Acoustic treatment : restaurant, classroom, open space, offices, hi-fi and cinema

Introduction

We will therefore see, in this article, the difference between acoustic treatment and sound insulation. We will understand the ins and outs: their different materials and respective objectives.

We will then talk about the different products that exist to improve acoustics, namely: acoustic panels, diffusers and bass absorbers. We will see their advantages, how to choose and position them, and under what conditions they can be used.

We will then discuss the interest of measuring your room acoustically: when is it necessary, what is the benefit, …

After that, we will tell you how to optimize your part before processing it.

Finally, we will talk about the advantages of our solutions: their aesthetics, acoustic properties and much more.

The basics of acoustic treatment

The difference between acoustic treatment and sound insulation

People often tend to confuse acoustic treatment with sound insulation. We will agree that these notions are close: they aim at optimizing noise management, very often by reducing it. However, they differ on one major point:

1. Acoustic treatment seeks to optimize the sound within a room,
2. Whereas soundproofing (or acoustic insulation) seeks to prevent noise from outside a room from propagating into it.

To make it simple and more concrete, sound insulation will serve to prevent the noise of the train near you from “entering” your living space (house, apartment, castle, …). The acoustic treatment will not be of any use in this case. Indeed, it seeks to “break” the echoes that you have in your room. Thus, if your room resonates, the acoustic treatment will be adapted to your situation.

What to choose according to your needs?

The usefulness of sound insulation

Cases where sound insulation is suitable :

1. A train passes by your home and creates a noise nuisance in your home.
2. Your neighbor is often partying and you are bothered by his noises.
3. You can hear the noise from the living room into your bedroom.

The usefulness of acoustic treatment

Cases where the acoustic treatment is adapted :

1. You wish to obtain the quintessence of your musical listening: in a dedicated or non-dedicated room
2. You want to optimize your musical practice: whether you are a recording studio or a musician
3. You are planning to build a home theater
4. You have echo or resonance problems at home
5. The room you wish to treat has a permanent hubbub: it is thus difficult to listen to each other talk. In this case, take the image of a restaurant where you are used to having lunch. Then ask yourself these 2 questions:
   1. Do you have difficulty communicating with the person in front of you?
   2. Does the noise bother you?

A simple test consists of clapping your hands to see if the sound “bounces” and comes back to your ear several times. If it does, there is a strong echo in the room you are in. This is also called an acoustic reflection. Acoustic treatment will therefore greatly improve your sound environment. Indeed, in this case, you need absorption.

The problem with this sound discomfort is that there is a reverberation of sound on the walls of the room. The solution? Reduce the RT 60 to prevent this reverberation.

A bit of technique

In order to better understand acoustic treatment, we can thus take an interest in the different noises perceived by human hearing.

There are thus 2 types of sound waves that can be identified by the human ear:

1. The direct sound wave: which corresponds to the sound that will propagate from a source directly to the human ear.
   • Example: when someone talks to another person, part of the sound is not “bounced” off the walls of the room, it is this sound that is called a direct sound wave.
2. Indirect sound waves: which correspond to the sound that will reach the ear indirectly, i.e., after “bouncing” off the walls, ceiling or floor of a room. It is these waves that induce a sensation of unpleasant noise or distortion.

Who is concerned? Acoustic treatment for restaurants, classrooms, open spaces, offices, hi-fi, …

As mentioned, the acoustic treatment will concern any professional or individual who wants to solve resonance problems in a room. We have created different tutorials to better understand the interest of acoustic treatment according to your situation. To learn more, please read them:

• Acoustic treatment for restaurants
• Acoustic treatment for offices and open space
• Acoustic treatment for schools

What needs to be done to improve acoustics?

Depending on the size of the part and the materials it contains, the treatment recommendations will be very different. Depending on your objective as well. For example, a dedicated hi-fi room and a living room are not treated in the same way.

