Posts Tagged acoustical materials
Big vs. Bigger: 2′ vs 4′ Acoustic Diffusers
Posted by Acoustics First in Diffusion, Product Applications, Products on December 16, 2025
A couple common form factors in acoustics are based on building material sizes. Ceiling grids are a common place to install acoustic devices, and you will find that many are built to either work in a 2’x2′, 2’x4′, or 4’x4′ ceiling grid installation. This makes sense, but did you know that these devices also perform differently in some cases due to their dimensions? This is especially true with acoustic diffusers.
When you’re tuning a room—whether it’s a studio, theater, rehearsal space, or even a high-end listening room—acoustic diffusers are one of those rare tools that improve clarity without taking the life out of the space. Designs like the Double Duty Diffuser, Pyramidal Diffusers, and Quadratic Diffusers all share that same mission: redistribute sound energy so your room feels open, natural, and honest.
But while they may look similar in concept, their size changes the game. A 2’x2′ panel and a 4’x4′ panel both diffuse sound, but their effect—especially in the low-frequency and low-mid ranges—can be very different.
2’x2′ Diffusers — Compact Control
2’x2′ units are the most modular diffusers in the lineup. Their smaller footprint makes them ideal for:
- Breaking up mid and high-frequency reflections
- Treating small and medium rooms
- Sitting comfortably in grid ceilings or tight wall spaces
Because of their size, 2’x2′ diffusers don’t interact as much with the low-frequency energy in a room. Bass waves—being physically large—tend to wrap around smaller objects. The result? Excellent clarity improvements in the mids and highs, with a very predictable diffusion performance. The Double Duty Diffuser and Pyramidal diffusers have been a standard in breaking up planar surfaces for decades. While their diffusion in low frequencies is limited at this size, the air cavities do help control some upper bass frequencies through absorption.
The tuned mid frequency effects of the 2’x2′ quadratic, and the smooth performance of the Double Duty or Pyramidal diffuser are perfect for control rooms, edit rooms, drum booths, and anywhere you want accuracy without sacrificing sparkle.
4’x4′ Diffusers — Where Diffusion meets Bass Control
Now we get to the big ones.
A 4’x4′ diffuser is similar in concept to its smaller relatives, but the scale moves it into a different acoustic category. At this size, diffusers begin to influence longer wavelengths, which opens the door to something smaller diffusers often struggle with…
Low-frequency interaction
Large diffusers present enough depth, volume, and surface area to affect the bass spectrum. The extra size creates cavities which are tuned to reduce bass, and they have surfaces large enough to redirect those lower frequencies.
- Break up standing waves in the low-mid range
- Reduce modes and nodes common in rectangular rooms
- Add a sense of openness to the bass field
- Prevent buildup behind listening positions
In other words: same diffuser concept, very different low-end behavior.
Wide-area coverage
A single 4’x4′ panel can modify a huge portion of a wall, creating an even, spacious character that feels less like “treatment” and more like a room that’s naturally well-behaved.
These panels shine in larger studios, live rooms, and worship spaces—anywhere you need diffusion that reaches deeper into the frequency spectrum – and can break-up large, flat, specular surface reflections, which are responsible for flutter, echoes, bass buildup, and long reverb times.
Which do you need?
There are two main factors in the decision: space and performance requirements. In certain environments, it’s impractical or impossible to install large 4’x4′ or larger diffusers; It also may not be the best solution – even if it may appear to be on paper. While a single, large barrel diffuser may appear ideal, you may not have enough physical space to allow the diffusion to develop – where several smaller diffusers would be the better solution.
In short, your physical space and acoustic conditions will dictate which size elements will give you the most benefit in your environment.
Eight very different 2′ x 2′ sound diffusers.
Posted by Acoustics First in Diffusion, Product Applications, Products, Recording Facilities on June 30, 2025
Acoustics First® has maximized the idea of adaptable designs. One of the most common modular architectural elements is the 2′ x 2′ ceiling grid. While standard, fiber ceiling tiles have their uses, specialized acoustic environments require higher-performing materials – for both absorption and diffusion. While Acoustics First® excels with its Sonora® and Cloudscape® Ceiling tiles, today we are going to focus on the wide range of 2’x 2′ diffusers that have been developed over the several decades.
Sound diffusers in a 2′ x 2′ format have several advantages, other than just being placed in a ceiling grid to help diffuse the ceiling. They integrate well on walls and in arrays, where they can help break up large flat surfaces and help minimize flutter and standing waves from parallel surfaces. While they provide many different aesthetic options, there are also many different functional types of diffusers available in this form-factor to address different acoustic issues, from flutter, bass issues, targeted frequency absorption, and geometric scattering. Let’s look at some of these devices and their uses.
Geometric Diffusers.
