Problems with headunit and speakers please help!

[2006 Scion Tc Flint]

ok so i had a avic f 700bt and took it out and put the stock radio back in the car, a local audio shop did it and now when i turn up the music to just enough to hear it good with windows down or up it will make something like a pop every now and then but when i turn the music down it will stop. I also had to 12" subs and those are out. I don't think the speakers are blown

[O5_TRD_tC]

hmm did you check for loose connections?

[navylife59]

When the aftermarket gear was installed, did they cut and splice the wiring? Does it matter what source you are using for the pops? Do you get any alternator whine? Do you have HIDs? Was the stock radio stored in a dry location? Does the sound emanate from all speakers? Do you have OEM sub? This used to be my field of expertise back in the mid 90's when I worked for Metra Electronics.