Are You Unbalanced? - Balanced vs. Unbalanced Audio
Balanced vs. Unbalanced Audio
iConnectivity's founder and CTO came up with a couple of very good video links about why balanced audio is a good thing.
What is balanced audio?
It's a 3-conductor wiring scheme for connecting equipment, designed to eliminate noise pickup along the cable run. Normally, balanced connections are preferable to unbalanced.
How does it work?
In addition to the positive and negative connectors, there's a third one - the shield (aka ground). The idea is that the same noise is picked up by both the negative wire and the shield, the shield is reversed at the receiving end, and noise picked up along the run is canceled.
It's called common mode rejection.
This is courtesy of KIQ Productions, publisher of "Total Recording," by Dave Moulton. The noise you pick up along the run won't look like the sine wave here, but this illustrates the point: if you reverse one wire and add the two together, you get silence.
And if you're just a little more nerdy:
Should I suffer low self-esteem if my equipment is unbalanced?
Probably not! If your system is already hum-free, there's no reason to change it. The longer the cable run, the more you're at risk of picking up noise.
Furthermore, occasionally you can actually create ground loops - hum - using balanced cables with equipment that isn't designed to avoid it.
But once again, balanced is almost always better than unbalanced.
Should I buy balanced 1/4" TRS cables or unbalanced 1/4" cables for my unbalanced equipment?
You can use TRS (tip ring sleeve) cables in any unbalanced input, because the ring and sleeve are connected by the jack. That future-proofs your cables - says the guy writing this blog, who made that mistake once a long time ago. Also, see the following.
I've heard it's a good idea to use 3-conductor cable but cut the shield or something when using unbalanced equipment. What's that all about?!
The conventional wisdom is to cut the shield at the end of the run, leaving two conductors. It's not as good as a "true" balanced run, but you're using the shield as extra protection from noise pickup on the cable run.