How many Acoustic Panels do I need?

Acoustic panels enhance the comfort and function of every space, whether residential or commercial. They absorb sound and create a superior atmosphere. Acoustical panels lessen overall sound in the room, filter any outside sounds around it, and remove any unwanted noise or background sound inside the room.

We take pride in being the #1 source of information on all things acoustic. Our blog is listed in the top 40 soundproofing blogs on the entire internet. And we couldn’t do it without you. We value our readers and our favorite thing to do is answer your questions. Today, we have a simple, yet very important question from David:

Hi. Wonderful website! I was hoping you could answer a basic question: I have a “grand room” shaped like a trapezoid. The shorter wall (about 16ft.) is the exterior wall. The tall wall (about 25ft.) reaches the peak of the roof. The ceiling is wood. The floor is ceramic tile. The walls are drywall and there are lots of windows. The sounds echo terribly. I can make acoustic tiles, but I don’t know if I should hang them on the tall wall, short wall, or if I need them on both walls. Also, I don’t know how many I need. Can you give me some general instructions?

-David

The answer depends on the purposes of the space. Here, we will try to explain the various factors that influence the number of panels that you need. Let’s find out what is the right solution for your situation.

Size and Shape of the Room

Larger rooms tend to produce more noticeable echo and reverb. Sound bounces off a surface, producing reflections that can be either absorbed or bounced onto other surfaces. The larger the room, the longer the sound must travel between each of these bounces – adding up to a longer time delay before the sound waves dissipate.

The other important factor to consider is the shape of the room itself. High ceilings will increase reverb time considerably. Parallel surfaces, the like of drywalls or hard floors, give the room significant resonance. Installing acoustic panels will help you deal with these effects efficiently. 

Surface Materials in the Room

An important factor to consider is what kind of materials are used in the room. Is the floor carpeted, or do you have hardwood? Do you have concrete walls, or are they drywall? Hard surfaces reflect more sound which has a huge impact on the reverb time, while soft and porous textures absorb more sound, resulting in shortened reverberation time.

The objects inside the room also play an important factor. A fully furnished room complete with plush couches and pillows absorbs the sound into the materials – reducing echo effects. This can lower the number of acoustic panels that you need inside that room.

Purpose of the Room

Acceptable levels of room reverberation vary by the purpose of the room – there is no one-size-fits solution. Do you want a home office or a home theater? Maybe you want a home recording studio?

The purpose of the room influences how much sound you want to absorb and at what frequencies. If you only need to absorb mid and high frequencies, you can go with the thinner panels. Thicker noise-canceling panels absorb low frequencies, as well as high frequencies. Generally, if you want to control the background noise, absorbing the low frequencies is not needed. If you want to use the room for recording or as a home theater – control of low, mid, and high frequencies is a must.

Adding too many acoustical panels in spaces like home theaters or home offices will reduce the reverberation too much and make the space sound “dead”. This isn’t usually desirable in those spaces but maybe for recording studios.

Type of Acoustic Panel

The type of acoustic panels greatly affects the sound quality. You have to take into account panels size, shape, and material. Each of our sound-absorbing panels will have a Noise Reduction Coefficient (NRC) which helps indicate how well the panel absorbs sound. NRC ratings usually range between 0 and 1, with a higher NRC rating generally providing better sound absorption. You can read more about NRC on our blog.

The panels you use are highly dependent on the goals that you are trying to achieve. At Acoustical Surfaces, we have various options for your soundproof needs like our Echo Eliminator™ echo reduction panels, made from bonded acoustical cotton a quality, cost-effective approach to sound control. 

Positioning the Panels in the Room

To think about the placement of the panels, you need to think about the intended use of the space. Why is this important? The position of panels can make a difference depending on various factors such as the use of the space, and the types and locations of sound sources. 

Take for example listening spaces such as home theaters, recording studios, etc. You probably get how big the importance of crystal clear sound in these rooms. So it’s important to consider the position of the listener and the position of the sound source(s).

It’s generally recommended to place diffusion/absorption panels at first reflection points. 

So where to start? The easiest ones to treat tend to be on the sidewalls, if you want to play safe it is always a great choice.  First or early reflections arrive at the ear first, and the strongest reflections are following, causing the most destructive interference at the listener’s ears. 

Other places to put panels in listening rooms are the ceiling, corners, and the back wall to deal with more first reflections, and room modes. To find out more, check this image showing common placements. 

What about the other types of spaces?

For spaces like restaurants, offices, more common areas, where the sound sources tend to be people speaking and the sound tends to be more diffuse, then it’s a little less important to worry about placement.  

You still wouldn’t want to place all the absorption in a restaurant on one wall.  You need to create an even sound environment for all your customers. 

If you decide to go with one wall -someone on the opposite side of the restaurant would have a different acoustical experience than one near the wall with panels. 

You have to find the balance of where space allows you to place panels, and still try to somewhat evenly distribute panels

So, how much do I need?

Over the years, we have put together a simple equation that we have had plenty of success with. This equation is used to “take the edge off” of a room and make it much more usable. When dealing with listening rooms or recording rooms, it gets much more complicated. In this case, though, we are very comfortable stating that it will make a significant difference in the sound quality of the room.

You can use our robust formula:

• Cubic Volume of the room x 3% = square footage of product

• Height x Width x Depth x 0.03 = Sq/Ft

You don’t have to be spot on, so average the ceiling height and go from there. This simple calculation that doesn’t even need a calculator works wonders for the acoustical qualities of the room. Keep in mind that these are the numbers for absolute minimum coverage for average users. 

Conclusion

We hope that this article helps shed some light on the number of panels needed. If you are still in need of a professional solution, we can help you make the right decision. Call our helpline at 1-800-854-2948. We are here for you.

2 Comments

1. Mitch

   10/05/2011 at 12:34 pm

   Thanks for the rule of thumb! I have a critical listening room that is 30’L x 15’W and 8’H. The stereo speakers are along the long wall. The room is comprised of hardwood floor, windows, and bare drywall, inlcuding the ceiling.

   I am interested in your dBA panels as it looks like I can just glue them on the drywall. Using the calculation, it appears I need 108 sq ft of product. Is that right? Also, how do I choose between the 1″ or 2″ thickness?

   Finally, where should they be placed? I presume the ceiling and back wall where the stereo is pointing? How far apart do I install the panels from each other in order to be effective?

   Many thanks!

2. Ted W

   10/07/2011 at 8:47 am

   Thanks for the Comment, Mitch.
   We may want to talk a little bit about a critical listening room as the “rule of thumb” is really a better formula to “take the edge off” of a room and simply reduce the overall reverberation time. A critical listening room is likely going to need a more room-specific approach.

   Would you be able or willing to send me a sketch of the room showing the general location of everything and maybe a digital photo or two so that I could have a look at it and help lay out a plan of attack for you?

   The dBA panels may or may not be the best for you, that is going to depend on the room itself. Most of our products can be glued or mounted directly to the wall. The “best” approach may be to use a few different products in specific locations.

   If you are able to send me a bit more information about the room, please use [email protected] and include your contact information.

   Thank you!!!
   Ted