Geometric diffusers have been around a long time. These devices break up large flat surfaces and redirect or “scatter” those reflections in different directions. They work great in environments where you need to redirect acoustic energy in a predictable way, and redistribute a specular reflection over a wider area. In a 2′ x 2′ size, you can also get a fair amount of bass absorption, due to the large cavity behind the geometric shapes creating a space that can be stuffed with absorbent material to tune it.
Quadratic/Mathematic Diffusers
Mathematic diffusers are devices that use specific calculations to design their size, shape, and structures to effect their performance. A common type is called the Quadratic Residue Diffuser (sometimes called a Schroeder Diffuser, after its pioneering inventor, Manfred Schroeder). This type uses a Quadratic Residue Sequence that optimizes uniform sound diffusion at specific design frequencies. There are different ways to implement these designs, but two common designations are based on their diffusion patters – 1D or 2D. A 1D Quadratic diffuser mostly spreads energy in one plane, and a 2D provides a hemispheric pattern.
Organic Diffusers.
Organic diffusers are a variation on the classic mathematic diffusers which use different mathematic functions to optimize the diffusion further by creating a smooth transition. Once such method is called Bicubic Interpolation. Instead of having the math restricted to having blocks at certain heights, the interpolation bridges these heights using a function that provides a smooth transition to the next target height. This transition creates unlimited resolution in the frequencies within it’s functional range, providing expanded uniformity throughout its range, and increasing its capabilities. As different frequencies are affected differently depending on their wavelength – the organic diffusers have no hard edges to define their pattern and look differently to different frequencies and energy from varied sources.
These diffusers all have the ability to be used in different types of installations for different reasons. Many of these diffusers are mixed and matched in the same room. You will see these on the walls or ceiling, and placed in different locations. There are rooms with Double-Duty diffusers for low frequency control, Model C for Mids, and Model F for flutter, while other rooms may have Aeolians™ on the rear wall and Model C’s and Model F’s to control the ceiling.
Keep in mind, these aren’t even all the diffusers we have available, these are just the ones specific to the 2′ x 2′ format. The Aeolian™ has a 1′ x 1′ version called the Aeolian™ Mini. There are flat panel diffusers that are hybrid absorbers and diffuser like the HiPer Panel® and the HiPer Panel® Impact. There are even large format versions of the Double Duty™ diffuser, Pyramidal, and even the Quadratic Diffuser.
For more info about these diffusers, read some of our, “Similar, Yet Different Series,” where we go into more detail about our products… and how some of these are similar, yet different!”
If you have any questions as to which products you need to optimize your space, reach out to Acoustics First® and we can help you find which products will be best for your application. Remember that Acoustics First’s® full line of sound diffusers are all made in the USA, with many available in stock for quick shipping.
Eat with your Eyes (and Ears): Acoustic Treatment for Restaurants
Posted by Acoustics First in Absorption, Products, Restaurants on March 21, 2025
When evaluating a restaurant, guests will often look at four factors: food quality, service, price point and atmosphere. The first three are fairly obvious in terms of how they influence the customers satisfaction, but the link between atmosphere and guest satisfaction is a bit murky.
Atmosphere is a sort of “catch-all” term for the various room and design elements that contribute to the overall experience of the patrons. “Atmosphere” is usually associated with visual elements, like lighting, table setting and decorations, but “atmosphere” can literally refer to the air in the room (is the restaurant properly ventilated, are there distracting smells from the kitchen?) or more functional/operating elements like the layout of the tables and, our focus in this article, sound management.
Sound Management – How many times have you been to a busy restaurant that is so loud you can’t hold a conversation with those at your table? It’s difficult to understand speech when background noise and reflections from other sources cover up new information. This causes patrons to elevate their voices to be heard, further exacerbating noise level issues.
Studies show that patrons spend more time and money at restaurants that properly address sound management, ensuring their guest don’t feel overwhelmed at peak hours. Key considerations include:
- Background music: Choose music that complements your restaurant’s concept. Adjust the playlist and volume based on the time of day and desired energy level—soft jazz for a relaxed dinner or upbeat tracks for a lively lunch.
- Comfortable conversation levels: Keep music and ambient noise at a volume that allows guests to speak without straining to hear each other. The right balance creates a welcoming buzz without becoming disruptive.
- Consider layout impacts: Open kitchens, high ceilings, or closely packed tables can amplify noise. Think about incorporating design features like partitions and high booths to help “break up” sound that is traveling from table to table.
- Acoustic design elements: Sound will build up most in spaces that have a lot of hard/reflective surfaces. Use sound-absorbing materials like acoustic panels to reduce reverberation/echoes and create a more intimate atmosphere.
