Because how uncomfortable they were my ATH-M50s rotted in a case for the last year until I bought a Schiit Stack. I tried them on a whim and realized I really dig their sound. I hopped online and started looking for a fix.
* Note my ATH-M50s have am aftermarket removable cable mod
The first thing I decided to do was extend the depth of the ear pads using cotton. By placing a 1cm thick layer of stretched cotton balls under the pads I fixed a majority of the pain I experienced. The stock ATH-M50 pads are just too shallow for a guy with large ears. The more I used them, the more I fell in love with them. For about $1.50 in cotton balls I was able to use my ATH-M50s for extended periods of time.
Making the stock pads thicker and moving the driver off your ear greatly improves the comfort of the ATH-M50s. I recommend this mod to every owner. It's 100% reversible and cheap. You will be amazed at how much better your ears feel during extended listening sessions. I didn't notice a change in the sound signature either. Try it out and let me know what you think.
I decided to take the next step and look into replacement pads. There is a huge thread on head-fi.org about replacing the ATH-M50s pads. I read all 26 pages of the thread and many of the linked articles. There was no clear winner on which pads were the best. I ended up going with the Shure HPAEC840 Replacement Ear Cushions For SRH840 Headphones. They are larger and deeper than the ATH-M50s ear pads.
Shure 840 pad (left) vs stock pad (right), notice the difference in depth and overall size. Much bigger than the stock ATH-M50 pad.
The Shure pads fit a tad loose on the ATH-M50s, slightly more than the stock pads but not enough to fall off or freely rotate when using them. You can sew them to make them slightly smaller. I'm debating if I want to break out the thread.
The head-fi.org thread is full of people discussing about how the sound signature of the ATH-M50s change with new pads. I haven't noticed a change in sound but I have noticed a huge change in comfort. The Shure pads are plush and soft. I can wear the cans for hours on end and not feel any discomfort. Well worth the investment of time and money.
Shure 850 pads on the ATH-M50s