[5ynic]

yeah 30db is what I need. Thx.

 

[Maxvla]

DT48E will do it. 50dB isolation at 5KHz.

http://www.innerfidelity.com/images/BeyerdynamicDT48Eholescovered.pdf

 

[Dzhozef]

http://www.extremeheadphones.com/
 
these are apparently the "best" for isolation. good luck with your bats!

I have heard the EX-29, (their best model) and while I found the isolation to be excellent, the sound quality was sub-par, to say the least. (Compared to a pair of Sennheiser HD 280 Pros)