I think the treble is really, really good even on the stock T50RP - somewhat recessed perhaps, but of very high quality. You will see it if you look at CSD graph for this headphone. Not sure I can find one at this time, but I may post it later. The treble on T50RP is extremely fast, while the bass and mids are far slower and more resonant on a stock pair.
My God, I can't believe how huge this thread has gotten! Back when I started it, these headphones were hardly known on this forum. Fast forward 3 years and we have Thunderpants, Paradox, Mad Dog's and a bazillion other modifications of these and nowadays it seems like every head-fi'er and their mother wants to own one and mod the crap out of them. lol I went to the local audio store where I auditioned my first pair before starting this thread. Turns out that the T50RPs are regularly in stock there now and that every salesperson at the store seems to know about them and how they are popular headphones for modding on head-fi. I then visited another audio shop in the area and there they told me that they should also start carrying T50RPs soon due to high demand. lol
Edited by Pianist - 11/9/12 at 3:11pm