The Bose Companion 5 is a three-piece speaker system designed primarily for use with desktop computers and laptops. The simple cable connection to a computer's USB port lets you set up the Bose Companion in a few minutes. However, if you want to hook up the speaker system to a device that does not have a USB port, such as your home theatre receiver, you'll need an audio adaptor that converts the USB cable into an optical audio jack for connecting a fibre-optic digital cable. These are available online and at electronics stores.
Dial the volume knob on the top of the Bose control pod to zero before hooking up the speaker system to any device.
Connect the USB cable supplied with the Bose Companion 5 from the output on the rear of the Bose subwoofer, which is the largest of the three speaker components in this system, to the matching port on the "USB to optical" audio adaptor box.
Connect the optical cable from the port on the adaptor box to a digital optical audio jack on the rear of your surround sound receiver, or other compatible device with an optical jack.
Plug in the DC power cord supplied with the audio adaptor into the round socket on the adaptor. Plug in the other end to a wall outlet.