You are meeting a friend for coffee at a new place in town. It’s decorated with concrete floors, brick walls, and steel plating on the ceiling.
While you and your friend try to have a conversation, you can barely hear each other over the other patrons and the baristas. The liveliness of the space is overwhelming and stressful.
If your business, school, or church sounds similar to this, you should consider acoustic absorption. It will help tame the sound in your space and make it less chaotic and more productive.
If you’re looking for information on acoustic panels, you’ve come to the right place. Read on to learn more!
Basics of Acoustic Absorption
Before you decide on what acoustic room treatment you need, you need to understand some basics of acoustics and acoustic absorption. Different acoustic phenomena cause different issues.
The Frequency Spectrum
The range of human hearing goes from 20 hertz to 20,000 hertz. The lower the hertz, the lower the frequency. Lower frequencies have more energy and larger waves.
Low frequencies are what we consider “bass.” Bass frequencies tend to build up very quickly in a space and go through walls and other materials much easier. This is because they have more energy than higher frequencies.
Mid-range frequencies start at about 200 hertz and go to around 1500 hertz. These are where most of the acoustic energy for sounds is found, such as human voices and musical instruments.
High frequencies cover everything else up to 20k hertz. These are where we get articulation, such as consonants in human speech or the attack of an acoustic guitar strum.
Standing waves are an issue that primarily happens with the low end in a room. This is when low frequencies are reflected back onto themselves. It results in a muddy, boomy sound.
Standing waves can be treated with special acoustic panels called bass traps. These capture the bass frequencies and keep them from reflecting back.
Flutter Echo and Comb Filtering
These two acoustic phenomena are very similar and can cause lots of issues in a room. These usually occur in the higher range of frequencies. Both can be treated with acoustic wall panels.
Flutter echo occurs when sound bounces between two parallel surfaces. This creates an “echo” effect that sounds flanged.
You can hear this for yourself by standing in a hallway and clapping your hands. It will sound metallic and strange.
Comb filtering is when frequencies are bounced back and forth between surfaces. But instead of echoing, they collide and cancel each other out, leading to strange distortions of the sound.
The primary goal of acoustic treatment is to absorb or deflect a large portion of sound in a room. This prevents a buildup of noise across the audio spectrum.
Some reverberation, however, may be desirable. Spaces such as church worship halls and auditoriums will strategically use acoustic treatment in problem areas while leaving other surfaces to reflect sound naturally.
Acoustic Absorption For Each Frequency Range
In order to properly apply acoustic room treatment, you will need to match the “intensity” of the treatment to each problem frequency range.
Low frequencies require thicker materials, due to their higher energy and larger waves. This includes materials such as Rockwool, dense and thick acoustic foam, and building materials such as cinder block.
Mid-range frequencies are usually the most difficult to treat, but also tend to cause the least amount of problems. These are usually handled with diffusers, which we will discuss in the next section.
High-range frequencies can be easily absorbed with acoustic panels made from foam or other absorbing materials. They can also be diffused.
Determining Your Acoustic Room Treatment
If you have a room with bad sound, it may be tempting to just throw as many acoustic treatments as possible at the problem. However, this is not a wise approach.
Creating too “dead” of a space can make it seem unnatural. Our brains are used to a certain amount of reverberation.
Treating your space on your own may not give you the results you are looking for. It is difficult to identify issues such as standing waves and comb filtering without specialized knowledge and equipment.
A professional audio engineer can help assess your specific needs and recommend the proper acoustic panels. This will not only give you the best sound but also save you money.
Types of Acoustic Panels
Let’s take a look at the different types of acoustic panels available on the market. Most spaces use a combination of different types of acoustic treatment. This ensures that all the problem areas are taken care of.
Wall panels made from acoustic foam or other absorbing materials are the most common and recognizable form of acoustic absorption. They are relatively inexpensive and can be quite attractive as well.
However, basic wall panels only control issues with high frequencies, so keep this in mind when you are shopping for acoustic treatment panels.
Bass traps are specially-designed wall panels that are much thicker and denser. This allows them to absorb lower frequencies. They can be expensive but are very effective when placed correctly at standing waves in a room.
Ceiling panels are very similar to wall panels but come in several different varieties. Drop-down ceiling tiles are very popular, but some spaces use a combined diffuser/absorption panel that hangs vertically.
Diffusers are different from absorbing panels. These are designed to reflect and scatter frequencies. This prevents them from reverberating and building up in a room.
These can be very useful if you want to keep the “liveliness” of a space, without creating a lot of reverberation and nasty flutter. Diffusers are available for both walls and ceilings.
Benefits of Acoustic Treatment
There are many benefits to using acoustic panels in a space. Acoustic absorption can give you better intelligibility, reduce stress, and improve hearing safety.
If you are looking for professional audio/video assistance for your business, school, or church, we are here to help. We offer a wide range of services, including digital modeling of your space and full audio system programming.
Please feel free to contact us at any time by emailing firstname.lastname@example.org or call 800-650-5378. We look forward to working with you!