, you might want to start looking for TH-600 now, some say that it has been discontinued, its not listed on the Fostex site anymore under the "consumer headhphones"
I put up a mint pair for sale today in the classifieds...
Just got this rug pad in: http://www.amazon.com/gp/product/B006EK4I80?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
This is what HD800 modders use to tame the treble a bit. It does a great job, better than the Con-Tact that I also bought.
Just pull your ear pads off, cut them into a circle (~45mm), and put the circles in front of the driver grill.
It smooths things out just a touch where the treble is normally a little hot for me. Enough that I'm back to hoping someone grabs my DX1000 so I can hang onto these TH600s.