i have a pioneer dehp-9300 deck wich has a aux hook up in front and back i just got a mp3 player to hook up to it and the sound just plainly *****. i have the mp3 player turned up all the way and the deck is up to 40. it sounds muffled its not crisp ect. i played the same song on a cd and i had to turn the sound way down to normal like around 20-25 why is that? it was a mp3 cdaswell. why would it sound different on a cd its the same format? is teh problem because its not an ipod? there are no aux specific audio settings on the deck and the mp3 player i tried messing with the E.Q. does really nothing. anybody help out. one more question if i get the pioneer with the usb hookup on the front face plate am i gonna run into the same problem?.........if it helps i am using a sandisk sansa mp3 player