In the reviews and subjective assessments of sound equipment, there are terms that are rarely used by audio engineers. Especially often they relate to the dynamic characteristics that have become the field for numerous scientific speculations.
Such words as macro and microdynamics are used, and, as an analogue of the latter, the term detail is used. The terms thereof, according to the people who use them, testify to fidelity of reproduction and are almost the main criteria for its assessment.
It happens that different authors understand different things by these words, sometimes they don’t bother themselves with explaining what they mean by, for example, “microdynamics”. In other words, they brazenly speculate with scientific vocabulary. As a rule, the opuses in which such usage is found have an explicit or hidden commercial purpose.
In connection with such cases, I want to write about what exactly psychoacoustics experts and experts mean by macro and microdynamics. And besides, tell about what measurable indicators will indirectly indicate these undocumented properties of sound.
A little bit about speculation or the devil in little things
Usually, manufacturers whose equipment does not have real advantages resort to the substitution of concepts or outright lies. In addition, there is a well-known technique, when inadequate prices for a product are justified with a scientific nonsense. There are often cases with people who position themselves as experts, but do not have relevant competencies.
In such cases, undocumented and subjective characteristics are very convenient dust, which can powder the eyes of even an experienced music lover. Microdynamic stories are a particularly frequent tool for unscrupulous vendors, “experts,” and marketers.
When it comes to dynamic characteristics, stories begin that an experienced expert with trained ears is able to distinguish “the smallest nuances” that fundamentally change everything in the sound of the test work, and accordingly, it makes sense to pay on top of 10.5 million (and even sometimes not rubles) ).
Then begins the tales of the Viennese forest about the compensating properties of “cheap”, bad audio tracks. Further, in the event that a case occurs in a showroom, the client is solvent and suggestible, something with improved “macro” and “microdynamics” and high “detail” is passed to him. At the same time, they may not smell there.
And everything seems to be correct, since quite a few nuances really depend on the dynamic characteristics, and compression, i.e. amplitude limit - really able to change the sound of the work. But, if you clarify the "expert" about what exactly the nuances are in question, he is unlikely to answer anything intelligible. Terminological speculators are particularly fond of microdynamics, since, in their opinion, it cannot be measured, unlike “macro”, which has measurable counterparts.
Dynamic characteristics and their evaluation
Sound engineers and psychoacoustics researchers relatively rarely use the terms “macrodynamics” and “microdynamics”. Each of these words, as a rule, implies several dynamic parameters at once, which together allow us to create an idea of the dynamic capabilities of a path or component.
Those. in reality, both of these terms make it possible to understand how well devices are capable of transmitting amplitude differences during playback. The division into micro and macro is rather conditional, and the terms themselves are not strictly scientific and are rather used to simplify complex concepts, which allows them to successfully speculate.
MacrodynamicsWhere speculation does not occur, macrodynamics is usually understood as the dynamic range and attack. I suppose you do not need to be a graduated physicist to understand that these characteristics are measurable and have quite specific definitions for themselves.
Dynamic range - the difference between the loudest and quietest sound that the system is capable of reproducing. It is measured in dB.
A quantitative assessment of this indicator is considered to be the maximum sound pressure level (maxSPL). It is calculated by the formula:
max SPL = S + 10 lg P / Po,
(where S is the characteristic sensitivity, dB / W / m; P - short-term (musical) power, W; Po - 1 W).
This parameter is especially critical for reproducing symphonic and chamber classics. When recording such works, a wide dynamic range is used, since it is important for the correct perception of the work, the transfer of the author's intention and the features of the performing interpretation.
In modern genres, sound engineers often use compression and deliberately adjust recordings to the dynamic capabilities of the average instrument.
In cases with insufficient dynamic range, the work will not sound impressively, due to the erasure of dynamic differences.
The attack is the first impulse of sound reproduction, as well as the characteristic of the increase in amplitude to the maximum value. In paths with a bad attack, jerky sounds can merge. It is clearly seen when playing technically heavy genres with a high density of drums, an abundance of cymbals, etc.
MicrodynamicsMicrodynamics is a bit more confusing. A number of authors using this term believe that microdynamics is:
“The ability of the system to accurately reproduce quiet sounds”;
“The rate of rise of the signal for quiet sounds”;
“Analogue of detail”.
Others write that it is simple:
“Audibility of subtle nuances”
(what exactly is not specified).
Despite the inaccuracy of the definitions that differ from each other, microdynamics periodically appears as a subjective criterion in the path evaluation systems and acoustic systems. For example, Fast Sound Quality (FSQ) - for the evaluation of car audio, which was developed by a professional sound engineer, the head of the Acoustic Center of the Department of Broadcasting and Electroacoustics of MTUSI DG Svoboda.
I met quite clear, transparent, high-tech and useful definitions of microdynamics, of which I formulated the following:
Microdynamics is a characteristic reflecting the rate of rise of the signal front when playing one or more instruments, as well as other sounds at the lower limit of the dynamic range in a particular piece of music.
At the hardware level, many authors directly associate microdynamics with the rate of rise of the output voltage of the operational amplifier used at the input provided. The higher this speed, the better the micro dynamics, like other dynamic characteristics.
As test signals for the subjective assessment, recordings that are teeming with bow-slip sounds along the strings or the sounds of plucked movements when played on an acoustic guitar are suitable. That is, as in the case of macrodynamics, the ideal test material will be academic symphonic and chamber instrumentals.
DetailTogether with microdynamics, and also instead of this term, the term “detail” is used, by which, as a rule, we mean the linearity of the transfer characteristic. And then everything becomes completely transparent, since THD and IMD have been used to evaluate this parameter for a long time and effectively, i.e. quite measurable characteristics.
Dry residue
From the above, we can conclude that the detail and macrodynamics are quite measurable characteristics. They can be judged on the basis of measured and documented parameters, namely SPL (macrodynamics), THD and IMD (detail). Microdynamics reflects the fidelity of playing sounds at the lower limit of the dynamic range.
When choosing, it does not require expert listening (anyone can define a subjectively comfortable level of microdynamic capabilities using a quality recording of a string quartet). The technical parameter reflecting the microdynamic capabilities of the UMZCH is the rate of increase of the output voltage of the operational amplifier at the input of the pre-amplification module.