When you start a home theater, one of the biggest challenges you have is an echo. Echo comes from different sources, creating annoying reverberations in the process. If you have a surround sound system, there are many different ways to resolve such a problem.
To fix echo from a surround sound system, you need to look at the potential sources. Speakers that are out of phase, TV audio running parallel, center channel issues, and a problem with your home theater itself can be a major cause. To fix any of these issues need either rewiring, sound dampening, or adjusting speaker positions.
Are you looking to fix the echo from your surround sound? Check this in-depth guide for any of your echo issues. We’ll tackle everything you need to learn to resolve and remove as much echo as possible. Give it a look down below.
Echo should not be confused with muffled surround sound. Read my article on .
Understanding What Is An Echo
An echo is a byproduct of the mechanical nature of sound when it reflects at you. Sound, as we know, is a mechanical wave that travels through a medium, moving as a vector. The sound wave creates vibration when the particles of the medium interact with each other. Once they hit each other, energy moves through the particles, creating sound.
Once a sound reaches a medium, it creates different behaviors depending on the surface. Whether you have a hard surface, soft surface, distant or close medium, you’ll likely get a reflection and refraction. Reflection of sounds from surfaces is what we know as an echo.
A popular example of an echo is when you shout at a canyon. As we know, shouting towards a wide, open canyon results in a reflection of the same sound. Once the sound reflects off the walls of a canyon, you get an echo.
In a home theater, this can happen too. Speakers can have many different issues that result in an echo. Whether you’re listening to music or watching a movie, an echo can be annoying. If you have a surround sound system, it is more problematic.
Echo cuts off the immersion brought about by superior quality audio and video. The idea of surround sound is to make audio more realistic. Sound designers who work on movies and video games do so to create full immersion. Echo breaks this immersion by reflecting the sound you already heard.
Differentiating Echo vs. Reverberation
There’s a general confusion about the difference between echo and reverberation. There is a distinct fine line that differentiates both, and you might surprise yourself about it.
An echo is a singular reflection of a sound from a surface. When you send a sound wave, a single echo that reflects at you is an echo. Some even specify that echos should take more than 0.1 seconds before you hear it. This stipulation can be problematic if that’s the case.
Sound moves at a speed of 343 meters per second. If you stipulate that echo should take more than 0.1 seconds to reflect, you need a wall from a distance of at least 17m (343 m/s * 0.1 seconds = 34.3 m/s ÷ 2 = 17.15 m/s). A natural echo then is impossible to happen in an ordinary enclosed room.
This part is where the reverb comes in.
Reverberation is the reflection of two or more echoes across different media. Once the echoes start to overlap each other, they hold in memory, and there is no time delay. Reverb is a set of echoes that take less than a tenth of a second to hear.
Here is a video which explains the basic difference.
So, what does this mean? This detail means all reverberations are echoes, but not all echoes are reverberations. Most of the echoes that you hear from your home theater are likely reverbs. If you hear a single legit echo, that constitutes an audio delay.
Whether it’s an echo or a reverb, it’s still crucial to deal with them. Whether your surround sound is 5.1 or 7.1 doesn’t matter. No level of audio quality can immerse you if you experience echoes.
Apart from echoes and reverbs, there are also flutter echoes. Flutter echoes occur when two surfaces trap a sound wave, usually between speakers and a wall. When these happen, you can get a series of short sound signatures that translate into energy. This energy creates an audio disturbance, which becomes audible in the long run.
Flutter echo causes a delay between the audio output and potential video output. It can be a span of a few milliseconds, but that’s enough to make you see a difference.
How Does Surround Sound Work?
Now that we’re going to deal with issues in your surround sound let’s work out first how it works. So, how does surround sound work?
Surround sound, to put it at its basic form, is the use of multiple sound channels. Every channel goes through a different speaker positioned at various points in the room. Most of this audio comes from the source file, programmed, and decoded when played.
This process can sound simplistic, but surround sound offers a superior experience. Compared to mono and even stereo speakers, surround audio offers a richer experience. While mono only works one a single channel and stereo on two, surround works on either 5 or 7 channels.
