Balanced vs Unbalanced audio signal explained Learning Center

For people who are not clear of what this means

Mixers, audio interfaces and other audio devices may feature Balanced or Unbalanced audio inputs or outputs. So what is the difference?

In a nut shell a Balanced signal means better, stronger and cleaner signal between devices, It has nothing to do with left/right stereo balance. You can tell if your device has balanced outputs or inputs if it features XLR connectors or TRS connectors (tip-ring-sleeve) which are designed for a 3 conductor cable.

XLR balanced connectors are commonly found on outputs of professional mixers or line level balanced inputs on active studio monitors and recording devices. Even though they are the same cables used by microphones it doesn't necessarily mean that an XLR input connector is a mic input. Microphone inputs on a mixer or audio interface are part of a mic preamp.  

 When cost and space is an issue, manufacturers have offered an alternative 3 way conductor connection called TRS or tip-ring-sleeve connectors.

You can always connect two balanced devices with different connectors with a TRS to XLR cable or vice-versa.    

So why is Balanced signal better ? here's the geeky stuff:

-Interference reduction

A Balanced cable contains two identical wires, which are twisted together and then wrapped with a third conductor (foil or braid) that acts as a shield. The term "balanced" comes from of connecting each wire to identical impedances at source and load. This means that much of the electromagnetic interference will induce an equal noise voltage in each wire. Since the amplifier at the far end measures the difference in voltage between the two signal lines, noise that is identical on both wires is rejected. The noise received in the second, inverted line is applied against the first, upright signal, and cancels it out when the two signals are subtracted. This also prevents noise and ground issues in the signal and aloows to run much longer cables without problems.

-Louder

Compared to Unbalanced signal, Balanced signal adds about 6 to10 dB of   extra headroom to your equipment so your audio equipment will sound louder with less gain.

Conclusion:

Balanced connections are better and you should always ask if the gear you're planning to purchase offers this feature. Many Mixers or powered speakers have both, the importlant thing is to match devices connections correctly. If you can't make a Balanced to Balanced connection then it's better to stick with unbalanced to unbalanced.

Eric Warlaumont 11/17/2010