Audiobuben Lieutenant Schmidt: A few words about fractals, diffusers and wonders suggestion

Yes, that's right, we will talk about fractal diffusers, the most magical dodecahedrons, trapezoids, pyramids, parallelepipeds and other volumetric geometric figures that are actively introduced into the practice of audiophile "acoustics."



To begin with, a lot has been written about the “wonderful” properties of magical pyramids, and the people who write about it refer to them differently. Some are sincerely convinced that fractal diffusers work and absorb “harmful secondary vibrations”, improving the divine sound, others desperately prove that this is a particular version of the placebo.







This post is addressed both to consumers who have not yet come across this unique way of “defeating harmful vibrations”, as well as those who ate the dog at the debunking of audiophies. In the process of narration, I will try to understand whether this can work, and what mechanism makes the consumer feel an effect that does not exist.



So that the post is not considered as an attempt to inflict reputational damage on one or another vendor, retailer and manufacturer, I will describe “spherical fractal diffusers in an abstract audiophile environment” without mentioning brands, manufacturers, etc.



Version 2 (updated and corrected)



Audio deception - as the essence of the method of fractal diffusion



According to the manufacturers of diffusers, the effect of their use is based on the methods of fractal marketing of the subject matter. Manufacturers of such “devices” claim that, due to their shape, these pieces are able to suppress secondary radiation from sound sources, which significantly affects the fidelity of reproduction. Thus, these wonderful devices absorb “harmful” vibrations and make the sound “cleaner” and “more detailed”. As part of the discussion about the benefits of fractal diffusers, it is noted that the power supply system and dynamic loudspeakers are sources of vibrations that are harmful to the sound.



Frankly speaking, I, like most of the potential users of this “improved”, have no practical experience in vibration isolation, sound engineering and a doctoral degree in mathematics. I, not having heard the magic effect of the miracle trapezium, turned to the original sources, on the basis of which the theory of their working capacity was created. So Mandelbrot gave a precise definition of a fractal, defining what this term means:



a geometric figure with a property of self-similarity, that is, composed of several parts, each of which is similar to the entire figure as a whole.


How the study of Mandelbrot helped the creators of the audio facility is not yet clear. But it can be assumed that the use of the geometric principle in creating a physical object somehow reflects on its acoustic properties and ability to absorb vibration. Below we will discuss the methods used to combat low-frequency and high-frequency vibrations that will help to verify this.



Next on the diffuser. In hydro and aerodynamics a diffuser is called -



the part of the channel (pipe) in which the flow slows down (expansion).


Probably, some properties of such a diffuser were the reason why placebo pyramids were so named.



In electroacoustics, the diffuser is:



part of the mechanical oscillatory system of a loudspeaker designed to excite sound waves in the ambient air.


Anyway, these diffusers have nothing to do with fractals and geometry.



Further, the search led me to addressing the issues of vibration protection, which I already had to write in a post about spikes. It turned out that in addition to the Umov Poynting vector and the law of conservation of energy, which I cited as arguments of the inoperability of thorns as a vibration isolator, there is still a lot of interesting things there.



In particular, people professionally engaged in shock-wave processes describe five basic principles of protection against harmful vibrations (depending on the frequency, certain methods are used):



1) wave attenuation through reflection. Apply a sharp change in the geometric and mechanical properties of the element of the vibrating structure. (can be used conical elements, changes in density, stiffness and elasticity of materials, etc.). Fading occurs inside the damping element due to its properties. For example, a layered cake with sequential multiple repetition of layers of steel, copper and aluminum (the principle on which is hinted at, in some audio bearings, but considering the number of layers, the effect is noticeable within the statistical error of the author's note). The fractal diffuser does not use this principle.



2) concentrated masses, as a variation of the first method; And this principle is also not used in the fractal diffuser.



3) The use of G and U-shaped structural elements for the transformation of longitudinal waves. Used in core parts. Very far from fractal diffusers.



4) The use of parts with high internal friction of extruded materials and wire-mess; Unlike fractal diffusers.



