Speaker Issues

Ok, last night my friends and I were putting speakers in my 1982 Crown Victoria LTD again. Well, about a month before these boys had put in 2 new 4" Pioneer speakers in the front dashboard. The next morning I was driving to class and the speakers were buzzing, but only when the songs had any bass in them. I kept telling these two that they were buzzing but they didn't believe me until last night. Now instead of just the front two speakers buzzing, the back are doing it as well. We can't think of what it could be, they think maybe since it's an old car maybe its the wiring, could that possibly be it, or maybe the people who put my CD player in it did something?? If anybody has any idea let me know. Thanks a lot.

It sounds like the voice coils are blown, you may want to try using a test speaker to verify that there is no problem with the signal wires.

Maybe some help..

Good Luck!