[Sam21]

I am doing some searching on this Fostex T50RP.
 
Apparently, there are two versions of this headphone:
 
1) normal one
2) the one with Improved Transient Response
 
I know that for the former i need to do some mods. How about the latter ? do i still have to mod it ?
 
 
And if i have to mod both, what is the easiest and the most effective mod ?

 

[GREQ]

Unfortunately for you, you've just opened up a huge can of worms (for yourself).
Fortunately it's a magical adventure!
 
Here is the biggest tomb of knowledge that exists on the topic anywhere:
http://www.head-fi.org/t/618659/fostex-t50rp-incremental-mods-and-measurements
 
I actually own a Fostex T20RP MKII modded by the author of this article, and I can testify to these mods - they sound absolutely brilliant. I can only imagine how good a T50RP must sound with these mods.
 
I've never heard of two versions of the T50RP... maybe you've read about the original and the MKII which is the current production model. I wouldn't worry too much about that, and just get the MKII and enjoy the modding. 
Whichever you get you'll most probably want to mod it.