Originally Posted by Kukuk
I can't say it's ever changed sound in a meaningful way for me.
Sometimes a little work beats tossing cash at a problem to solve it. It's absolutely absurd to recommend buying new pads every year when washing works just fine.
I guess this is one of the reasons when I buy used headphones, most of the times the pads are in such dismal state....
Pads' integrity varies depending on the materials it is used. Grado flat ones and expensive p/leather with good damping materials may last several years (like many of Japanese ones), but cheap vinyl pads and those German velour pads with weaker damping material, in general, are not designed in that way.
It also varies that the condition the pads are being used. OP may used the headphones all the time, or maybe he is not. Also the chemicals naturally applied (i.e skin oil) are the factors. Force applied by headband also varies depending on individual's head size. The fact is, however, velour used for those pads is not known for its durability.
My experience with all of these Sennheiser pads and Beyer pads on headphones I frequently use; even with routine washing, velour pads are eventually worn out; not just only surface, but the damping materials themselves also collapse inside, making the pads 'thinner'. Same goes for my friends' ones. I haven't seen any velour pads last longer than 2 years for regularly used headphones. Most of time, if they use headphones regularly, those pads are crushed inside and become nearly-non-functional at a year or a year and half.
I can't tell detail because OP's picture camera angle is rather bad to decide things, but my guess is damping materials are pretty damaged and surface color is changed a lot. It does not just mean the pads are dirty; there has been chemical processes already being done on the pads; washing will make those pads 'white' it won't be even close to the original state. OP may get satisfying result only if damping materials are somewhat still strong enough, otherwise replacing pads is usually recommended to do so.
And no, it is not absurd at all. 23.5 EURO for entire year is nothing. If you can't save 0.06 Euro per day for pads, and If you are in such poverty, it's better to sell off the headphones and use the money for better purpose.
Edited by wnmnkh - 9/7/12 at 6:25am