How do you do this, without shorting the 2 front inputs together which would obviously make a mono signal? Do you use isolation transformers to split the centre signal? I'm talking about line level here btw
By 3d, I mean companies keep adding all these channels around the listener in the left/right/front/back directions, but not in the up and down directions. eg. If a plane flies over from behind you, the sound doesn't, it just goes straight through you from front to back. How long will it be...