Simple Explanation

An unwanted buzzing or humming noise caused when electrical equipment has more than one path to ground.

Concise Technical Definition

A condition in which multiple ground paths with differing impedances create voltage differences, resulting in audible hum or interference in audio systems.

Layman-Friendly Analogy

Like a tug-of-war between two drains—electricity gets confused about which way to go, and you hear the result as noise.

Industry Usage Summary

Common in complex audio and AV setups, especially when multiple devices are powered from different outlets or grounds. Solutions include ground lift switches, isolation transformers, and careful grounding practices.

Engineering Shortcut

Multiple unequal ground paths = voltage offset = 50 Hz/60 Hz hum.

Full Technical Explanation

A ground loop occurs when two or more devices in an electrical system are connected to ground at different points, and a voltage difference exists between those grounds due to variations in impedance. This difference creates a loop current that can induce a low-frequency hum (typically 50 Hz or 60 Hz, depending on the AC mains frequency) in audio systems. Ground loops are especially problematic in interconnected AV equipment where signal grounds and power grounds mix. Preventing ground loops involves minimizing redundant ground paths, using ground lift switches, or isolating devices with transformers or DI boxes. Proper system grounding design is essential for maintaining clean signal integrity.