Created: Sep 28 2015 | Updated: Dec 07 2015
The USB on the back of your wireless audio device is for firmware updates only. The only exception is the original Crescendo, which can use the USB input as a dock for iOS device connected with an Apple cable.
The best way to stream music from a drive is to add a NAS (Network Access Storage) Drive to your network, or connect your USB drive to a device that allows connected drives to be accessed over the network. Most aftermarket routers include a USB port in the back allowing a drive to be connected.
The USB drive should be Windows formatted to either FAT32 or NTFS. Sharing may need to be enabled on your router.