For example, Dolby’s surround 5.1 uses a multichannel system of 5 speakers. It uses:
- Center channel
- Left channel
- Right channel
- Left surround channel
- Right surround channel
The usual formation has the center, left and right channel working on the front. The left and right surround channel position to the side or behind the seating. Another surround sound system is 7.1, which uses seven channels instead of five. These channels are:
- Center channel
- Left channel
- Right channel
- Left surround channel x 2
- Right surround channel x 2
Read my article on audio channels for more.
This expansion of the left and right surround channels allows for a richer surround experience. Two channels left and right surround, cover both the east and west of the seating position. The other two left and right surround channels cover the backside.
There’s also a subwoofer in both systems, represented by the .1 in 5.1 and 7.1.
Why Does Surround Sound Echo
So, what can be the cause of an echo if you have a surround sound system? Many potential issues on your system can cause a type of echo, which includes:
- Out of phase speakers
- Bad speaker wiring
- Bad audio dampening in the room
As you can see, these are crucial areas that can change the entire experience for you. If any of these fail, you can expect a bad echo from your surround sound system. The good news is that many of these issues are easy to handle as long as you know what to do.
Let’s take a look at how these issues happen.
Out Of Phase Speaker Setup Problem
Out of phase speakers are a common issue with home theater owners. It’s a problem with the wiring, which makes it a derivative of many speaker issues.
Here is a video which explains the basic problem.
Whether you perform internal wiring for your speakers or connect them to amps, it either moves in or out with an output signal. If you look at it from a single mono speaker perspective, this doesn’t matter. The speaker will still generate the right audio. Human ears are not even sensitive enough to hear the absolute phase from a speaker.
If you are using two or more speakers, polarity is crucial. It defines how they interact, so you need to get it right. This is where the issue of phasing comes in.
When a speaker goes out of phase, this means it has a wrong polarity. One speaker will move in, and another will move out when they’re out of phase. When one speaker contradicts the other, they can create an echo because of an audio delay.
If your speakers have the positive side of the wiring connected to the negative side, they go out of phase. To some, however, it’s hard to hear if the speaker is out of phase. It can sound like it has an echo on some tracks while on others, it won’t have it.
If you want to test if your speakers are out of phase, there are test tracks online that can confirm it. You can test on different frequencies to help you with the setup. The usual litmus test is to play an in-phase track and out of phase track. If your speakers are in-phase, the right track will:
- Play louder with a sine tone
- Render musical instruments playing in front of you rather than in your head
- Add body to the instruments instead of sounding disembodied
- Produce more bass
If you experience these issues, you likely have an out of phase speaker.
Resolving An Out of Phase Speaker
Resolving an out of phase speaker is as easy as changing the wiring of the speaker. Most of the time, speaker wiring uses a positive and negative connection. From the player system, you need to connect positive to positive and negative to negative. Connecting otherwise will result in out of phase speakers for you.
A turntable, DVD, or Blu Ray Player tends to have RCA connectors. These tend to stay color-coded for your convenience, usually red, black, or white. Yellow tends to go for video connections, but that should not matter as much.
If you use RCA connectors, all you need is to stay consistent with the color you use. Connect the same color wire to the same side on the back of the speaker. That should be enough to resolve any existing out of phase issues you’re experiencing.
If you’re not using RCA connectors, you’ll find that quality speaker cables will have a “+” and “-“ sign on the cable. Even without markings, you want to trace a cable end to end. By doing so, you’ll get to connect the same cable positive to positive, negative to negative.
While mixing the colors up should not be a problem, you’ll get echoes with surround sound. Why?
By going out of phase, you’re mucking the soundstage that the performance has. If you’re on surround, you’re paying extra for realism, immersion, and experience. By mixing the soundstage up and creating unnecessary echo, you’re changing the feel of the sound itself.
Fixing Surround Sound Speaker Wiring
Wiring is an essential part of surround sound. While it’s rare for you to get echoes with bad wiring, it happens to some. If you have bad cables and even defective ones, you’ll likely get the problem.
There are only a few hard and fast rules when wiring surround sound and all types of audio equipment. To many, wiring is a straightforward task that doesn’t need much correction. For some newbies, however, having to handle a good chunk of it can be confusing.
