All door speakers stopped woring simultaneously, 02 x5 3.0i

[audioissues]

Hello everyone, i'm new here, and have no experience in diagnosing or fixing car audio problems , so I thought this would be an appropriate place to seek help

I drive a 2002 e53 x5 3.0i that I have had since October 2016. When I got the car, I had basically no problems with it and not many since, and this is the first time I have had an audio problem. About a week ago, all of my door speakers stopped working simultaneously. All of the audio and electrical equipment is OEM, and the radio head unit works fine, as I still get sound from all audio sources, either coming from the A pillars or, though i'm not sure if there are speakers there, from behind the dash. About 4 days after the speakers stopped working, I heard a sort of flutter from the passenger front door speaker that was sort of just a low rumble, and today i heard the same rumble/popping tgat went on and off.

I checked the wires connecting to the amp and saw no immediate issues (as far as my layman eyes could notice) in the wires themselves or the connection to the amp.

I basically have no idea what's wrong, and would like some insight and maybe a potential fix without taking it in to a shop. I just want to listen to something other than audio books again