The charging base is also a wireless transmitter which sends the audio to your headphones wirelessly.
You send 6 channels of digital sound out of your computers digital (optical) sound port, and into the digital IN port at the back of the charging stand, using the digital optical cable that comes with the headphones.
You then send 3 channels of digital sound between the charging stand and your PC using the usb cable -which also comes with the headphones.
So for this to wrok you need both the digital audio cable and the usb cable connected at the same time.
Read page 20 in the manual.
https://support.turtlebeach.com/hc/a...User_Guide.pdf
The pre-requisite is that you would need a free usb port AND most importantly an optical digital out port on your soundcard.
So before you spend any money, the most important question is:
What is your current sound card? and does it have a digital out port? (there should be a red beam of light coming out of it when it is on if nothing is plugged in)