I wonder if it's somehow possible in mac to divide 2 channels to 6?

I can't do it in Audio midi setup, because all channels except main is disabled. I can't change volume that is. mac knows I have 6 speakers and I can send test sound to it (white noise) from Audio midi setup. I also can send audio to any of the speakers but 2 at the same time. For example left channel to sub and right channel to front right.

In linux I can write script to divide channels to 6.

What can I do in mac if I don't have the drivers?

ps. I have sound blaster external usb 24bit soundcard