Just a quick question - and I think I've found a band-aid solution - but just want to throw this out there in case there's more that I need to worry about. It's a 2020 model, and therefore still under the 5-year transferrable warranty. I have a GK Neo IV 1x15, and I set the head directly on top of the cab. At higher volumes (EQ set flat), there is an internal buzz / rattle. I can tap on the top / bottom of the head and hear the same metal-on-metal rattle, and have tightened all of the external screws. Solution: I've set it on top of a cushion and bungeed it to the cab (and also put the head on the floor next to the cab). Problem solved. Simply something loose internally, or probably a commonality amongst lightweight heads and powerful cabs? Just curious.