5) The use of materials and elements with internal damping - rubber, latex, spring shock absorbers, etc. n. And there is nothing in common with fractal diffusers.


In addition, these principles have nothing in common with fractal mathematics, which, according to manufacturers of diffusers, should somehow help with changing the sound and cleansing it from harmful, incoherent vibrations. Specialists who claim that diffusers cannot work by definition also refer to the work of such remarkable people as Kirchhoff, Tymoshenko, Lyav, Reysnner, who made a great contribution to the creation of the principles described above.



What sound can do with fractal diffusers



Despite the foregoing, audioforums are full of topics with discussions of the effects of diffusers, which can hardly be considered a deliberately created excitement. According to numerous reviews, you can trace the general points in the reviews of such effects. Most of those who noticed changes from fractal homeopathy wrote that pyramids affect the high-frequency spectrum.



It is not difficult to understand that the “diffuser”, installed on the upper part of the AU, plays the role of a peculiar sound-scattering device, mainly due to the reflection of HF waves from the ribbed surface of the “device”. Subtle changes in the frequency spectrum, determined by a trained “golden” ear, are the reason for such statements.



Fractal diffusers cannot and should not do anything more significant with sound. At the same time, in a number of hard cases, users of “improvers” note much more impressive changes and enthusiastically speak of these, it is about them that will be discussed in the next section.



Autosuggestion - from fractal illusion to fractal diffusion



Many good things, quite sincerely, without a second thought, and jeans write audiophiles about fractal diffusers, which is the result of a so-called. autosuggestion. In other words, the consumer feels the need to improve the sound, not having the opportunity to purchase equipment that allows you to achieve this. Reading the numerous comments on the effectiveness of the “device” and the statement of “authoritative” experts about the efficiency of the method creates an anticipation of the effect.



After this, the victim of “fractal diffusion” visits a shop, a showroom or friends who already have this wonderful thing and are testing it in practice. The conviction that this should work creates the illusion of effect. If on the fifth day after the purchase, the diffusers are removed from the speakers and blindfolded to the music lover, he most likely will not determine their absence by ear. The scattering effect, which they can actually create, is negligible, due to the area of ​​the fractal diffuser itself.



The technology is simple to ugliness. If the client’s mind is labile enough, and the suggestibility is high enough to “feel” the effect, he will notice it in the showroom, buy the “thing”, and be happy with the illusion. If not, he will question the effectiveness of the principle at the stage of viewing the advertisement and will not even test it in practice.



Another moment, the need for improving the quality of the tract, as a rule, is also suggested. And this happens thanks to the banal human envy. I saw a diffuser from a friend, was impressed with the sound quality and that's it. The instilled need, in some cases even stronger than that which arose without suggestive influence, for which thanks to advertising psychologists, marketing specialists and PR-technologists.



Concerning the appearance of such illusions, it is well described in the cult Soviet popular science film “I and Others”, where the effects of suggestion are demonstrated through social approval. In this situation, something very similar happens. The well-known principle for the formation of subjective value works, which can be expressed with the following phrase: “If people close to me in their interests say that the effect of“ fractal diffusion ”is, then this is indeed the case.”



Total



The myth of fractal diffusers that has been repeatedly debunked before me remains a myth, since there is not a single objective proof of the performance of such “improvers”. The credibility of manufacturers' statements about the physical properties of these objects is equivalent to the prophecies of Globa and Vanga. The fractal principle is used in the design of the object, but does not significantly affect the acoustic properties.



Diffusers are able to change the sound, like any other object with a ribbed surface, as a diffuser. The abundance of information about the effectiveness of fractal diffusion with high probability is the result of self-suggestion of their users. Such reviews, given their independence and subjective honesty, act as an engine of sales and relieve the manufacturers of "improvers" from the need to conduct large-scale advertising campaigns.



I understand that there may be other opinions on the issue described in the post, so I will be glad to have a lively discussion in the comments.



Photo material used: melchermax



By the way, due to the fact that fractal diffusers are in demand, they are in our catalog.



The opinion of the author in this case is his subjective position, and not the position of the company Pult, due to the lack of experimental data on the effects of the device.



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