[Gislason]

Been having some problems with wax build-up in my Denon C751 IEM's causing a lower output and a muffled sound. Today at work I was fed up and accidentally pierced a little hole through the "protecting surface" while attempting to clean them with a sharp edge when frustrated and stressed.
 
I assume this might cause build-up inside and ruin them totally but hot damn, the sound really opened up, unbelievable clarity and the sound moved much closer making electronical music almost buzz in my head and instrumental music have much more room, still retaining a good and tight bass.
 
It might just be a relative impression but I wasn't this impressed when I bought them. This sound is real good.
 
I don't know what you call this surface but it must be to protect the membrane from wax. It really seems to make an impact on the sound, wax or not. Anyone come to the same conclusion?
 
Might have been discussed before, I'm new here. Just thought I would share my accidental eargasm 

 

[Gislason]

Been listening some more and realize that the treble is a bit strong and the sound lack a bit of the mids, the sound feels much more "honest" though. Wonder what I'll buy when these go junk, I'll probably look to upgrade.

 

[mvw2]

Helps to run a longer tip on these instead of the stock single flange tip.  This tends to even out the bass and treble.
 
The thing you pierced is simply a wax guard.  It does very little in terms of changing the sound...unless it's getting plugged up.  These are replaceable filter "stickers" pretty much and used on a lot of earphones. 

 

[Gislason]

Thanks for the info and tip mvw2, I appreciate it!