When you played it later, are all the drivers producing a sound? If so, my guess is that the wiring inside just knocked against something else internally. Sometimes when I pick up my m22's and move them or carry them somewhere, I can sometimes hear a rattling sound.
You could also remove some of the front drivers and look inside to make sure all the wires are still hooked up. However, if they were not, one of the speakers would not be working.
Since we were steamcleaning carpets, we were walking around on towels we had spread in pathways on the floor. I did not have good access to speaker - I will verify tonight if all drivers are playing. I don't think anything got into the port and it didn't really sound like a loose wire. It sounded more like a nut or bolt had gotten loose and fell to the inside bottom of the cabinet and rolled around.
I take it that removing one of the drivers is no big deal? The bottom bass driver would be the obvious one to pull if I go that route.
