Quiet popping noise from speakers with key off

[SnowDrifter]

'05 tahoe w/ factory nav + bose

I noticed there's quite quiet intermittent popping noise from the speakers that continues for about 30 seconds after key off.

My google-fu hasn't turned up anything and I'm rather curious as to what this could be. The radio appears to shut off as normal, I don't have reason to believe there would be a short circuit to ground in any of the speakers as they all work normally.

 

[Mr. 960]

I would not worry about it if you can only faintly hear the popping. My 06 yukon with factory nav and bose does this every time I open the door for about 10 seconds or so.