Really? I always thought the standard high quality CD bitrate was 320. Everytime I've ripped one onto my computer it comes out 320I think actual purchased CDs are higher than 320. I know on my iPod adapter there is a gain adjustment to level it out with the other sources.
i had the same problem with my droid phone. but i found a aux setting on my hu and it let turn up the aux vol that the hu puts out and matched the vol with my usb output(close as i could) and its louder now. its not right on with the usb output but its really close.My music from my Ipod does not go as loud as the radio stations or the music cds that I play from my Kenwood Head unit. Could it be the aux cord that i'm using since its pretty thin? Volume offset is set to zero by the way.