Has someone tried doing the quarter mod first before taking the foam out of the back to see how much of a difference the rear foam removal makes.

I have not tried the quarter method yet, was thinking about it though. I am just a little nervous because I have never modded a headphone before, I am scared I may accidentally puncture the driver or something, unless there is an easy way to take the foam covering the driver off by removing the earpads. If I were to try the quarter method, I like hans idea of drawing a circle around the driver (with the foam still on) then figuring out a way to remove the earpads and take the foam covering the drivers off - then cut the hole in the foam that I drew using hans method, then replacing the foam and earpads. I do want to try the complete mod that purr1n posted, I am just too worried that I would screw something up. I have no idea how to remove the grills without bending them, and even if I did remove them, I would be afraid I wouldn't be able to get them back on. But if you just want to try the quarter method, and you know how to remove the foam covering the drivers, you could use hans method of drawing a circle around the driver before you remove the foam, or you can remove the foam and use the quarter method purr1n described then simply replace the foam.

Thank you for that tip JoelT! I really appreciate it! Any tips on removing the grills?

Thank you once again JoelT! I sincerely appreciate the help! 

Here's how it measures on our rig.

That would be awesome hans, thanks to JoelT I was able to get the earpads off and access the foam, but I am still a little nervous about popping the outside grills off. Also, as far as making a whole in the foam to expose the driver, I was going to try either the quarter method, or the method yuo described hans as far as drawing a circle around the driver. My question is, what tool should I use to cut a perfect circle in the foam like the one in the photos? an X-Acto knife? Or is there an easier way?

And thank you hans for offering to post step by step instructions, it would help me out greatly since I have never modded a headphone before and since these are the best headphones I own, just a little nervous - so step by step instructions and pics would help out greatly -thank you hans and thank you JoelT.

EDIT:

 Sorry Ultrabike, I somehow missed your post with the video, just saw it - Thank you for the post!!!