Speaker Setup

Hi guys, I've got a 5.1 Surround sound set (which I use as 2.1 usually) and a 5.1 headset. I have a problem...

The 5.1 headset takes the headset in the front, power in the back, and the input in the back. It has an option to switch between headset and speakers, a button for mute and power also. It can take individual speakers in the back. However, they are unfortunatley VERY quiet (totally unamplified) setup like this.

My 5.1 speakers don't have any inputs other than the speakers, but the connection to the main (front left) speaker is a like a VGA cable, so cannot be connected to the headset hub, instead goes through the powered sub which takes all the speakers into it.

I actually wanted two speakers running through the headset but amplified. But as there is no volume control on the headset hub this is not possible. I could plug 4 speakers. but not the left speaker or sub into the headset but this doesn't give me any more sound. Vice versa, the 5.1 headset will not plug into the sub at all!

Is there any way to reolve this without resorting to splitting ports?