What is the role of an acoustic diffuser?

We already discussed a great deal about the treatment of the bass and the dampening of the echo. Indeed, these are the most frequent acoustic issues however we will fail to achieve the perfect sound if we concentrate solely to
these problems.

Diffusers also have a great importance in the acoustic treatment, certain
issues can be solved only with the application of them.

The two most common acoustic issue for which our customers turn to us

Most of the requests we get originate from the following situation: the client purchased the long-sought and carefully selected Hi-Fi or home
theatre equipment but even after adjusting all possible parameters of it, he or she still have not managed to achieve the desired sound.

But when he or she listened to the equipment where it was purchased it produced a sound of his or her dreams. Usually the problem that lies behind is originated from one of the two cases explained below.

Acoustic Absorber in Barabas villa

Sound absorption

Over dampening of the high frequencies, lack of  sound diffusers.

In one case the importance of acoustics was not unknown for our client, he started the acoustic treatment with homemade units based on information found on the internet or recommendations of friends.

The treatment means the most frequent practice i.e. purchasing acoustic foams or diffusers made of styrofoam which are glued to the wall.
Perhaps he uses inappropriate and unmeasured absorbing materials e.g.
fibreglass or mineral wool. He turns to us sincethe acoustic anomalies persist even after the home-made treatment.

One should be aware that due to their density acoustic foam and the styrofoam are inappropriate to absorb or scatter low frequencies. However, they can mitigate high frequencies therefore they seem to be effective for the first time as they reduce the reflections of high frequencies.

Despite of this later on customer realizes that the result is contrary to his or her original intention and concept:

  • increased strengthening of bass,
  • distorted bass,
  • echo,we don’t hear the real amount and quality of low frequencies but the sound of the room.

Dampen the echo!

At this point we arrived to the other most common problem. Despite of the well installed equipment we hear strong echo that spoils the pleasure of watching movies or listening to music.

At this stage some people already turn to us asking for a help in the acoustic treatment, but many of them rather try to find some home-made solution, and purchase some absorbers. Following this people turn to us for the below mentioned reasons.

The mitigation or scattering of the bass will be unsuccessful if the density of the absorber/diffuser is inappropriate or it is made of unmeasured, untested material, or it is placed in a wrong location.

However, if the home-made solution is “over successful” i.e. the absorber absorbs the sound waves but certain frequencies can be over dampened which again makes the listening to music or watching movies unpleasant.

The above-mentioned cases show that sounds not only need to be absorbed but also to be scattered. In order to get a clear, dynamic sound without echo we also need sound diffusers.

flexi diffusers placement.

Sound absorption

Professional acoustic measurement and design instead of home-made solutions.

Instead of home-made solutions we can spare time and money if we entrust a professional with the treatment of acoustic issues. In the
course of the acoustic measurement depending on the parameters of the room we can specify which type and how many panels do we need and where we should place them in order to achieve the desired sound.

How do  sound diffusion work?

You have certainly encountered the phenomenon that after furnishing an empty room the echo decreases gradually in parallel with the furnishing of the room.

The reason of that is that furniture fittings do act as diffusers. In case of acoustic diffusers, we can calculate their diffusive impact before their
implementation therefore it can be planned.

Acoustic panels have irregular shapes thus they can divert the sound waves reaching them – they reflect the waves in a different angle than the wall does – and can scatter them within the room. One can observe that diffusers are constituted of units with different depth.

Despite of its irregularity the surface of diffusers is well designed: they
reflect different frequencies in different directions.

The denser the material they are made of the lower the frequency they can divert.

Diffusers filter frequency spikes, they cancel out the rattling echos originating from the reverberation of high frequencies. Based on acoustic measurement, placing them at the appropriate location we will experience the following when using them:

  • direct echos are reduced,
  • Improvement in details and vocal clarity,
  • pleasant, natural sound can be achieved,
  • spaciousness increases, without creating an anechoic chamber.

2 in 1: what can an sound-proof with
diffuser offer?

Within our product range, besides  diffusers, we can offer acoustic panels with diffuser. These are acoustic units to which a diffusing face plate is installed and thereby it can absorb certain part of the frequency range
while it can reflect some other frequencies at the same time.

It means that it has a reflecting, scattering impact similar to  diffusers.

Compared to broadband absorbers, it absorbs more low frequency – below 300Hz – but less high frequency – above 600Hz. In that way it ensures that high frequencies won’t be overdamped in the room.

Perfect Acoustic – comprehensive acoustic solutions with Sound diffusion.

Judging the sound quality is indeed a subjective issue. Some people like the sharp highs, others prefer bass tone or buzzing bass.

Whatever group we belong to we can be sure of one thing: if we concentrate exclusively on audio equipment and cables in order to achieve the ideal sound experience, we will be disappointed.

In such cases the solution is not to purchase new equipment constantly which are believed to be better and to have higher quality. We can reach our goal by eliminating the distortions existing in the room. Acoustic measurement, treatment and acoustic items produced by us can help you to achieve that 

It is true that ceilings, walls, windows…, etc. also function as sound-reflecting surfaces, but due to their flat, hard surface, all sound energy is reflected back in the same direction, concentrated, so the sound will be echoing, unpleasant. Acoustic diffusers, thanks to their irregular surface of different depths, radiate the energy of the sound into smaller parts, distributing the sounds more evenly, thus creating a more balanced, more spacious acoustics.

It is important what material we use:

The material of diffuse surfaces is not a negligible aspect either. Hardwood, which has excellent absorption, is generally used as the raw material for sound-absorbing and diffuse elements. Acoustic cotton, acoustic silk, or imitation leather also have effective sound-absorbing and scattering properties. For acoustic purposes, high-density but flexible and fibrous materials are suitable. Therefore, cellular styrofoam elements or egg boxes are not suitable for acoustic treatment, the latter are only good for dust catchers… The higher the body density of a material, the better its sound absorption capacity.
It is not necessary to cover the entire wall or ceiling surfaces, the primary reflection points must be covered with diffusers. These points can be determined by acoustic measurement.
The diffusers can also be placed on a wall or ceiling, or even on the floor. (with folding legs)
You can order several colors, patterns, sizes or designs. Thus, not only do our diffusers perform to the maximum in the acoustic field, their aesthetic design allows them to be decorative decorations for any style of room.

 

Written by Róbert Polgár

Categories: Tutorial