The first rule of audio wiring is to prevent the power cable from interacting with the audio and video cables. Electricity has its frequency that can create interferences with the audio. This interference can be anything, from some low-frequency humming to signal echo.
Many modern cables have electromagnetic shielding and are thick enough not to cause problems. If you’re experiencing such an issue, it’s best to change the cables if you have spares. There’s also the simple solution of doing proper wire management for your audio equipment.
If you can, it’s best also to use three-wire signal cables instead of two-wire cables. Three-wire cables don’t experience power hum and other interference and signal noise as much.
Another rule is not to loop any antenna cables if you use them. While twin-lead cables are old-school and are not in use these days, they can cause heavy interference. They can create a severe echo that will be problematic for your audio setup. If you have an old school setup that you use for your home theater system, make sure to move this wire away.
Understanding Bad Audio Dampening
One of the most crucial parts of owning a home theater is to use audio dampening measures for your room. As we know, echoes tend to reflect off different surfaces, and different surfaces create different echoes. Knowing how to deal with such surfaces can help reduce the echo from your surround sound.
Harder, smoother materials produce more distinct echo and reverberations all around. Why?
When two mediums differ a lot, sound reflection becomes more prominent because of the vibration. Hard materials like concrete can’t be any more different than air. It’s thick and nonporous, which reflects all the soundwaves instead of absorbing them. Once this happens, you can get the same audio reflected with no loss of energy, resulting in an echo.
Other materials that create echo include:
- Natural stone
- Thick hardwood
When this is the case, there are different ways to solve the echo issue that you experience. You would need to deal with both walls, flooring, and ceiling to cut down on any echo. To do so, you would need the proper setup.
Materials That Create Echoes
The simplest surfaces to deal with that create an echo are floors. Floors made of tiles, natural stone, and rock tend to create strong echoes and reverbs. Such surfaces can be a problem, and you should break up the echo as much as you can.
When you deal with flooring, the simplest answer is to add some carpeting. Carpet is not only thick and soft, but it’s also strong. Its loose fibers can absorb sounds easily, which cuts down a good chunk of echo from your surround sound.
The hardest surfaces to deal with are walls, which can be troublesome. If you own the home, it should not pose too much of a problem. If you’re renting, however, it can be an issue.
Modifying the walls of your rental home too much can be a cause of eviction. It’s also a serious waste of resources to install and dismantle everything when your tenancy finishes. We do have a solution to both problems.
Solving Home Theater Room Echoes
If you own the home, the easiest solution is to install acoustic foam panels. Acoustic foam is a thick, open-celled foam membrane that attenuates sound waves. By doing so, it breaks the mechanical nature of sound, absorbing it and dissipating it too.
Acoustic foam not only cuts down on the noise, but it also reduces a lot of echo waves. Its echo reduction capability is superior to most materials. If you need something cheap and easy for your home theater, you can also use carton egg crates. While carton egg crates don’t mute noise, it kills a good chunk of echo from the room.
Let’s assume that you’re renting, but you still want a decent home theater and surround sound. What can you do?
If you have the resources, the easiest way is to buy acoustic blankets. Acoustic blankets are cheap and easy, and at most, you would only need 4 to 6 of them. They come in different sizes and have grommets ready for installation.
When possible, populate your room with furniture. Add cabinets, sofa, tables, and lounges to the room to reduce the open space. The less open space you have, the less the vibration you get from your sound. Cut down on paintings and portraits with glass on them, as they can add to the echo.
For windows, it’s crucial to add curtains. Thicker curtains can muffle soundwaves and kill off echo. You want to make sure to cover window panes to cut on the echo.
The echo from your surround sound can come from many different sources. It can be anything from an out of phase speaker, bad wiring, or even inferior room acoustics. If that’s the case, there are quick solutions to each one.
With surround sound, you must resolve the echo as soon as possible. Not only does echo reduce your level of immersion, but it also dampens the intended experience. It’s best to invest in echo reduction options to get the best sound quality.
Are you working to improve on your surround sound? We know these solutions can help you handle any issue you experience. Try them yourself and we’re sure you’ll find a way to handle them.