What Is a Ground Loop and How Do You Fix It? – Arendal Sound

If you are hearing a low-frequency hum or buzz through your speakers, especially from your subwoofer, you might be dealing with a ground loop. It is one of the most common and frustrating noise issues in audio systems.

What Is a Ground Loop?

A ground loop occurs when two or more components in your system are connected to different grounding points, creating a small voltage difference between them. This causes unwanted current to flow through your audio cables, which introduces a hum or buzz, typically at 50 hertz or 60 hertz, depending on your region.

How to Know It Is a Ground Loop

Common signs include:
    •    A steady hum or buzz, even with the volume turned all the way down
    •    Noise that changes depending on whether a device such as a TV or computer is connected
    •    Noise that disappears when certain cables are disconnected, such as the RCA going to the subwoofer

Possible Fixes

1. Use the Same Power Outlet

Plug your AVR, amplifier, subwoofer, and source components into the same power strip or wall outlet. This often removes voltage differences between grounds.

2. Add a Ground Loop Isolator

Install a ground loop isolator (RCA or XLR type) between your source and amplifier or subwoofer. These are simple devices that are widely available.

3. Switch to Balanced Connections (XLR)

Balanced audio cables help reject noise and minimize grounding problems. If your equipment supports XLR connections, this is often the most reliable solution.

4. Test HDMI Sources

Some TVs or cable boxes can cause ground noise through HDMI. Unplug the HDMI cable and see if the hum disappears. If that helps, an HDMI ground isolator may solve the issue.

Final Tip

A ground loop is an electrical issue, not a speaker defect. Filters and isolators can help, but the best long-term fix is clean, consistent grounding and proper cable management.

If you are unsure, unplug devices one at a time to isolate the cause. This simple step often reveals exactly where the problem starts. In more extreme cases, particularly in homes with outdated electrical systems, it may be necessary to consult an electrician to install a dedicated circuit for sensitive audio equipment.