Balanced audio connections are designed to reject some interference picked up along a cable run, which can be useful when connecting equipment over longer distances or in a setup with electrical noise. An unbalanced connection can work perfectly well for short runs and devices designed for it. The right choice depends on the outputs and inputs at both ends, not just on the cable’s appearance. Focusrite’s guide to balanced and unbalanced audio explains the practical difference.

What makes a connection balanced?

A balanced connection carries the audio signal over two conductors plus a ground or shield. The receiving equipment uses the relationship between those conductors to reduce interference picked up along the cable. Balanced inputs and outputs are commonly found on audio interfaces, mixers and studio monitors.

XLR and quarter-inch TRS connectors can carry balanced mono audio when the connected equipment is designed for it. TRS means tip, ring and sleeve; XLR connectors use three pins. The connector type alone does not guarantee a balanced connection, because the equipment and cable wiring both matter.

How is an unbalanced connection different?

An unbalanced cable carries the signal on one conductor and uses the shield as part of the return path. TS quarter-inch jack and RCA are common unbalanced connections. They are often used for instruments, consumer audio gear and short connections where the equipment expects that type of signal.

Unbalanced does not mean “bad quality.” A guitar connected to an instrument input with a short TS cable is a normal setup. The point is to use the connection the source and destination are designed for, and to keep an eye on cable length and nearby sources of electrical interference.

Match both ends of the cable

To get a balanced connection, the source needs a balanced output, the cable needs to be wired for balanced audio, and the destination needs a balanced input. If one device only has an unbalanced input, using an XLR or TRS plug at the other end does not make the whole route balanced.

For example, when connecting an audio interface to powered monitors, check the manuals for the interface’s outputs and the speakers’ inputs. If both support balanced connections, use the appropriate balanced cable. If you hear hum, test one change at a time and check power supplies, cable routing and other connected devices before assuming the cable alone is the cause.

Don’t confuse cable noise with phase cancellation

Balanced wiring helps reject certain types of electrical interference. Phase cancellation is a different issue: it can happen when two recordings of the same sound combine with a timing or polarity difference. Changing to a balanced cable will not fix a phase problem in two microphone tracks. See our guide to audio phase cancellation for that separate issue.

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