Elecraft KX3 - Speaker Issue

My KX3 had a rattling sound at low volume (whole KX3 case vibrated). The cause was the glue between the frame of the speaker and the speaker. The solution in my case: disassembling and cleaning the speaker.
I recommend to play video on a high volume (video postprocessing tool moderated rattling sound).
Music: Kopeika (et_) / CC BY-NC-SA 3.0