Regarding the acoustic treatment, we will therefore play on the elements seen previously (curtain, acoustic panel, furniture, …). It should be noted that the slightest change can be fruitful or, on the contrary, disastrous. Calling on a professional is a guarantee of reliability.

Acoustic sound diffuser or absorber?

Acoustic treatment improves many things in one’s life: listening comfort (for the music, but also during conversations, …), and consequently, quality of life.

However, it makes little sense to treat your room too much. Indeed, it could end up sounding like “dead”.

It is thus advisable, first of all, to be interested in absorption, in order to remove the defects of the piece, and to manage the reverberations. Then, in a second time, to add diffusers in complement to improve the naturalness and the dynamics of a room.

To return to the technique, the interest of the acoustic diffusers (in photo) is to disperse the acoustics reflections to prevent them from being trapped, and thus keep the sound “natural”.

Products to improve its acoustic treatment

1. Acoustic panels – to absorb mid to high frequency sounds. This is the essential element to process your acoustics and get the best out of them.
2. Diffusers – to disperse and fragment sounds. Its role is not to absorb energy but to redistribute it intelligently in order to make a room more alive and musical.
3. Bass absorbers or bass trap – in order to contain the low frequencies. They bring a considerable plus, essentially to take full advantage of its Hifi or Home cinema system, its practice or its musical recording.

Very often, the brands present on the market are mainly interested in the acoustic properties of their solutions. At PYT Audio, we believe that acoustics should blend in with your decoration. Therefore, we have developed products that are easy to integrate, which we will discuss in the next section.

Acoustic panels

We offer several ranges of acoustic panels to solve your various problems related to sound absorption. We have therefore opted for four main ranges:

1. Access: having an interesting price, it is adapted for large surfaces. It can be re-cut, but it has a “standard” efficiency and a choice of only 4 colors.
2. Reference: it integrates a vibration absorption technology thanks to a honeycomb vibration transmission plate. It is also very well finished and still modular.
3. Exclusive reference: it is based on a reference frame, but has a more qualitative range of fabrics with a wide choice of colors!
4. MUTUM: this range is suitable for professionals and individuals. It is made of products with 100% recycled and recyclable materials.

Custom-made acoustic panels are also possible (if our range of fabrics does not suit you, for example). We can also make printed acoustic panels. You want, for example, to reproduce a painting on an acoustic panel, it’s possible!

Where and how to position your acoustic panels?

In order to obtain better performance or a more important feeling with acoustic panels, there are different positioning “strategies” depending on the objectives you have.

Here, we will distinguish between the treatment of a living room, a Hifi room, a Cinema room or a Home studio.

If we want to treat a living room, we will not work in a symmetrical way, we will avoid that the panels are facing each other.
And we will try to work on 2 adjacent walls: one wall in length and the other in width. If there is a high ceiling height, the ceiling will be treated first.

We proceed this way to avoid the sound from spinning in the room and reverberating on the parallel walls, but also because the noise emission points are not fixed. Indeed, people move in space.

To better understand the process, we have made a more complete tutorial on the acoustic treatment of a living room.

In a hi-fi room, it’s different because the point of noise emission is fixed.

We will first put panels behind the speakers because the sound “leans” on the wall behind the speakers. In fact, each change can be heard instantly.

Depending on the desired result and the budget, we’ll put either diffusers or absorbers. Then, we will try to work on the primary and secondary reflection points. We will treat in the most symmetrical way possible in order to respect the stereo effects, which will allow us to optimize the sound image.

A more precise tutorial also exists to better understand the acoustic treatment of a hi-fi room.

In a Home Studio, we often have only 2 speakers. However, we will favour a Home Cinema type acoustic treatment because the objective is to have little reverberation. Indeed, microphones are very sensitive to reverberation and this will be felt instantly on your sound recordings.

If the objective is to have a very fast, dry, and natural sound, we will favor diffusing panels rather than absorbing. But always in complement of an important treated surface.

A complete tutorial on the acoustic treatment of a home studio exists on our site.

How many acoustic panels to choose?

The quantity of panels to choose will, again, depend on your objectives.

