Balanced Audio vs. Unbalanced Audio in Simple Terms

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To understand differences in audio between balanced and unbalanced signals, you first need to understand what makes up a signal. Inside an audio signal you have an electrical current that carries the signal at a rate based on signal impedance (resistance to current) and conductivity (how sensitive a material is to electricity). This means that some cables and connectors are better than others. There's a reason why some manufacturers use oxygen free conductors.

In an audio cable we have a wire that carries the electrical signal. This wire "carries the audio." In an unbalanced cable we have two "poles" or "legs" that carry the signal. Along the way this signal will pick up noise on either the positive or negative pole or leg. This is common noise from electrical components that is blended into the signal. Unbalanced cables do not filter this noise out. They introduce too much noise into the signal causing the noise floor to be excessive.*

Here's an example: You have a PA system with system noise running at -20dB. Everything in your system has to be over -20dB to be an adequate signal that exceeds the noise. This means that the goal is to get as far as possible from the noise floor. "Great" equipment has a large dynamic range meaning in simple terms that is has enough signal strength to move adequately away from the noise floor.

*The noise floor is the level of the noise in a signal.

With balanced cables, the positive and negative legs (poles) cancel out any noise that gets introduced into the signal. You therefore have a cleaner signal.

Note: Unbalanced cables work well at short distances and you will often seen them used as patch cables.