Tone Tile Panels – In restaurants, it’s especially important to minimize visually obtrusive acoustic treatment so it does detract or conflict with the carefully constructed aesthetic of the dining room. Tone Tiles are a perfect solution for restaurants that require “invisible” sound absorption as they can be field or factory painted to match the wall or ceiling color precisely. They also have a white, lightly textured surface that resembles drywall (Tone Tiles can be used as projector screens). Keep in mind, the more you paint an acoustic panel, the less sound reaches the absorptive substrate. We recommend light passes with water based paint to ensure the surface of the panel remains as acoustically “transparent” as possible
Silent Picture Panels – Another popular treatment option is our Silent Picture panels. Silent Picture panels can be wrapped with customer supplied artwork, images or branding. Restaurants love the double utility of full-color images and premium sound absorption.
Can’t I just put foam under the tables? We do not typically recommend acoustic material underneath restaurant tables. Treating the underside of tables will only “take the edge” off overall sound buildup, primarily attenuating sounds produced below the table (shuffling feet, chair slides, etc.). Sound absorptive treatment is much more effective when in the direct “line of sight” of primary sound sources. Also, installing acoustic foam or felt under tables, where it is likely to be picked at or possibly soiled, present durability and sanitary concerns.
We’ve all heard the expression that we “eat with our eyes”; if the meal is not appealing to look at… it is less pleasing to eat. However, we also “eat with our ears”; if the environment is not conducive to comfortable conversation, then the customer will leave with a bad taste in their mouth, even if the food quality and service is exceptional.
Acoustic Treatment in the 1920’s – A look at the Guardian Building
Posted by Acoustics First in Absorption, Offices, Uncategorized on January 14, 2025
The bank wanted the building be a “show-piece” and communicate its principles of “security” and “fidelity” (remember, this was at a time before the FDIC), to impress customers and convince them to store their valuables at their bank. Incredibly, the building was completed in just one year; construction began in 1928 and finished just before the Stock Market Crash of 1929 (so much for fidelity).
Head designer Wirt C. Rowland had far from a subdued vision for the building. Blending Native American, Aztec, and Arts & Crafts designs, Rowland wanted to make an indelible impression on anyone who walked in. He said “We no longer live in a leisurely age…the impression must be immediate, strong and complete. Color has this vital power.”
Colorful, luxury materials grace every surface of this building. Italian Travertine marble was used for steps and wall surfaces, contrasting with deep-red Numidian marble imported from Africa. Brilliantly colored tiles fill the lobby’s vaulted ceiling, and a massive multi-colored mosaic adorns the vestibule wall. Monel metal was used in the large ornamental gate dividing the banking hall and main lobby, supporting a pair of Tiffany & Co. Glass clocks. Even the office corridors and restrooms are lined in a Tavernelle marble from Tennessee.
Obviously, these beautiful materials are also extremely sound reflective. Having worked on similar buildings, Rowland understood the need for acoustic treatment in the banking hall as there would be hundreds of customers, tellers and their managers trying to conduct important business in this large, cathedral-like space. If they used the same ceramic tiles they used on the ceiling of the lobby, conversations would be drowned out by a cacophony of typewriters. In lieu of the tiles, the banking hall has an incredibly appointed, intricate system of stretched canvas over wood frames backed with sound-absorbing horse hair. The canvas was hand painted with real gold and silver and requires regular maintenance. In fact, the same Italian family that made the ceiling nearly 100 years ago has been caring for it ever since!
I recently had the pleasure of touring the Guardian building, and walking through the Monel gate from the lobby to the banking hall, you can hear the difference. Though the banking hall is much larger, it feels much more intimate and comfortable, in large part because of the ceiling. Although the horse hair and canvas materials may not meet fire code today, modern stretched-fabric acoustic assemblies owe a lot to this sort of early innovation.
The Guardian Building is a symbol of creativity and achievement. Designed for the future, it is no surprise that Rowland’s masterpiece still dazzles and inspires visitors to this day.
For more information on the Guardian Building’s long history, visit https://www.guardianbuilding.com/history
Acoustical Considerations for Classrooms
Posted by Acoustics First in Absorption, Articles, Classrooms, Product Applications, Products, School & Educational Facilities, Teaching Rooms on September 19, 2024
Poor classroom acoustics has long been the invisible problem that has the farthest reaching implications for learning. Excessive noise and reverberation degrade speech intelligibility, resulting in reduced understanding and therefore reduced learning. In many classrooms in the United States, the speech intelligibility rating is 75% or less. That means, in speech intelligibility tests, listeners with normal hearing can only understand 75% of the words read from a list. Imagine reading a textbook with every fourth word missing. Wouldn’t that make comprehension near impossible? Fortunately, poor classroom acoustics can usually be remedied with some basic knowledge and commercially available treatment. But before getting into specific treatment, let’s go over some basic acoustic principles.
