Hi, just bought a pair of these upon recommendation. Does anybody know whether they are loud when using with an mp3 player, and whether this is adequate? I ask because they appear to have a lower sensitivity that the free ones you are supplied with. I don't want a pair of headphones that are...

Hi, does anybody know the specification (sensitivity and impedance) of the free headphones you get with the creative zen vision:m? thanks

hi, this may be a question that all you experts have answered a million times, but as a newcomer in the world of sound, i was wondering: do higher impedance headphones use more power from my mp3 player? i have just bought a pair of koss portapros for my creative zen vision:m, and was wondering...