How to Fix Static or Humming on Home Theater System

Authored by: Support.com Tech Pro Team

1. Introduction

In the case of static or humming while listening to your home theater or surround sound system, this could be caused by a loose speaker connection, or even the content itself. These steps will take you through some things to try to resolve static or humming.

2. What Can Cause the Static and Hum

There could be several reasons why your system is humming at you or producing static filled feedback. Ground Loops are one common cause, while frayed wires, and interference are others.

What is a Ground Loop

A ground loop in home theater equipment occurs when one or more pieces of equipment are plugged into your power at different locations, then connected together by electrical signal cables (RCA, HDMI, composite, component) whose shielding is connected to ground.

When a ground loop problem exists, you'll hear a low frequency hum when you plug any audio or video components in an electrical outlet, because it creates a single-loop antenna that just loves to use electromagnetic induction to suck in various types of noise and make annoying sounds.

Anything that breaks the loop will remove the noise. The easiest way to do this is to plug all of your equipment into a single power strip and then plug that strip into the wall.

How Can Wires Cause Issues

While modern cables and wires are well shielded, running power cables next to audio will cause unpleasant interference.

A poorly made or old cable can also cause issues.

RF-Interference

Cell phones, WiFi equipment, and computers all can cause radio frequency interference with your Home Theater System.

3. How to Eliminate or Minimize the Static and Hum

The humming or hissing you're hearing could be coming from any one of the home entertainment components you have hooked up. The best way to determine which device is causing the sound is to methodically disconnect them one by one.

Before moving your equipment or checking any cabling, make absolutely sure that your A/V Receiver and any other components that are currently on are fully powered off.

Check Each Device Individually

To start with you need to know what device or cable is causing the noise.

Just remember, you need to take your system down to its simplest level. Find a way to hook the system up with as many pieces of the system disconnected. Remove the source of the humming first by removing as many pieces of your kit as you can. Then start adding back components one at a time until the hum returns.

If the hum, static, or hissing still persists after checking those devices, you'll need to disconnect each component individually and test them. Unplug each speaker and test them separately. One of them may have the sound problem and need to be replaced.

Check for Frayed or Damaged Cables

As you go through and check each device, it's important to look over the wires and cables. Make sure none of them are frayed or damaged. Damaged wires not only may cause sound problems but can also be a fire hazard.

Use One Outlet or a Ground Line Voltage Filter

Try plugging all your devices into the same outlet or power strip. Doing this prevents a ground loop. If after plugging into the same outlet, you have no hum, you definitely had a ground loop. If plugging all of your equipment into one outlet or power supply is not feasible you may need to consider a ground line voltage filter.

Check Your Cable Box or Use an Isolation Transformer

If your system includes a cable box, disconnect the cable line and see if the sound disruption stops. If it does, you may need a new cable box or an isolation transformer to prevent interference with the coaxial cable.