If you’ve ever been in a recording studio, one of the things that you will notice are the treatments that line the walls. Not only are these panels soft to the touch, but they also provide an invaluable support in recording. This makes up an acoustic treatment, which channels the maximum acoustics from a recording studio. Most acoustic treatments in recording studios are set up by professionals. However, with the right design and careful planning, others can create and install them for their own studio setup.
What Is an Acoustic Treatment?
To begin, it is important to understand how sound travels to understand the role that acoustic treatments play. Sound travels in pressure waves through the air, and when it meets a hard surface it reflects and echoes or reverberates.
In other words, an acoustic treatment covers the recording studio with panels that improves and controls the acoustic behavior. This can be helpful if the space is intended as a home theater, listening room, control room, or a studio. Creating an acoustic treatment means first understanding basic acoustic behavior and how it works with most rooms.
First, sound that’s made in a room projects outwards in all directions. The majority of this sound reflects, which impacts and bounces off of other surfaces in the room. Additionally, the remainder of the sound travels in a straight line to the microphone, which is known as direct sound. The reflected sound has potential to change the tonal quality of the original sound. As a result, it is important that an audio engineer understands how sound absorbs and diffuses.
Absorption traps sound waves and allows for the direct sound to be picked up by the microphone. In contrast, diffusion scatters the sound so that none of it gets trapped. Trapped sound also cancels out frequencies while it boosts some, which also throws things out of balance.
Ultimately, the dimensions of the room magnifies these issues. Unless a room is constructed specifically for a recording studio, it likely does not have the dimensions that are necessary for tonal quality.
Creating an Acoustic Treatment
Creating an effective acoustic treatment depends on the desired acoustic behavior for the room and the budget. Acoustic treatments can be made with different materials.
Foam is the main component of acoustic treatments. This is because open cell foam prevents sound from bouncing off of hard surfaces. It also limits sound from other rooms near the studio. Depending on the acoustic treatment, these types may have thick ridges or can be thin slabs with perforations.
This type is used more for flat acoustic panels that would be set up in front of musicians. Fabric can also be employed in diffuser boards. Some studios use this to add a bit of flair to their live rooms or control rooms.
Additionally, fiberglass is the base panel for commercially produced acoustic treatments. It’s a rigid surface that an audio professionals affixes foam or fabric to when they create their own acoustic treatments.
Wooden Acoustic Treatments
Wooden acoustic treatments are normally perforated to diffuse incoming sound waves. These can be made using reclaimed wood as a sustainable alternative to foams. Acoustic treatments that use this sort of wood tend to be the choice of those with smaller home recording studios.
Different Types of Acoustic Treatments
Acoustic treatments come in various types to cover different parts of a space, including bass traps, diffusers and acoustic panels. The role of each of these are as follows.
Bass traps are highly important acoustic treatment elements. This panel absorbs the bass frequencies. For example, these can be more audible in reflected sound, but they also handle mid and high ranges as well. This is because of their porous construction.
Most recording studios use bass traps in the corners of a room. Additionally, a recording studio uses bass traps from floor-to-ceiling if the space permits. A bass traps are thicker and serves as corner pieces overall. In contrast, small scale studios may choose to use bass traps if they are unable to get full coverage panels.
Acoustic panels tend to be thinner and cover more surface area while using less foam material. These panels also tend to work well with the middle range of frequencies in reflected sound, and are typically hung from walls or the ceiling.
Diffusers tend to be in panel form as well. As a result, this panels handles the lower frequencies well. In contrast, a recording studio may choose to forgo them. One reason for this is if they plan to utilize bass traps and acoustic panels. They are normally flat with patterns cut into them to handle the trapped sound better.
Placement of Acoustic Treatments
After the acoustic treatments are obtained, a professional places them throughout the studio space. This process actually begins during the walk-through of the studio. An audio professional goes through the room and claps their hands as loud as possible–this is to find the studio’s “sweet spot”.
Finding the “Sweet Spot”
As they’re doing this, the audio professional listens to every reverberation. This is so that they can differentiate between two situations – being able to hear a harsh ringing sound with a metallic tinge, or hearing a gentle reverberation.
The former scenario means that there needs to be an extensive acoustic treatment that provides more absorption. The latter scenario means that you’ll need fewer acoustic treatments in the space. The main goal is to locate the “sweet spot”. This location will be the primary point where all of the equipment will be set up.
Installing Acoustic Panels
Once an audio professional chooses the studio’s sweet spot, they install the first part of the acoustic treatment. In this case, this means the bass traps. As mentioned before, bass traps go in the corners of the recording studio.
There are also standalone bass trap panels that some audio professionals have to set in front of performers, but they get arranged after the primary setup. Next up are the acoustic panels, which get installed on the walls. It is important that the professional arranges them in a way that accounts for reflection. If there’s a limited amount of acoustic panels, audio professionals will install them in a checkerboard fashion to minimizes bounce.
Lastly, the diffusers will be installed in the ceilings and the upper part of the live room where there is free space. This is so they can handle the initial reflection of sounds better. They also tend to work better in larger rooms since there is more surface area to cover to go with the high ceilings.
Final Thoughts on Acoustic Treatments
Acoustic treatments are commercially available in separate pieces or in full kits. Some who have home recording studios don’t have the budget to obtain these full kits as mentioned before, and there are DIY methods to substitute for those missing parts. In this regard, it’s best to instead focus on other alternatives such as reflective filters for any microphones and working on emphasizing the direct sound by using dynamic microphones to offset the reflected sound.
Acoustic treatments will help an engineer or producer achieve cleaner recordings with a more pleasant sound. While you can still get sound bleeding out of the studio or from adjacent rooms, a proper acoustic treatment will make a staggering difference when recording.
Want to Learn More?
Acoustic treatments are an important part of any recording studio. For that reason, it is important than an audio engineer understands how to utilize them in a recording studio. If finding out about this aspect of audio production intrigues you as a part of working in the music industry, take a moment to check out IPR and the training that they provide.
Contact us today to learn more about the audio production and engineering program and starting a rewarding career in the music industry.