In any case, to obtain the result you want, you can work empirically, gradually adding acoustic panels to the wall or ceiling.

The safest way is to contact us and explain us :

• Your project
• The size (in m²) of the part to be treated
• The different materials present in the room
• The possible sound problems
• And, if possible, some pictures of your room

In a living room

For a living room, count 1 panel per 2 m² (floor area) at least for an audible result.

With 1 panel per m² the result will be more significant in most cases.

For rooms with large surfaces (70 m ² and more) or with large volumes (ceiling height over 2.70 meters), count a minimum of 1 wall panel per m². You should also consider treating the ceiling with larger panels. In this case, it is best to contact us.

It is ideal of place “blocks” of panels from 1 meter up to 1 meter 80 (ear height). If possible (depending on the objective and the budget) they should be placed practically up to the ceiling (at 2 meters 20 / 2 meters 40) to improve the result.

For a hi-fi room, at first, we are not looking for a reduction of the reverberation time but a control of the energy in order to obtain a better sound quality. To do this, we will treat the wall behind the speakers.

When we are going to treat the primary reflections :

1. If the room is small (10 to 20m²), we are close to these reflections, and so are the speakers. So, with 4 to 6 panels, we will easily manage to treat a sufficient surface to remove the distortions linked to these waves.
2. If the room is larger (20 – 40m²), one is generally further away from the reflections, and so are the speakers. Thus, the wave will be more “dispersed” and it will be preferable to treat a larger surface. This both to suppress reflection and to reduce the reverberation time of the room. 6 to 9 panels will generally be more appropriate.

In absolute terms, treating the reflection at ear level (i.e. panels placed between 1 meter and 1 meter 80) is sufficient. But if you wish to optimize the result, do not hesitate to place a row of panels up to a height of 2 meter 20 – 2 meter 40.

In a movie or music room

For the studio and home theater, depending on the budget we will work:

1. Either as for a living room: for the Home studio in order to have a natural reverberation low enough.
2. Either as for hi-fi: in the case of Home Cinema, but with the necessary variations in placement.

However, in order to reduce the reverberation time sufficiently, the number of panels will be increased accordingly.

Is thin acoustic panels a problem?

You want discreet and aesthetic acoustic panels but you are afraid of their efficiency? Indeed, you have read on a forum that low thickness rhymes with a ridiculous absorption coefficient.

This may be true for some products on the market that use porous materials as their only working principle.

However, at PYT audio the panels are designed on a multi-layer and multi-density technology to become true “vibrating blades”. This in order to increase the absorption coefficient. Moreover, from the reference range, a honeycomb plate is integrated and allows an extended and optimized absorption capacity.

In addition, our acoustic products have been validated by many independent professionals from different backgrounds:

1. From the world of hi-fi: 6Moons, Audiophile magazine, Mono&Stereo, Vumeter, …
2. From the world of music : MusicTech
3. From the world of decoration: “Maison & Jardin”

Our customers are also very satisfied!

Press notice

Acoustic sound diffusers

The diffusers will come, very often, in complement of the acoustic panels or the bass trap. They seek, indeed, to disperse the waves that have not been absorbed by the two previous acoustic correction systems. In other words, after having corrected the major defects of the room in terms of reverberation, the diffusers will try to reproduce the sound in a natural way. Thus, they try to reproduce the sound in an energetic way, without the absorption stifling it too much.

Our solutions :

1. Exclusive low profile diffusers: a compromise between absorption and diffusion. This diffuser keeps an absorption capacity on certain frequencies while trying to “give life” to the sound. It works on the principle of the Schroeder diffuser, but in an “inverted” way.
2. Exclusive polycylindrical diffusers: it works on the basis of the poly-cylinder. It only seeks to diffuse the sound in an authentic way, without absorbing it.

Our poly-cylindrical diffusers have 3 major advantages:

• They contain a concave resonance suppressor.
• They integrate a Helmholtz resonator.
• They allow a mechanical improvement of the inertia.

