Speaker covers?

the thing is, theyre not very tightly in place and so whenever i put the volume up i can hear the plastic buzzing with the bass, so i took them off.
do they serve any useful purpose such as keeping dust and dirt away from the speaker, or does that not matter? im thinking of making a custom piece to cover everything up but expose the speaker so is that a good idea?
whats a PITA?
im thinking of designing a cover that shows the speaker while covering the other parts

