'Balanced' vs 'Unbalanced' Audio Connections

[snyprrr]

I'm too embarrassed to Post this at the electronics site!

I have totally confused myself, even though I do believe I know the difference. Can you, in some analogous way, explain the difference, maybe with an example or two?


If I were pressed right now, my answer would be that 'unbalanced' doesn't take into account 'Stereo', whereas 'balanced' has the stereo thing worked out. Yes, I'd probably have been shot for that answer. (I think normal 1/4" phone jack-guitar cables are 'unbalanced'- they don't have the "ring tip sleeve" thing,... oy, am I feeling stupid here!!)

HEEELP!!

[snyprrr]

this is much more important than the other topic. please help!!!

[71 dB]

Unbalanced: Signal is presented as "hot" and "ground".
Balanced: Signal is presented as positive "hot" and negative "hot"

Signal value is the difference. So, in unbalanced system we have "hot" - "ground" = "hot", because "ground" = 0. In balanced system signal value = "hot" - negative "hot" = 2*"hot".

Noise inducted to the wires is eliminated in balanced system because noise - noise is zero. Balanced systems are handy in studious were signal to noise ratio must be very good and the wires usually quite long. In home environment unbalanced systems are usually good enough.

[SHOOTOUT!]

Good explanation here:
http://whirlwindusa.com/support/tech-articles/unbalanced-vs-balanced-lines/

Balanced cables have the interference cancelling out between the two signal wires, and the shield if there is one can be lifted to prevent ground loops unless providing phantom power.

Also don't get confused by thinking that balanced must be on XLR lock in connectors... these are just a superior way of connecting (other than being more likely to pull things over than 1/4 inch jack plugs).

Cheers,

Marc.