Headphones from a 5.1 surround sound system

So i'm thinking of getting some gaming headphones so when I game on my 360 I don't annoy my flat mates.

I want to get the turtle beach HPX which says it requires the astro mixamp for 5.1

I currently run my xbox optically via my logitech z5400 5.1 setup.

If I use this with the headphones will it produce 5.1 surround sound without the need of the mixamp?

When I use really bad headphones it apppears to produce 5.1 but they are so bad I can't really tell.

Thanks

The HPX does not need the mixamp to make it 5.1, it needs the mixamp to connect while using XBox360. Thats one of the best setups you can buy, I would go for it or just buy the TB X41.