This means that they remove the flaws inherent in the basic mathematical model, reinforcing the physico-acoustic principles. As a result, this allows our product to be really efficient, not only from a “measuring” point of view but also from a “listening” point of view.

How to position your acoustic diffusers?

The position of the diffusers is similar to that of the acoustic panels.

However, there is one notable difference. The diffusers should ALWAYS be positioned vertically for the poly-cylindrical and low profile (eyelet upwards) diffusers as shown in the picture.

If you don’t respect this principle, the listening result will be less good.

The different types of bass trap

Many forms of bass trap exist. The shape does not play on its efficiency, it is the process and the materials used that will influence the absorption capacity of the bass trap. No classification is official, but we decided to group them according to the following methods:

1. Traditional bass traps: they are not designed to be very “selective” in the frequencies they seek to absorb. Their mode of operation is based on the density and volume of the materials they are made of. The advantage is their versatility and simplicity of use. Our bass trap reference is designed on this principle, but as always, we tried to give it a more aesthetic aspect (large choice of colors and stitching), despite its relatively large dimensions.
2. Specific bass traps: they seek to correct a particular frequency generally determined by a measurement. They operate on spring / mass / spring systems. That is to say with a wooden board that will act as a vibrating blade by being tuned to desired frequencies. This makes it possible to absorb a more limited frequency band, by returning the high and medium frequencies.

Specific bass traps are ideal for studios, dedicated rooms, or for large redundancy problems in the bass. However, they require the services of an acoustician, as well as a custom-made construction. In addition, the volume is usually even higher, and the bass trap will be calculated to work at a specific location in the room.

How to choose your bass traps?

Depending on the materials

At PYT Audio, we have chosen to use a large volume, hollowed-out foam with a “hard” fabric in order to achieve targeted absorption results in the low and extreme low frequencies (from 50hz – 150hz), while minimizing the absorption of the mid and high frequencies.

Indeed, it is the acoustic panels that will take over for these mid and high frequencies.

Depending on the shape

If you want a neat aesthetic, the shape will obviously be of major importance. The color of your bass trap too.

At PYT Audio, we have therefore decided to opt for a bass trap with a wide choice of fabric colors and stitching.

Apart from these aesthetic and visual aspects, the shape will not really impact the absorption capacity. It is essentially the material and the technology that will play on this latter.

How to position your bass traps?

To maximize their efficiency, positioning the bass traps in the corner of the room is practical and improves the efficiency of the system. Ideally, they should be positioned in every corner of the room over the entire height. Our bass traps are 1 meter high, so they should be stacked from the floor to the ceiling. The goal is to treat the room in its full height.

If you’re an audiophile, they should be placed behind the speakers first.

Of course, as we have seen above, these products have the advantage of being easily movable. You can therefore carry out different tests, and make progressive purchases in order to make empirical tests. This will allow you to get the best compromise and perfect balance. Indeed, the acoustic recommendations drawn from curve analysis are not always in phase with our listening experience!

Is it necessary to measure the room?

The interest of measuring a room for acoustic treatment

At PYT audio, we have done everything possible to make life easier for the user and to avoid taking measurements in rooms smaller than 100m².

In fact, a solid experience and the respect of acoustic and physical fundamentals allow a professional result without taking measurements.

It is obvious that a measurement of the room will bring you precision on the absorbed frequencies and will thus allow you to understand the sound changes brought to your room with more precision.

However, this is far from being necessary in all cases. This is especially true if your room is less than 100m². PYT Audio solutions bring you a clearly audible acoustic improvement. You won’t need to take measurements to realize it!

This allows you to make substantial savings if you call on us. You will not need to go through a third party company to make measurements and recommendations. Please note that the services of an acoustician are included in a range of 1500 to 3000€ per room studied. This is because the bulk of the work is not the measurement but all the work afterwards: reading the measurements, modeling your room and furniture in 3D, export to specific acoustic software, analysis of results and various calculations, …

If you would like to find out more about the acoustics of your room at a low cost, you can however carry out measurements yourself by equipping yourself with:

1. A microphone: of a certain quality and therefore a certain price however
2. A measurement software: which can be free of charge as it is the case with the REW software (for Room EQ Wizard).

