posted on Fri Jun 19, 2009 7:09 am
That won't be doable (without extra hardware) in your current situation, I think. The reason being that since it's optical, it's a digital connection. The Xbox 360 gives you 5.1 Dolby (IIRC) through that cable. In order to get 4.1 from that, you'd have to downmix the center channel into the L/R, which would require some form of software processing. And you can't just go and install some utility on the Xbox 360 like that. I don't own a console, but you might want to really dig into the sound output settings on the Xbox and see if you can set it to 4 or 4.1 speakers there.
If you have a small mixing desk, you might be able to do it via analog, by passing the signal through it first. So L = 50 % L + 50 % C, and R = 50% R + 50%C, or something like that. But even this would be a bit of a long shot.
There is a fixed amount of intelligence on the planet, and the population keeps growing :(