The 2013 Sony Xb series includes the mdr Xb 400, Xb 600, Xb 610, xb 800, Xb 900, Xb 920, x05 and x10. So, if you were successful in reaching behind the drivers to remove the paper blocking the holes, post the steps here.
Update: I figured how to do it and discovered removing the paper behind the drivers gives a warmer sound with boosted natural mids between 300 to 1000 hertz and reduced the upper mids around 2khz to 3khz by 3 to 5 decibels. Most importantly, this mod boosts sub bass response from 20 hertz to 80 hertz.
To reach behind the drivers to removing the white paper coving the holes on the drivers:
1. Remove earcups
2. Remove black foam
3. Remove 4 screws
4. Snap earcups back onto headphones and pull slowly so the driver holder slips out, but without the earcups popping out.
5. Put super lubricant between the outer cracks if earcups pop out without the drivers holder sliding out.
6. Remove the paper behind the drivers
Warning: doing this mod will decrease noise isolation by about 5 decibels or 15%.
Edited by dementor338 - 11/19/13 at 10:14am