RangeOfSounds.com is reader-supported. We may earn a small commission through products purchased using links on this page.
When it comes to recording audio in a room, there are many factors that come into play which can affect the quality of the sound that is picked up.
Echo is one of the main drawbacks of having a bad or non-treated room. In terms of recording, this will create unwanted artifacts, muddiness and possibly even comb filtering. Here I will talk about what causes these problems and how they can be solved within your own room or recording studio.
So, What is Echo?
Echo is the reflection and delayed hearing of a sound wave that bounces off nearby surfaces. When you speak into a microphone, sound waves bounce off of nearby walls and reflect back into your microphone creating a possibly unwanted echo. There are certain factors that make an echo more prominent in rooms.
Nullifying the echo
One of the first things to look at when dealing with echo is the shape and size of the room you are recording in. Large rooms will increase the chances of creating echos when generating sound within. The same goes for room shapes that leave great open areas.
One great way to reduce echo would be to make your room smaller, though it’s an expensive option. So here are some other ways that you can greatly reduce echo within the room you have already.
Acoustic Foam Panels
The general idea for removing echo is to introduce surfaces and materials that can disperse sound waves quickly, which stops the echos from returning to the microphone. One cheap and very effective way for soundproofing a room is to use foam panels; giving you these two benefits:
- Their softness is a great dissipator of high frequencies, which get absorbed into the material as opposed to reflecting off.
- They are designed to have irregular surface angles. This means that when incident sound waves hit the surface they will diffuse instead of reflecting. The foam panels greatly decrease the power of sound waves and further reduce the chance that sound waves will reflect back into your microphone.
How Do We Fit Them?
After you purchase your acoustic foam panels you will need to think about the placements within your room.
You do not need enough to cover the entirety of every wall of your room. They will be ideally positioned in the center of your side walls and ceiling, as this is where sound waves are likely to bounce. If you do find that the panels have reduced the echo, but not as much as you may have wanted, then consider adding a few more panels around the edges.
Bass traps are very similar to acoustic foam panels, however, bass traps focus on the lower end of the frequency spectrum. Now, the name is misleading as they don’t actually “trap bass” – they are absorption devices. They work by turning the energy absorbed from sound waves into heat.
As they focus on the lower end of the frequency spectrum they may not always affect your microphone recordings but are great to help balance out the low end. Which in turn, prevents standing waves that often occur in those places.
What Are Standing Waves?
A standing wave is created by the interference of two different sound waves. This creates moments of nodes and antinodes. Nodes are points of no movement whilst antinodes are points of movement in the wave. These are amplified in lower frequencies where they are more noticeable.
If you would really like to go the extra mile with your absorption, there are also these bass traps which cover all three edges of a room corner.
If space allows for it, you can add a microphone shield to your setup which is a much closer proximity method of blocking out unwanted echoes and artifacts. They tend to be crescent-shaped and are filled with acoustic foam. They are placed only a few inches away from the microphone on its opposite side.
On their own, they may provide a little assistance in reducing the echo into a microphone but are best used alongside other methods listed here.
Shields come in slightly different shapes and sizes. If you have a larger or taller microphone you may want a taller shield to ensure the isolation. You can use shields which are more crescent-shaped as mentioned earlier. Here is one for example:
This shape is even greater than crescent which will give more isolation. Do remember, these are better used in parallel with other methods, as using shields alone may not be sufficient to prevent echo from making it onto the recording.
A great way to reduce echo in a room is to add more furniture and other soft objects to it. As mentioned before, the more open space there is in the room, the more opportunity for waves to spread out and reflect.
If your room has wooden or otherwise smooth flooring, this will be a natural environment for reflection to take place. If installing a carpet is not an option, there are other, simpler ways to create more softness in the room.
Rugs are a quick way to add a layer of softness to your room, helping to further decrease the chance of reflection when recording.
A shaggy rug is a great kind to use in this situation as its texture is soft, thick and has a large surface area, which are all important factors in reducing that echo.
Sofas are another sizable object that can be an easy addition to a room, creating more absorption and diffusion of sound waves.
Even a duvet can make an effective sound wave absorber. If you can find a way to hang some around your room to form an isolated box you will surely avoid any potential echo.
In an untreated room, echo can and will run rampant through all of your microphone recordings. Unless that natural echo is something that you desire then it is most paramount to treat your room via the above methods in order to remove or minimize the effects the room has on your recordings.
If you take all of the methods listed above and put them into action, you will have a high-quality acoustic treated room. You will not experience echo that could be of disruption to your recordings. If you find that you could do with some more cushioning in the environment then don’t hesitate to add more, in fact, you can check out our blog on how to build your very own vocal booth!
Finding the balance between a “Live” and “Dead” room is important. A room that is “dead” could result in an unrealistically dry recording if what you strive for is an airy, natural sound.