Where to place qrd diffuser panels

QRD diffuser


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Non-EU countries that can be purchased without VAT: United Kingdom, Norway, Switzerland, San Marino, Liechtenstein

QRD diffuser

  1. Size: 120x60x10cm Weight: 15kg
  2. Size: 104x60x10cm Weight: 15kg

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

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

QRD diffuser properties

  • Striped acoustic diffuser features diffusers made of pine wood or laminated furniture board
  • It sucks the low frequencies and dissipates the other frequencies in a high bandwidth.
  • Most studios order this diffuser
  • Where perfect sound is most important.

5 different color:

acoustic diffuser colors

  • natural, real fir wood 104x64x10cm, 120x64x10cm in size
  • dark oak, laminated oak board only 104x64x10cm in size
  • light oak, laminated oak board only 104x64x10cm in size
  • white, laminated board only 104x64x10cm in size
  • black, laminated plate only 104x64x10cm in size

Foldable wooden legs are also available on request


You can wipe this with a damp cloth.

The science is behind the sound diffusers

The sound diffuser is an object that disperses the directed sound waves and is intended to reduce the primary reflections, the standing waves and the rattle echo. It is an excellent addition to a sound absorption panel as it does not return the sound energy like a normal acoustic panel.

Diffuser reflects the energy into the room. In contrast to the flat and straight reflective surfaces, which reflect energy, the diffuser diffuses the sound thanks to the different depths in different directions and at different times.

This eliminates direct mirror reflection and gives the impression that it is a wider and larger environment.

Although people have used sound diffusion since Roman times, in recent years modern mathematics has come up with new designs that can be used to calculate measurable results.

The doctor M Schroeder - the driving spirit of the first-order diffusers - created a series of mathematically calculated boreholes with different depths. These have been set to distribute the same volume of energy based on pre-calculated dimensions.


The sound arrives as a wave front and enters the phase grid of the diffuser, where it is reflected into the room. As the depth of the depressions varies, the energy exits at different relative times. This shifts the relative phase or time difference (time shift) and distributes the energy among the wells, creating spatial diffusion.

Diffuser-free sound reflection directly from the wall.

The sound arrives as a wave front (blue). Without diffusion, the flat and hard surface of the wall reflects the energy (red) like a mirror, which causes an echo. These can even be reflections of the first waves that we hear in the form of a rattle echo.

The wavefront enters - the energy hits the shallow pits first and is reflected back into space, while the remaining part flows into the deeper pits. The “time shift” happens over time when these waves enter the diffuser, which are reflected and then left again.

When identical frequencies enter and exit the same pits at the same time, they are in phase and mutually reinforcing. If they emerge at different times, the phase drop occurs depending on the frequency and depth of the pit.

As soon as the sound waves emerge from the various depressions, they interact with each other and the energy is diffused through the phase grating, which leads to a horizontal "spatial shift". As a result, the sound is diverted in the room and the feeling of space is strengthened.

Setting the low frequency power

Sound consists of different compressions of air molecules, which are called sound waves and whose length depends on the frequency. Lower frequencies have a longer wavelength than the higher ones.

With the same amplitude, these contain more energy than the shorter high-frequency sound wavelengths, which make regulation even more difficult. In addition, it is generally believed that the sound begins to straighten above the 300 Hz range.

If the main function of a diffuser is to dissipate the directed sound energy, the optimal sound diffuser must reach into this lower frequency range. These criteria determine the low frequency performance target for the diffuser.

When planning the diffuser, the density of the material for the deepest depressions and the specific gravity should be the lowest frequency with which it can diffuse.

Room acoustics design

It is also important that the diffuser be structurally stiff and heavy enough to avoid the bass creating unexpected resonances and that it be heavy so that the energy does not just flow through the depressions.

This is more related to the sound diffusion effect of the diffuser, which does not stop at a certain frequency, but rather decreases with decreasing frequency. This means that the QRD diffuser works smoothly from 150 Hz.

Since most people are of the opinion that the sound can also be reproduced below this frequency range (actually not from 150 Hz), it is advisable to also take the lower frequencies into account.

