@happyram I'd use a Dremel too but I am not sure if this will really work. Sure, you could try and remove as much of front and back enclosure as possible, but I do not think that will improve your sound. The enclosure was designed for the speaker and the sound worked without issues first. Even years of usage would not change that. Take a closer look at the speaker and the speaker membrane. I could imagine that the issue is related to bad speaker(s)
[guide|61194]
[guide|61194]