I installed an AVIC-D1 in my 06 F-150 with the Audiophile package. When I power the vehicle from the key the sub pops/whoomps when the head unit enables the subwoofer. It is anoying and I am sure it is not good for the sub. What is causing this? Anyone find a solution? I have looked all over online and I find very little info regarding this other than live with it or the wiring is bad from being ran next to power cables. I know its not bad wiring since I used the Metra adapter for the sub harness and I am using the stock wiring. Do you think the enable signal from the AVIC is too high of a voltage to the enable? I had the same problem with an Expedition with the audiophile using aother type of head unit from Pioneer. Help would be greatly appreciated and would help future modders with similar problems.

 

I'm pretty sure the problem is the voltage. I know for a fact that the Z1 gives out 12V (should be the same for the D1) but ford uses 5V. Hence the reason why it makes that thump/pop sound. Essentially you would need a 5V fixed regulator (7805) from some place like radioshack. Here's a pic.

Edit: found it on Radioshack website

 

I purchased that item.
Installed it and it works perfectly!
Thanks so much.
Just a note, the ground must be used or it will not work.