I HAD the same problem, but i found a solution that worked… at least for me… i found out that my left tweeter was blown and when the volume hits 80% or higher the sound just dissapeared until the volume was under 80% back again.
So you can do 2 things. Cheap solution or best solution. I chose the Cheap Solution.
Solution 1:
find out which tweeter is blown up, you cab recognize if its “pushed”
(you can see the difference…)
And simply disconnect 1 of the 2 wires and don’t connect them together (just tape them together)
Screw the tweeter back in, and you should be fine, but to be honest sound quality is a tiny bit poorer but this is the easy and fastest way :)
Solution 2: Just replace de bad tweeter.
Hope that helps :)