If you have acoustic measurements, please do not hesitate to send them to us. This allows us to be even more relevant on our advice. However, this is not essential.

The stakes of measuring a room for acoustic treatment

Again, it all depends on your utility of an acoustic treatment. If you only want to treat echo problems, it won’t really matter.

If you want to treat a dedicated room or a home studio, the measurement is more important.

The big strength of PYT Audio? You can move the panels, since they are positioned with a velcro, to adapt your sound ambience according to your current objectives. You can even take them wherever you want! This is ideal if you have to move or if your music studio is not fixed.

What should you do before processing your room?

For individuals who wish to improve the acoustics of an existing room

Start to put carpets, curtains, use high furniture, …

Sometimes it’s enough.

If it isn’t, use acoustic panels as a complement.

For a dedicated room

If you want a dedicated room, you can already start by designing a room with non-parallel walls and a sloping ceiling.

Also consider choosing dimensions that respect the “golden ratio”. But most importantly, dimensions that fit the size of your speakers! So for a small room, choose small speakers.

Most importantly, please respect the law of mass! We therefore recommend that you use as many inert materials as possible that do not vibrate and that are, if possible, natural because the sound of the materials can be heard!

Choose stone, solid red brick, wood, sand, or fermacell instead.

On the contrary, avoid plasterboard, aluminum rails, tiles, metal and glass (or bay windows).

To be able to treat as efficiently as possible, choose a closed room that is up to 35m². Indeed, beyond this surface area, the real difficulties begin: it is often more difficult to make a large room “sing” or make it musical.

The PYT Audio solution: the best compromise between aesthetics and acoustics

At PYT Audio, we understand that the lack of aesthetics of an acoustic treatment can be a real obstacle for you. We have therefore decided to focus on fine and discreet solutions. Our products are 0.9 to 1.7cm thick, while having very good absorption capacities. We offer more than 49 colors to make sure that you will find a solution adapted to your needs!

Also, our products can be moved at will. So you can take them with you when you move house. Our velcro fixations are also respectful of your walls. So, no unpleasant surprises if you wish to move them and present them to friends or others.

PYT Audio, it is also a unique commercial follow-up. Many specialized magazines in the Hifi, music and decoration sectors have recognized our expertise, the quality and uniqueness of our products.

Conclusion on acoustic treatment

We have therefore seen that acoustic treatment should not be confused with sound insulation. Acoustic treatment is concerned with the sound emitted inside a room and concerns elements within your room. Conversely, sound insulation is concerned with stopping the sound coming from outside a room and therefore concerns building materials.

The noise present in your room comes from direct and indirect waves. The latter are the waves that “bounce” off the wall before reaching your ears.

There are 3 main types of products to improve your acoustics. The bass traps that block the low frequencies. The acoustic panels that tackle the mid and high frequencies. The diffusers that mainly allow you to return energy. Depending on your objective and your room, you will choose one or all of these products.

Acoustic panels can be positioned on the walls or ceiling. Very often, treating only part of the walls is sufficient. Depending on the objective, the positioning and the number of panels to be used will be different.

After absorbing certain frequencies, the diffusers try to give “life” to the sound so that the room does not sound totally “dead”. In all cases, they are positioned vertically, i.e. with the eyelets facing upwards.

The shape of the bass trap does not matter and they are positioned in the corners of the room (or behind the speakers), ideally over the entire height of the room, so they should be stacked, as far as possible, up to the ceiling.

Measuring the room is far from essential, unless you’re a professional who wants to achieve a very precise result.

In addition, to optimize your acoustics, choose rooms with different lengths, widths and heights. Also, choose inert materials that do not vibrate and are natural.

Finally, in addition to having good absorption coefficients, our solutions are aesthetic and easily integrated.