Hey I'm real new to quality headphones (quality for me being anything above 50$ lol) and i just purchased some Sennheiser HD 448s.  They sound great, but I wish I could change the material on the ear pads to something a bit more cushy and comfortable. I have seen on other topics that people change this, but I can't find a site or anything that sells different pads for headphones.  Am I not looking hard enough? Or do you have to take the pads from different headphones?...