This is what the dude was saying:
"The PX100-IIs were bassy and a little congested even when I received them second hand (although they looked brand new) which is why I mentioned the bass reducer thing, and turning up the volume very loud to get the best sound, etc... Well all that is no longer needed. I now listen with no EQ at all. The biggest improvement one can make to these cans sound is to stretch the top left and right parts of the headband outwards to make the fit looser. When they are tight, the bass is boomy and the vocals and mids are congested. The highs are also lost. Its basically just like when pushing anything hard into your ears, the sound gets muffled. try listening to some earbuds and hold them hard in your ears... Thats the sort of difference I am talking about here. Burn in also helped but to a much smaller degree than the headband stretching."
I did that, and it works very well. Not only do they sounds awesome, but they are much more comfortable not being pressed as hard against the ears. Highly recommended.
Edit: Oh yeah, very highly recommended... this is sounding incredibly good!
Another thing I might look into doing is getting the PX100 replacement pads for the PX100II, because this is what the dude had to say about them:
"Sennheiser PX100 Replacement pads
Ahh here we have a brighter sound vs all the other pads above except for the cryotech pads. Think of the cryotech pads with more mids and similar bass. My favorite overall pad for the px100-II. The most expensive but worth it! Think of this as the koss portapro pads with life added to the sound."
