The online audio nerd community can be enthusiastic, but they're going bananas for these DIY headphones. Thunderpants are made in Seattle by forum regular Smeggy, who turns a $US75 pair of cans into some of the finest in the world.
Smeggy's Thunderpants are modified versions of Fostex T50RPs -- a popular model audiophile hackers like to go after. Smeggy (né: Gary) leaves the excellent stock drivers alone and fits them with custom cups made of beautiful woods. According to Jude over at Head-Fi, Smeggy's closed-back Thunderpants "measure with some of the finest in the world."