this mod improves the beyer dt231 headphones' isolation. also, bass is tightened up. this is an advanced mod so do not attempt if you are a novice.
you'll need a small phillips screwdriver and some poster-tack:

the pads pry off:

take out the screws and save them:

apply poster tack around openings in the cup:

push the poster tack around the rim into the cup in an even layer. do NOT create an airtight seal when screwing the drivers back on:

you'll need a small phillips screwdriver and some poster-tack:

the pads pry off:

take out the screws and save them:

apply poster tack around openings in the cup:

push the poster tack around the rim into the cup in an even layer. do NOT create an airtight seal when screwing the drivers back on:










