Flexi diffuser

(1 customer review)

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SKU: 443423 Category:
MPN: 443423
Brand: Perfect Acoustic


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Flexi acoustic diffuser

We can produce custom sizes as well.

We offer a 2-month money back guarantee on all our products!

If you are not satisfied with the purchased product, you can return the product without giving a reason within 60 days of receiving it.

The Flexi Diffuser





dark oak
light oak

Product details:

⦁ Adjustable diffuser lamella and sound absorber – in one
⦁ Eliminates the rattling echoes and the standing waves.
⦁ Allows to set-up the angles of the diffuser lamellas.
⦁ It is ideal for recording studios, hi-fi and media rooms, home theatres.

What is flexi  diffuser?

The flexi acoustic diffuser is an innovative acoustic device that combines the sound diffusion by sound absorption, by simultaneous regulation of high-frequency echo and reflections.
The diffuser-absorber, the size of which is usually 120x60x20cm, has 6 variable diffuser lamellas. By rotating these hardwood lamellas to various angles, they are suitable for diffusion of high and low frequencies which results in a desirable energy spread, corresponding thereby the most to the room.
Behind the lamellas there is a high-density sound absorbing panel of 6 cm thick which absorbs the directed energy efficiently up to 300Hz while it creates resonance among the lamellas.

What material are they made of?

It is surrounded by hard and heavy blockboard for the high capacity.
The built-in sound absorbing panel contains also high-density acoustic wool built in a 2cm thick wooden frame which targets directly the critical low and middle range with its thickness of 5 cm and density of 90kg/m3.

flexi placement

Quick positioning:

It is advisable to position the Flexi diffuser behind the listening position (1-2-3 pieces) the way it covers the width of the workspace.
After fitting them into their place we can experience the increase and clarity of the airiness and spaciousness in the room while they absorb the stronger reflections, standing waves and the rattling echoes.
This is why the production of high-quality sound is particularly applicable in places such as listening rooms, more sophisticated home hi-fi or video rooms and studios where the closest reflection points entangle the sound in an extremely alarming way.

movement of (5)

The Flexi Acoustic Diffuser can increase the sense of spaciousness and airiness also in small rooms by diffusing the sound energy in the room.

Science and operation:

⦁ Too noisy and overdampened rooms
⦁ Diffusing – opening and diffusing high frequency energy
⦁ Absorption – regulating and absorption of sound and resonance
⦁ Combined approach – control of directed frequencies.

The concept behind Flexi  Diffuser offers an affordable way of controlling high frequency energy. The high-end diffusers are extremely expensive up to 1000 EURO therefore they can be found usually only in high-end rooms. By combining a simple diffuser with a sound absorbing panel the Flexi diffuser has excellent performance. In the next page you can see how that can be achieved.

Live end, dead end room designs

The question is very simple: why diffuse energy first of all? Why isn’t it easier to absorb the entire audio spectrum? Well, we should go back to the dark ages of recordings (around 1960) when many studios were treated only with sound absorbing materials thus the rooms became flat and dull. The engineers soon recognised that the listening in artificial environment results in recordings that do not exist in “real world”.

Sometime in the ‘70s a new studio-design concept came into existence which treated the half of the room with absorption panels (dead ends) while the other half is completely untreated (live end). This plan can be called a “dead end with live end” room design. Its intention was to enable the sound engineer to take critical decisions such as special positioning with elimination of the echo, while enabling the sound to show its real energy at the other end of the room. Although the sound became better than it was before but the problems still existed.

In the ‘80s diffusers started spreading and find their places in the studios in order to eliminate rattling echoes and the problems caused by strong primary reflection. This concept has developed throughout the years, where in most of the rooms the extent of sound absorption is higher at the source end of the room while the receptive end remains relatively alive with the help of natural and artificial diffusers.

Core Audio hifi show, acoustic absorber presentation
Diffusion – high frequency energy

There are many different types of diffusers regarding appearance and design and they have many common features: They have some irregular pattern which are designed to reflect the directed sound broken down and to diffuse its energy in the different parts of the room.

Certain diffusers such as the razor blade are formed to break down each frequency evenly through a carefully designed phase trap. These can be hardly loaded and they are very expensive. There are products such as the grid diffuser, which use a grating that randomly allocates the sound arriving in random angles in the room. These can be built easier and they are not so effective but much more affordable.

The lamellas of the Flexi diffuser are standing side by side. It uses lamellas with variable inclination angle which can be rotated in order to divert the sound from the listening position. This increases the sense of spaciousness and airiness in the room. This special design is an extremely great solution as it can optimise the sound scattering and the direction of the reflection according to the seating position.

Sound absorption and diffusion: checking sound energy and resonance

The Flexi acoustic diffuser differs from the other products in that it combines sound diffusion with sound absorption. You can think of it as a two-way loudspeaker where the loudspeaker generates the high and the subwoofer generates the low frequencies. In this case the low frequencies dissipate among the lamellas with variable inclination angle and the low frequencies are absorbed by the absorbing panel behind them.

The built-in sound absorbing panel alone is a specially developed 5cm thick acoustic wool. As it pushes away the low frequencies in the opposite direction to the air gap, the sounds widen with a further half an octave. That means that it will be 80% more efficient below 250 Hz, thus it remains far below the change of direction zone (100 Hz). Any kind of low frequency that gets over the lamellas will be absorbed and any sound that gets into the sound trap behind the lamellas – which may cause resonance – will also cease.

Combined approach: control and diversion of directed frequencies

As we have already mentioned the acoustic experts usually agree that sound waves below 200Hz tends to radiate in spherical shape. In fact, the task of the acoustic diffuser is diffusing energy and absorbing a part of it (specific for the material). As the high frequencies contain less energy than the low ones, they are much more treatable – controllable. Therefore, the treatment of high frequencies above 1000 Hz is not a difficult task. Greater challenge is the case of lower frequencies. The calculation and use of the simple quarter wavelength require a device of 8″ depth for a diffusion of 400 Hz.

It is important to know that without a high-density weight the sound will pass over smoothly. For example, a plastic bag does not contain sound even if it may contain air. Therefore, the Flexi diffuser is made of heavy and high-density wood: when the sound hits the lamellas the most of it will be reflected into the room.

Details and specifications:

The Flexi diffuser is a combined acoustic diffuser and sound absorbing panel which helps to eliminate the standing waves and the rattling echo without overdampening the room.

The innovative design starts with six vanes adjustable to different directions, which can be rotated or positioned such a way that they remove the sound energy from the primary listening position. Behind the lamellas there is high density 5cm thick acoustic wool of 90kg/m3. It provides double use by eliminating the harmful resonance while absorbing the undesired lower frequencies. With this acoustic panel the space expands as it eliminates the long reverberation time provided by the bass thus hearing the high frequencies clearer.

You can easily clean the external wooden frame, it is made of hardwood with 5 different colours. You can buy and transport the Flexi diffuser assembled avoiding thereby the trouble of home assembly.

How to use:

We deliver Flexi  Diffuser assembled in a dedicated box. Most people need around 5 minutes to mount it on the wall. You can easily hang it with the added hooks.

You can place the Flexi diffuser anywhere in the room to dissipate the sound energy efficiently. You do not have to drill it or fix it because its robust size prevents it from falling. You can use it even if it stands on the ground.


The determining factors of the positioning within the room depend on the layout of the room and on the desired sound. The big advantage of the acoustic diffuser is adjustability. This way it can create a duller sound absorbing area from the diffuse (scattered) sound environment or contrary a more vivid sound from a dull sounding area.

The Flexi Acoustic Diffuser is usually equipped with six or more unit of inlet ports (or more for specific size) to protect the width of the listening area or the workspace. You can pile up the panel in a way that they cover a whole wall in order to better control the answer of the room between the sound diffusion and sound absorption.


Application – Rear wall positioning

Acoustic diffusers are usually placed in the rear part of the room where the direct sounds arriving from the monitor loudspeakers may cause problems by creating strong reflections and phase delays. In order to achieve the best result most designer assemble several Flexi  Diffusers which cover the whole workspace behind the listening position. These are usually in the centre of ear level or somewhat higher to maximise the “width” of the auditory space. Therefore, the centre of the c diffusers must always be in ear level if you are sitting.

Flexi the wall


Application – Corner positioning

In smaller rooms the Flexi  Diffuser may add sense of spaciousness and airiness by diffusing sound energy. The lamellas with variable direction allow to remove sound energy from the primary listening position and to use the natural borders of the room by diffusing high frequency energy. The inner acoustic panel also helps to absorb low frequencies – this is a general problem in every small room.

Flexi the corner

Application – Varying acoustics

The optimisation of the acoustics of a room with measuring instruments alone does not always make possible to be ideal for a listener. The acoustic musical instruments such as the violin, cello, acoustic guitar and piano demand a livelier space while the electronic guitars and drums output more energy. Therefore, sometimes different room absorption must be set. The Flexi Acoustic Diffuser makes the change of studio acoustics simple as it simply rotates the wooden lamellas of the acoustic diffuser to the opposite direction compared to the sound reflections.

How do I set the exact direction of the slats?

The simplest way is to sit in the listening position and hear the different reference music’s while your friend rotates the lamellas slowly. You must only set the angles where the sound is less blurred and airier. This usually happens like it diverts the sound from where you are sitting. After choosing the desired position mark the position of the lamellas with a pencil or marker to remember them.

Is there a specific angle which functions the best?

Not really. Although its rotation to the perpendicular position is the worst position as the sound is simply reflected from the hard surface. The use of imaginary vectors or a mirror often helps to determine the ideal positioning in the room.

Is it as good as other products?

Yes and no. Remember that there is no acoustically perfect room, and human brain and ears compensate the anomalies of a room very effectively. After finding the convenient setting you will get to know your room in practice and thus you will know what it produces.

In a studio, can it be hung on the wall?

Yes, of course, why not? We did not design it specifically for such use but its structure holds it easily. It is heavy therefore if you decide to use it that way you must ensure appropriate security.

Can it be used instead of the side acoustic absorber?

Yes, of course. If you have a particularly sophisticated audio room (with many reflections) and you want to add the ancillary treatment the Flexi Acoustic Diffuser would be a great choice as it will keep the room airier while it will absorb the sound from even 40Hz.

I noticed that we rarely talk about the problems of high frequencies. Why?

We can control high frequencies much easier than low frequencies. That is why we usually talk about the high volume of low frequencies in a room. Beside diffusion every acoustic panel handles the control of high frequencies therefore we usually do not mention it.

Can it be used instead of a bass trap?

It depends on what is the problem with the bass. The Flexi diffuser absorbs the bass efficiently from 40Hz but it will not be as efficient as a bass trap. If we experience a too big reverberation we should combine it with the corner units or our bass traphttps://perfect-acoustic.com/termek/cube-bass-trap/

Can I mount the on the wall in a way that there is a small gap between the wall and the diffuser?

Yes. There are no exact rules in acoustics. Generally speaking, the closer it is to the surface of the wall the less low frequencies it will be able to absorb. As it moves further from the wall it will be able to absorb more low frequencies while the sound diffusion increases. Thus, it operates as a magnifying glass.

Where to put it in a home theater?

The best place would be probably in the “reflection point” or on the walls where the strong direct sounds are the most noticeable. So, if you have a loudspeaker which is close to a certain wall and the wall causes reflection you should use the Flexi diffuser there.

What is natural diffuser?

There may be many kinds of natural diffusers such as bookshelves or rooms with odd lengths and widths. They are in fact hard surfaces that may turn over and diffuse the sound energy that is hitting them.

Is it a good idea to place the absorbers among the diffusers?

Yes, why not? Remember that there are no rules cast in stone in acoustic treatment. If we create a relatively neutral working environment which allows to enjoy our records in other rooms as well. Some people enjoy the record in a relatively untreated room while others prefer the sounding of a duller and calmer or a more intensively treated room. The perfect setting of a room usually requires several months’ work and you will hear only thereafter how it will function. This is normal for every room but after that the most engineers like to work always in the same room.

hifi room acoustics repair

Our diffusers are made of real wood, due to the natural properties and structure of the wood material (knots, lumps, staining due to leaking resin), the pickling / painting will not be even, the shades may be different on the entire surface of the diffuser, therefore we cannot complain to accept.
(The beauty and style of natural wood lies in the fact that due to the veining and the structure, special colors and shades can be achieved during painting / pickling.)

Additional information

Weight 20 kg

104x60x18cm, 120x60x18cm


black, dark oak, light oak, white

1 review for Flexi diffuser

  1. goliatxd

    Hello! High quality panels, handmade. Fast delivery, good raw materials. I’ll order in the future! Thank you Perfect Acoustic

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