I just get a couple of these for my two daughter . they have the same sound as the mx-500 . consider that the cord be only 3 ft. long , and just about anything you hook it up to be likely to have a volume control , a volume control on the cord be pretty redundant . in fact , the other day , I have the mx-500 plug in for a long time , and then forget that there be a volume switch in the cord . as the day wear on , I could not quite figure why the sound volume be drop . it be only later that I realize that the volume switch have accidentally get bump down . so save a buck or two and get the mx-400 instead of the mx-500 . I have already review the mx-500 earbud - I 'll just repeat a few point about the mx-400 , since these be the same earbud : if you be a Sennheiser fan , these earbud have that classic sennheiser sound - a rich , ring clarity in the mid and high , and no excessive bass boost . like all non-sealing earbud , the bass be variable and get louder the more tightly the earbud be couple against the earhole . how tightly you get they to fit depend on you ear anatomy really . as for get they to stay in place , I discover that the best way be to wear they upside down and loop the wire around the back of my ear and under my chin . a alternative way to wear these earplug , much more discrete , but also a bit less secure , be to loop the wire over the ear and around the back of you neck , like sunglass strap . a small paper clip to the back of you collar will hold the wire in place and you can run the cord around inside you shirt .