to 2 zone the rear speakers play clearly. I feel like this may rule out the adapter also.

I'm not sure how the 2 zone actually runs. the HU is capable of playing both front and back clearly individually. So I assume the HU would have enough power for running them all on the same channel.

BTW the kenwood is a kdcmp438u

Thanks... I really appreciate the guidance

As I am not familiar wth Kenwood audio setup,call them directly to make sure audio menu is setup properly 905-670-7211 and ask for technical . Also since you have the axxes module give that a try.