High frequency tones

Clap in an empty room for fun and you will likely hear a range of echoes depending on bouncing and bouncing off the wall, ceiling, and floor.

We call this rattling echo, which is very strong in rectangular rooms with hard surfaces. What you hear are the high frequency sound waves bouncing off these surfaces. The high frequencies are more directional compared to the low frequencies, which is why they act as a bouncing ball.

Compared to bass, these quickly lose their energy at the same amplitude if they get through any medium such as air, liquid or solids.

How can I use the QRD diffuser?

The diffuser is a high-performance diffuser for professional studios and more demanding home theaters and hi-fi rooms.

The QRD erie is optimized so that several diffusers can be mounted next to each other. This enables the customer to set the desired number of diffusers in one place that cover the desired wall.

Once these are installed in place, problems such as modal distortion, clatter echo, and standing waves are greatly reduced.

The diffuser has to be heavy and stiff to work well at a lower frequency. Of course, this leads to questions such as positioning or assembly. The good news is that we designed the sound diffuser so that it can be fitted easily and quickly.

You have to assemble these using the same technique as with kitchen cabinets. If you are wall mounting you need to place it at ear level so that the center of the sound diffuser is at ear level. Of course, you do not necessarily have to mount these diffusers on the wall, as they are stable on the floor and fully do their job.

QRD diffuser positioning

The best position in a room is usually behind the listening position or behind the speakers on the right or left. Of course, a larger room offers a larger diffuse area. In rooms with a larger work area, it is advisable to combine these with membranes or broadband acoustic panels in order to save money.

Reflection point behind the student position

Wide wall surfaces

In rooms where the wall behind the listening position is very wide, you can cut costs by adding a broadband acoustic panel to absorb the bass. This is particularly important in order to improve the acoustics and to achieve an even sound in the listening position.

If you want the same size as the diffuser, you can also order acoustic panels in special sizes. Custom-made products do not increase the price. This makes the alignment easy and attractive. The best solution is that you put the QRD diffusers inside each other as this will result in a balanced diffusion.

Reflection point behind the student position

Built into the wall

Are you building a control room, home theater, or studio? You can mount the QRD diffuser just as easily as mounting a shelf. Recessed mounting does not affect diffusion performance, but it can improve the aesthetics of the room when you are ready to build.

When the studio is already ready, you can build a partition to mount the diffusers. It can be a great opportunity to provide acoustic isolation between rooms or to install a large built-in bass trap.

acoustic diffusers placed in a wall

The audiophiles are probably the most demanding of listeners. By adding QRD diffusers, the annoying reflections in such listening rooms can increase the airiness.

This is especially important when listening to jazz or classical music that has been recorded in an acoustically extensive area, as the advantage of these recordings is the natural acoustic environment.


Do all diffusers work the same way?

No. Due to the way the diffusers work, the sound energy is reflected and distributed in the room. The massive, high density diffusers can control the low frequencies while the thin and light diffusers can only control the higher frequencies. The size, weight and design of the diffuser play a very important role in its operation.

Why do certain companies state that plastic or styrofoam or foam diffusers are also effective at lower frequencies?

Because of the profit, of course. For them, the regular customer is not important, but that they disappoint the customer once or twice. Since these are usually cheaper (not always), everyone starts with them and only when they realize that they are ineffective do our premium quality products arrive. Unfortunately, your wallet will be considerably smaller by then.

Why are the QRD diffusers so expensive?

The problem with the real diffusers is that there is no easy way to produce it, it's not like a simple bookcase. The diffusers are mainly handmade, hand glued, hand assembled and hand packed which takes a lot of time. That's why it's so expensive.

Can I make my own QRD diffuser myself?

YES. However, it is not certain that it will be efficient. If this is calculated and measured incorrectly, it will be incorrect rather than beneficial.

Where is the best place in the room to mount the diffuser?

Especially in the primary reflection points, behind the loudspeakers at the right or left mirror point or behind the listening position.

Can I repaint the QRD diffuser?

Yes of course, but we sell it in 4 different colors besides natural colors that you can see in the photos.

acoustic diffuser colors

Additional information

Weight17 kg

black, dark oak, light oak, natural, white


104x60x10cm, 120x60x10cm