Noise
Obviously, it’s difficult to understand what the instructor is saying when there is a lot of naturally occurring noise in the room. A glut of factors can be considered noise sources, including HVAC “rumble”, traffic outside the building and students moving in their chairs. These sources contribute to a “noise floor” that makes understanding speech very difficult. Since there is no one “cure-all” for an excessive noise floor, it is often best to seek the assistance of a professional acoustical consultant to properly diagnose and find a solution to these issues.
Reverberation: Undesirable vs Useful Reflections
When not attributed to a noise issue, the culprit of poor classroom acoustics is often excessive reverberation. In simple terms, reverberation is the sound energy that remains in the listening environment as a result of lingering reflections. As mentioned before, these reflections can easily interfere with speech intelligibility. As you may have experienced at some point, it can be difficult to understand what is being said when reflections from old information cover up what is newly spoken.
The reverberation time (RT or RT60) is used to determine how quickly sound decays. The RT is dependent upon the volume and surface materials of a given room. Large spaces with hard materials (tile, drywall, etc.) have longer reverberation times, while small rooms built with “softer” materials sound more “dead”. Ideally, classrooms should have relatively short RT’s, somewhere in the .6-.8 second range.
A long reverberation time is not the only factor that should be considered when treating a classroom with poor acoustics. Flutter echo is a particularly significant problem when it occurs between the side walls at the front of the classroom where the teacher is speaking. This condition can be heard as a “ringing” sound (when one claps) as the sound rapidly bounces back and forth between two parallel walls. Flutter and other discrete echoes are considered “undesirable reflections” and should be controlled with absorptive or diffusive materials.
Not all reflections are bad though. There are “useful reflections” that reinforce spoken word, rather than cover it up. The teacher’s voice can be propagated throughout the room by shaping a sound reflecting gypsum board ceiling over the front of the room or by making the center of the ceiling a hard, reflecting surface (see figure 1). This will help project the speaker, so they don’t have to strain their voice to be heard over the students.
Reducing Reverberation
Often reducing the dimensions of a classroom to attain a more suitable reverberation time is not feasible, but one can improve the acoustics by introducing sound absorptive materials. Typical classrooms usually have a dropped “acoustical” ceiling that has some absorptive qualities. In classrooms that don’t have this ceiling, reverberation can be reduced by installing an acoustical ceiling or a number of fabric faced fiberglass panels, like Sonora® Ceiling Clouds. Likewise, if there isn’t carpeting in the room, you can marginally reduce the reverberation time by installing sound absorptive flooring.
Wall treatment: Acoustic Panels
If the ceiling and floor are at least rudimentarily treated, then hard walls are usually at fault for poor speech intelligibility. Absorptive wall panels, like Acoustics First Sonora® panels, are a common treatment to control lateral reflections and reverberation.
These panels are popular because they can be customized with a variety of colors, edge designs and fabric facings. They also can come with a high-density fiberglass adder that improves durability. In classrooms, these “Hi-impact” panels are particularly useful because the adder allows for the panels to be used as tack boards. This brings an extra level of functionality to the panels outside of their absorptive properties.
Though wall panels are a perfectly suitable treatment, uncovered areas between the panels can sometimes allow a few hard reflections and/or flutter echo to still occur (although full treatment of the walls would likely result in a room sounding too “dead”). For these situations, Acoustics First often recommends Sound Channels® acoustic wall fabric.
Acoustical Wall Fabric
In many instances, acoustic wall fabric is actually a viable alternative to traditional wall panels. Unlike a typical “wall carpet”, Sound Channels® is made of 100% recycled content and has ridges to increase surface area and absorption. Perhaps most importantly, the uniform coverage you get by treating the walls with acoustic wall fabric eliminates the flutter/slap from reflective parallel walls (without making the space too “dead”). Acoustic wall fabrics are generally light weight and most can be put up just like any other wallcovering.
Also of note are the additional benefits when using Sound Channels® in early education classrooms. The effective range that this wall fabric controls is the higher speech frequencies, which is the ideal range for classrooms with younger children (there are not many bass/baritone kindergarteners). Another advantage is in keeping the treatment clean. Wall panels may suck up sound, but they can also absorb fluids (like the occasional juice box). Sound Channels®, on the other hand, is resistant to moisture, mildew and rot. It is also is non-allergenic, easy to clean, and is highly resilient to common wear.
Acoustical Considerations for Classrooms
Although this knowledge has been around for decades, classrooms across the country continue to be plagued by a lack of acoustical forethought. Perhaps as this information becomes more readily available to architects, contractors, administrators and teachers we will begin to see (and hear) better sounding classrooms. School is challenging enough on students and teachers as it is, let’s not compound their daily obstacles by continuing to overlook classroom acoustics.
(Originally published in Christian School Products Magazine – November, 2015)
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