I've read that you use the Beyerdynamic DT770 headphones a lot.
I'm also a great fan of these headphones and I'd really like to know which impedance version do you use, if you've ever tried the other versions and what do you use to drive them.
Have you ever noticed any decrease in high frequencies through the years?
Because my old ones don't sound as bright as the newer ones.
Correct, the high frequencies do die down after a while on the DT770s. I use the freshest pair in my studio for critical listening almost daily, and recycle the older sets to the musicians for tracking. The drummers will get the oldest pair, because their high frequency hearing is usually shot anyway. Hahaha!
The DT770s are loud enough to make rock bands happy. And they stay on everyone's head pretty well as everyone is thrashing around. They last a long time and are easy to buy replacement parts for. I've swapped out many drivers, ear pads, head bands and cables. The grey fuzzy ear muff get nasty after a while, so it is pretty easy to tell which headphones in the collection are the new ones. They have the fresh fuzzies!!!
I usually use the "Pro" 250ohm models, because I can drive them pretty hard with my headphone amps. During tracking we have a Furman HDS-16 headphone system with 6 individual boxes for the players. Probably one of the most valuable pieces of gear in my studio. Why? Because musicians are not as cranky when they can fiddle around with the knobs and make their own mix.... and when musicians are happy, we get more work done and it's a helluva lot more fun!