Anyone else decide to do the HD650 mod that purr1n posted in this thread besides me , purr1n , and hans, and if so, what do you think? I agree with purr1n. To me they seem less damped and more "alive" - and on my particular setup, even the sound stage sounds a little better. The great part about this mod too is that it is easy and cheap to reverse the mod (the foam behind the driver under the grills may be tricky) but you can easily and cheapy replace the foam on the inside of the cups over the driver. Great mod for my tastes.
I completed the mod today after getting my replacement pads which came with the foam inserts. Used the quarter and blade method recommended by purrin. Now, I got the HD650 late last week, so I never
merged with the stock sound. Which probably makes my impressions more or less useless. However, I can say something like this: I have the sense of an improvement with respect to attack - like it hits harder and quicker. This could contribute to an increase in perceived liveliness. But I'm still learning my words.