I received Vaughn's paperstone "Darthpants" in the mail this morning. I've been excited to hear Thunderpants ever since I listened to T50RPs - I liked their sound and technical ability, but something was holding them back. I was hoping that something could be removed via the Thunderpants damping and cups. Well... let's just say I wasn't disappointed. This has it all - high-end detail and extension, nice crunchy mids, and deep, hard-hitting bass. I have to say this is probably the best-sounding headphone I've ever owned. I tried some bass test tones just for fun, and these go down to about 20hz or so until it starts to fall off. It's pretty incredible how heavy the bass can hit when it wants to be. On Liquid Tension Experiment's Acid Rain, I could actually feel the kick bass - something I've never experienced before, "feeling" a bass kick through headphones. It was pretty sublime
That said, they are indeed extremely heavy - probably what makes them sound so good in the first place. Vaughn used rubber-cemented XB700 pads, which provide an airtight seal (and I mean airtight - my eardrums can tell). They DELIVER the bass like you've never seen. Unfortunately, the airtight seal comes at a price. The 2" thickness of the pads means that the heavy cups are further away from my head, which, if you know physics, is not a good thing. It makes the cups feel much heavier than they probably actually are, and any slight movement by me rocks the cups a little bit, which in turn changes the pressure inside the pads, which acts on my eardrums. It's actually a little bit annoying. I ran out to CVS when I got dinner to pick up a little container of rubber cement. I plan on trying Denon D2000 pads, which are quite comfortable and have at least a little bit of depth to them. I'm hoping I won't take away too much of the bass that the XB700 pads give while providing increased comfort.
That said, if you like the sound of the T50RPs, but want more - Thunderpants are what you're looking for (hey, that rhymed!). I'm looking forward to personalizing these headphones to make them the best they can be.
Also, a side note - I'll be receiving a pair of Darth Beyers (V2) in the mail in a week or two or three... it should be interesting to see how the original woody-cup-mod headphones stack up to the Darthpants. I haven't been this excited in a while!
EDIT: has anyone tried LCD-2 earpads with the Thunderpants? They seem like they would work.