Audio newb here. I have a pair of Presonus Eris E3s paired with a Eris Sub 8BT hooked up to my PC, problem is I don't know how to set them up so the volume control also increases and decreases the sub volume. The only way I currently have to adjust the volume is with the gain control on the back of the sub.
I don't currently have a soundcard, using audio with Realtek audio drivers. The E3s are connected to the sub and the sub connects to the PC via Bluetooth.