How to Fix Static and Hum on Surround Sound System

Authored by: Support.com Tech Pro Team

1. Introduction

You've got your surround sound system fully hooked up but when you turn it on you hear an annoying audio anomaly. The audio disruption usually happens in one of two ways: A high pitched buzzing, rasping static like an angry insect or a low droning hum. Keep in mind, some of your media may have this sound in it. For example, if you're listening to a live concert you may hear some audio disruption.

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, a faulty piece of hardware, or even a dreaded ground loop. These steps will take you through some things to try to resolve the low droning hum and the high pitched static.

Tools You'll Need:

• A paperclip
• iPhone charging cable
• Access to a computer with iTunes installed
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Before You Begin:

• You must have access to a computer with iTunes installed.
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You must have this thing before you whatever.

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What is a Ground Loop

A ground loop in Surround Sound 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 Surround Sound System.

2. Determine and Fix What is Causing the Static, Hum, or Hiss

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 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.

1. Let's start by unplugging your subwoofer, if you have one, and see if the hum is gone. If the hum disappears after not using your subwoofer, there could be a fault in that device.
2. Try plugging the subwoofer into the same outlet or power strip as the rest of the equipment. Doing this prevents a ground loop. If after plugging it into the same outlet, you have no hum, you definitely had a ground loop.
3. 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.
   

1. 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.
   

1. If the hum, static, or hissing still persists after checking those devices, you'll need to disconnect each component individually and test them.
2. Unplug each speaker and test them separately. One of them may have the sound problem and need to be replaced.
3. Just remember, take your system down to its simplest level of connection. 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.

3. Check Surround Sound Cabling and Power

If your surround sound system is constantly humming or hissing at you there could be a short in the wiring causing issues.

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.

Adjust Your Power

Test your power outlet by plugging your device into a wall outlet you know is working, and not on a power strip or surge protector, to reduce the possibility of a short circuit. If that doesn't work try plugging your device into a different wall outlet.

Check Your Cabling

We want to make absolutely sure that all cabling on the rear of your A/V receiver is connected properly.

1. Speaker wires can be inserted into receivers in a few different manners. Making sure that the bare wires of each speaker cable are making good contact with the binding posts, poles or ports and has not come loose is very important.
2. If your A/V receiver uses binding posts or poles, ensure that the speaker wires did not slide out or come loose while tightening things down or moving the receiver in place.
   

1. If your A/V receiver uses spring-loaded clips, ensure that the bare wire is inserted fully and making good contact with each port. This type of connection can be prone to coming loose if wires are pulled on.
   

1. Some speaker wire is not color-coded for positive and negative, and may have text labels or only a line to indicate positive from negative. Ensure that positive and negative ends are connected properly at both the receiver and each speaker.
   

1. Aside from speakers, ensure that all other connections in the rear of the receiver are firmly and fully connected where they should be.
   

1. After making sure your connections are all firm and seated, check if any of the wires has been damaged or frayed. Not only will these cause your system to power cycle due to improper power supply, they can also catch fire. If you encounter a frayed wire, make sure it isn't plugged in before you remove it.