Apart from felt, you could also try paper. I used on some closed headphones and it works great!
Just get a tissue, peel of one layer, this layer should be really thin and see-through.
Then put the filter in front of the driver. Sound does not get muffled at all. It just smooths out the highs.
Good suggestion, I tried it and didn't notice any significant change in the sound, except for the bass sounding boomier. I decided not to keep the modification, thank you for the tip though!
So how thick should the felt be?
And should the circle of felt cover the entire driver? So should the circle have the same diameter of the inner pads?
Or is it a ring shape, with a big hole in the center to let sound come through? If you're literally covering the entire driver, with let's say 3-4mm thick felt. The sound is going to be way muffled.
Curious as well.
Yes, there are two other things that you can do. The first is to do a little gentle shaping of the metal headband. Just grab the headband, not the cups, at the ends before the cups and give a good but gentle stretching of the headband. It's metal and it will reshape making a looser clamp.
Secondly, be sure that you rotate the cups on the x, y axis to get the best custom fit. Some people do not understand that you can do this.
Thank you! That actually helped quite a bit. And yes, I had made sure to rotate the cups. I had read an earlier post about that and made sure to try to get the best fit that way first.
Also wanted to give you some thoughts on the ear-pads, I feel that the velour ear pads from the DT990 were much nicer. I'm starting to realize how spoiled I was with that headphone!