FAQ
Frequently asked questions.
Where can I purchase Adelsklang products?
Our products are available at:
• selected musical instrument and pro audio dealers
• selected HiFi and home cinema dealers
oder nutzen Sie unsere telefonische Bestellhotline unter +49 2226 9094808 als auch per E-Mail: verkauf@adelsklang.com
Acoustic Diffuser with 49 chambers vs. 36 chambers or QRD design vs. modified QRD design
QRD design / QR-49 PRO with 49 chambers:
The Adelsklang QR-49 PRO is a real QRD diffuser. QRD diffusers are physically precisely calculated diffusers and offer perfect diffusion performance. Diffusion is absolutely controlled and follows precisely defined rules. QRD diffusers are also known as Schroeder diffusers after the physicist and inventor Manfred Schroeder. The number of chambers in a row in QRD diffusers is based on prime numbers (5, 7, 11 etc.), so the prime number 7 results in 7 x 7 chambers, i.e. a total number of 49 chambers. The ratios of the individual chamber depths correspond to a precisely specified so-called quadratic-residue-sequence. The chamber depths are the basis for the lower frequency range (the deeper the deepest chamber, the lower the lower cut-off frequency) and the chamber sizes are significant for the upper frequency range (the smaller the chambers, the higher the upper cut-off frequency). It therefore makes a difference whether a diffuser with 49 chambers has an external dimension of 50 x 50 cm or 60 x 60 cm with the same overall depth, as the chamber sizes also increase with a larger external dimension and the upper effective range is therefore immediately drastically reduced. This is also the reason why our QR-49 PRO diffusors with their 49 chambers have an external dimension of 50 x 50 x 11 cm. Optimum lower cut-off frequency, optimum upper cut-off frequency and therefore perfect diffusion performance over an enormously wide frequency/effective range.
Modifiziertes QRD-Design / QR-36 ECO mit 36 Kammern:
A modified QRD design is usually used for cost or weight reasons. In this case, a specified QRD design is changed or the number of chambers is reduced. The significant disadvantages of this modification compared to a real QRD design must be accepted. Since the specified rules of the physicist Manfred Schroeder are no longer followed, uncontrolled diffusion and a lower diffusion performance must be taken into account in the application. The usually limited frequency/effective range is a further disadvantage compared to the real QRD diffuser. Wir setzen das modifizierte QRD-Design bei unserem auf Mobilität ausgelegten QR-36 ECO Diffusor ein.
Which diffuser is right for me? 49 or 36 chambers?
The QR-49 PRO models are high-end QRD diffusors and are always the first choice in terms of sound. They have a weight of approx. 3.2 kg. Der QR-36 ECO hingegen ist mit seinem Gewicht von nur ca. 2 kg speziell für mobile Übertragungswagen, mobile Recordingstudios oder ähnliche Anwendungen ge, where weight plays a decisive role. Here, the low weight is given priority over the sound properties.
What are first reflections?
First reflections are those vibrations that first hit a wall and are reflected back to the ear. These reflections can massively influence the direct sound of the loudspeakers. The result is overemphasis or cancellation of certain frequencies and thus an enormous influence or distortion of the sound. First reflections occur at the walls, the ceiling and the floor. They should be dispersed by diffusers or absorbed by absorbers.
How to locate first reflection points?
Sound waves are reflected by walls. So when the sound hits a wall it is reflected back. These reflections work according to a simple principle: angle of incidence = angle of reflection.
A simple and accurate method to find the critical points of the initial reflections is the mirror method: You sit down on your listening position and have someone walk flat along the wall with a mirror. When you can see the front of the speaker in the mirror, you have found the position where you should act against the first reflections. This method is done for the left speaker against the left wall and the right speaker against the right wall. The mirror method can be used both on the wall and on the ceiling and in virtually any room situation.
Reverberation time
In addition to suppressing initial reflections, the reverberation time in the room is also important. This is usually specified with the value RT60 (Reverb Time 60). This value indicates how many seconds the reverberation takes to decay by 60 dB in relation to the output level. In control rooms of recording studios, a very short reverberation time with an RT60 value of approx. 0.25 - 0.3 seconds has become established. In HiFi rooms and home cinemas, on the other hand, the reverberation time should be about 0.5 seconds.
To reduce the reverberation time, broadband absorbers are recommended because they are effective over a wide frequency range. Rooms with extremely short reverberation times (< 0.5 seconds) are perceived by some people as very unpleasant, in this respect absorbers should be used very selectively.
What is the LEDE principle?
LEDE is the abbreviation for "Live End Dead End". This principle is often used in control rooms of recording studios as a basis for acoustic optimization. Here, the front half of the room around the monitoring speakers is acoustically damped, while in the rear half of the room, around the monitoring position, the sound is diffusely reflected, thus increasing the diffusivity.
Adelsklang® 2025. If you have any questions about our products, please contact us at support@adelsklang.com
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