Tak's stupid HD700 mods: part 1
--Disassembly--
Before I get into the mods I've done so far and the resulting sound, I'm going to go over how to disassemble this headphone. It's relatively simple, but I don't see any tutorials on the internet, so this should prove useful. For the sake of progress, I'll only post how to take apart the earcups for now. If I figure out the headband after I'm done making it not sound like shit, I'll add a guide for that as well.
--Stupid disclaimer bullshit-- This is an expensive headphone. Judging by it's construction it's clearly not intended to be serviced by the end user. I'm not to be held responsible if you break it while following this guide. If you acknowledge the risks involved, and are okay with that, keep reading.

For the cups, the only tools you need are a used gift card, and an unused zip tie. There are three pieces to it in total, not counting the driver, all of which are held together with small clips.

Release the first clip on the front of the cup, right below the aluminum yoke, with either the card or your fingernail. This requires almost no force, so be gentle. This outer piece is thin and probably very fragile. I'm going to assume that if you're trying to mod this headphone, you've already given the instruction manual a good once-over, and are familiar with how to take the pads off. So, go ahead and do that too.

After that, take the gift card and slide it under the edge you just dislodged. Again, be gentle. Slide it up and through either corner of the earcup, then through the "arm" that connects to the driver. The clips you are trying to release are in the center, four of them surrounding the driver. Once you have it thoroughly jammed under the piece, pry it up slowly. It should come right off, though it can be somewhat stiff/difficult on the first attempt.


This inner piece clamps the driver and cable detachments into the cup. First, you have to release the clips at the base of the cable inlet. Just release the clips,
do NOT attempt to force it up yet. 
After that, keep the zip tie at hand and look closely at the driver. There are four small gaps between the driver and the clamp piece. Pick one and...

...slide the zip tie through like so. You may have to inch it in and grab the end with tweezers or needle-nose pliers to get it all the way through. Afterwards, fold it in half and grasp both the cup and the ziptie firmly. Pull. This will release all four inner clips at once. As such, it requires a lot of force, but don't worry, you won't break it.

If you want to take the driver out, first release the clips on this PCB, right here.

The driver is further held in by four clips on the outside of it. These can be released one at a time with just your fingers. Sennheiser doesn't have spare drivers on their headphone spares site, so be careful.

Alright, that covers the disassembly. Next post: enclosure and damping mods... running out of space on my dropbox, that's why this damn post took so long. Sorry.