I have just modded my SR60's as a result of this inspiring thread. I removed the grille clothe, dampened the magnet and back side of the button, and punched all 10 holes in the clothe around the driver with a pen. Note to others who haven't done this yet, maybe don't punch all 10 holes right away. Total modification time, around 2 hours. Most of this was spend reheating my tea pot, adding water to the pan, and worrying about whether I was wrecking any electronics.
On to my emotional first time reaction when trying out the modded cans...SERIOUSLY!!!! What in the world happened here! Completely different headphones. That is a lot of bass!! I'm thinking I should have poked only 4 or 5 holes. I may go back in and cover up a few. This is a huge increase in bass, especially in the mid-bass region which can prove to be too much on certain tracks. Wow, do these things have a lot of kick now.
The added warmth is nice. As well, there is slightly more detail in the mids and highs, which is great. And this was completely free.
The really interesting thing here is that the soundstage feels increased big-time. In fact, I never really noticed much of a soundstage with these cans before. Now, these really capture me with a lot more depth and width. There is also a new airyness to the sound. Kind of an open, breathy, delicate type of thing. But they still retain most of the Grado attack and punch. These now sound like a really pricey pair of cans.
My initial listening setup for the night was an Apple Airport Express>Little Dot MKIII with 6J1P-EV driver tubes>modded SR60's. The 6J1P-EV tubes add some increased bass, and with my newly modded SR60's, this is actually too much bass for my liking. I think I'll pop my Mullard drivers back in and see if I can find perfection. Next I plugged the SR60's straight into my headphone out of my Ipod Touch 3rd Gen. This is REALLY nice. I can't believe how great this sounds. Playing with EQ FLAT, everything pretty much sounds exactly like it should. Bass is almost too much, but not quite. I can't believe unamped sounds this good, perhaps better than going through the tube amp. The only thing the tube amp improves on is added sub-bass, but that could be just the specific tubes that I'm using.
I'm trying to think of how this modification may have negatively affected the new sound signature. The really fast mid-range may have slightly less attack than normal. Not sure though. This may be just because the bass is increased now, giving the impression of slightly lesser mid-range attack. Who knows...anyway, this makes me want to know what I can all do to my DT880's in the bass region.
Excellent money-saving thread here.