Edit: Apparently I had a defective M50 that had very recessed mids. This mod does not apply anymore.
The M50's recessed mids always annoyed me because most of my cans have decent to smooth midranges. The M50's mid just didn't do it for me.
Here's a way to make it less recessed.
1. Take earpads off M50.
2. Peel back the pleather.
3. After peeling back the pleather, the layer of foam is exposed. Peel the foam off. Warning: If you peel it fast, the foam will rip (in case you want to reverse this mod). I've already peeled it off before, I'm only putting the foam back for demonstration.
4. Peel pleather back.
Here's a comparison picture, notice the vast difference in opacity.
To my ears, the mids improve, not radically, but noticeable. I've noticed it mainly from 600Hz - 3000 Hz. The highs also improve IMO. They also make the M50 more comfortable as the pads don't touch the ears as much. If you want to compare, peel off one pad and leave on the other.
Another mod is to take apart the M50 and remove the acoustic foam blocking the back of the drivers.
1. Take off earpads and screws.
2. Flip the cover, BE CAREFUL WITH THE WIRE. If you pull or let them swivel too much, they will break off from the solder. Loose the three screws on the back of the driver.
3. Flip the cover and you will see a white acoustic foam disk inside the plastic enclosure.
4. Take the foam out.
5. Here you can do one or another:
A. Cut the foam as shown in the picture, then take out the foam.
B. Use a soldering gun to take off the wires, and then take out the foam. Solder the wires back on.
6. Screw on the plastic enclosure and you're done.
According to my ears, this mod mainly improve the soundstage, timbre of instruments, and the mids . This mod might also increase the amount of bass(well, I did hear more bass, like 5% more). Another thing you can do is to take out the black foam in the middle of the driver. I haven't deeply analyze the change of sound by taking out that little foam piece.
With all these mods, it makes the M50 sound more fun IMO.
Edited by FearSC549 - 7/16/11 at 5:17am