I will test the HM5 pads for fit on the stock headphone when I get it Friday night.

I had some problems getting seal. They also seemed to fit me a bit too low even with the cups pulled all the way up.

The trick is to sit them over the upper-back part of the pinna where they don't exactly feel right or most secure, but after some warmup they will wrap, sound and seal better. The fit does get better with wear, but is not ideal by a long shot, specially considering the pad diameter (they sit a little too much over my cheekbone).

Thanks for the graphs!, did you try them with the lids off?. They are most easily removed if you unsecure the upper area first (by the hinges) and then pull it open like a door against the lower pin.

Didn't try to remove the lids. I think these might benefit from Jerg pad technology for both acoustics and seal.

So I went ahead and tried a partial jergpad mod (just the damping holes) and I must say that I regret it, tried from 30+ down to 4 holes (around 1mm in diameter) and no matter the configuration, the bass level was too diminished and the impact that I have become quite fond of was nowhere to be found. I then proceeded to duct-tape the very hurt pads back to normality. Maybe with other pads.

I did try the HM5 pads with the stock cups. The pads are a little larger, but when the pads are new and the rim is not stretched too much, you can use them. I used electrical tape to improve the seal and it worked nicely.

I've now had a chance to play around with these. Stock, they actually sound really damn good for $30. Even despite the price, they don't have very many major issues. Problem is, I couldn't get a seal with them unless I pushed them against my head. That doesn't do me much good.

HM5 pads definitely fit the stock enclosure. I think those pads give them a slightly darker sound. They are much more comfortable and make getting a proper seal easy.

I took to modding. My current configuration is on the warmer, laid-back side of things, but still not lacking much in detail and openness of the sound. Fairly clean sounding overall despite the warmth and additional bass. I don't mind the dip around 4-5KHz, as it makes it easier for me to listen without fatigue. It's much better than having a peak around that area for me. I can handle 7-10KHz peaks more easily. My configuration is as follows:

1. Layer of Dynamat in back of cups
2. Layer of Creatology foam on top of the Dynamat (in case you're wondering, it's purple)
3. 4 inch-ish long strips of Creatology foam and 2 half-inch-ish strips on the next area above the bottom of the cups, pushed into the corners (it's around half way up to the top of the cups)
4. Fairly thin disc of acoustic stuffing (feels sort of like polyfill) in bottom of cups
5. ~1/2 inch thick disk of what feels to be a medium density packing foam on top of that
6. Dynamat on back of driver magnet, covered with a layer of Creatology adhesive felt (non-stiff kind)
7. Ring of Creatology foam around driver on front side baffle, with a disc of foam or felt on top of that (glued at edges to the foam ring)
8. HM5 pads

I'm very impressed with this headphone and driver, and I'm enjoying what I'm hearing. It's headphones like this that make me wonder why I bother spending more on headphones sometimes. I also wanted to note that for whatever reason, it sounded better to me to put the acoustic stuffing under the foam disk than vice versa. I also had to use very little stuffing with the foam disk in there. I also don't remember exactly where I got the fabric/felt disk I placed in front of the driver. I think it came with a spare pair of ear pads I ordered a while back, but I've ordered too many different ear pads to know which pair it was. Or it came from a stock set of ear pads that I swapped something else for...