Just got mine from the most recent drop. I thought they weren't supposed to be numbered, but mine are in the 5800s. Highs were really harsh out of the box, but smoothed a bit after an hour or two. nice rich bass that extends fairly low. Got them in the cupboard plugged into an iPad and under a towel. They're way lighter and more comfortable than I imagined. My first pair of half decent open cans.

I saw this post by Tor4. Has anyone tried the felt rings with the K7XXs?
http://www.changstar.com/index.php/topic,2127.msg58309.html#msg58309

Thankfully, if your tastes are at all like mine, I've found using some of that 1/4" open-cell foam I've linked before in other threads works surprisingly well when placed in front of the driver. Cut it in a circle and just place it there. No need to take off the pads, as if it's cut to size, it'll hold in place due to friction. And the pads are large enough that the foam doesn't irritate the ears. This smooths out and attenuates the upper-mids and treble rather well. I actually quite enjoy them like this.

I guess hans030390's 1/4" disc of foam could be put under the pad and would be more comfortable on the ear. Mine already touch the inside of the cups, and I wouldn't say I have Jumbo ears.

All I have to do is hunt down an arts&crafts store in Taipei ... 

Try felt first.

Gotcha. Now I just have to find some.

The rings work, but add too much of it and you will end up with a very warm pair. About lowering the bass, I think you will have to dampen the driver further, perhaps you may want to try blocking the 'nipple part' of the cup vents with something porous like micropore or even electrical tape to see if it makes any difference.