Audio
Balanced vs Unbalanced
01 — Definition
The trick that lets a signal travel 100 m without picking up noise. A balanced connection carries the signal plus an inverted copy on three conductors (XLR or TRS); at the destination the copy is flipped back and summed, and the noise picked up along the way cancels. CMRR puts a figure on the quality of that rejection — expect >60 dB CMRR on pro equipment. Unbalanced (TS, RCA) has only two conductors and no rejection: around 3 m of usable run in an RF-noisy environment.
02 — In the field
A 100 m balanced run in a noisy venue is routine; a 6 m unbalanced run alongside a dimmer rack will hum. When you cannot go balanced, keep the runs as short as you can.