Connections & formats

Balanced vs single-ended

Also called balanced connection, single-ended, unbalanced, differential

A balanced connection carries the signal on two matched conductors and responds only to the difference between them, so noise picked up equally by both cancels. A single-ended connection uses one signal wire and a shared ground; it is simpler and fine for short cables.

On a balanced line the hot and inverted cold conductors pick up the same noise, and the receiver takes the difference, so the noise cancels and the signal doubles. On a single-ended line the noise lands on the one signal wire and reaches the output.

For line-level connections between boxes, balanced XLR cables reject hum and interference that an RCA cable would pass on, which matters over long runs in a studio and rarely in a living room.

For headphones the word means something slightly different. A "balanced" headphone output, on a 4.4mm or four-pin XLR socket, drives each earpiece from two amplifier outputs with no shared ground, which can double the available voltage and removes one source of Crosstalk. The extra power is real and useful for demanding headphones; the improvement in sound beyond that is argued, and a good single-ended amplifier can measure just as well.

A single-ended headphone plug, 3.5mm or 6.35mm, cannot be converted to balanced with a passive adapter, because the cable itself has to carry separate returns for each side.

Related terms