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  1. Pinox67

    THD Measurement: Do it represent the actual nonlinear harmonic distortion?

    For those who have access to AES publications, here you will find an in-depth analysis (in terms of mathematical models and simulation results) of the topics discussed in this thread. It is not an easy read...
  2. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    I'm preparing simulations to answer these questions. It will take a bit 'of time...
  3. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    I have already answered on the relationship between aspects related to ITD/ILD and transient steepness: the latter changes the flow of information that reaches our brain to process spatial information. Your reasoning is correct if we analyze the signal in its entirety. But our ear doesn't know...
  4. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    You break through an open door with me...:) In my studies I have always tried to run tests with "music-like" signals (you can find an example in this link). But to highlight phenomena, it is always necessary to start from simple signals.
  5. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    Good question. ITD and ILD are based on an operation analogous to a cross-correlation between the signals that reach the brain from our two ears. Now, any phase shift between the channels of the ITD value, let's say about 5usec which corresponds to 1 sample for a 192KHz sampling, can be...
  6. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    I think there is some confusion. One thing is that for a signal limited in audio bandwidth, the sampling rate of 44KHz is able to reproduce with high precision the instant in which a transient occurs (110psec, although I should elaborate on how this value is calculated), which exceeds the level...
  7. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    I can't find the main articles on the fly. However you can search the web for "Interaural Time Difference" (or Level). As already reported, you can also find a lot in good psychoacoustic books. A very interesting one that I suggest is "Principle of Cognitive Neuroscience", by D. Purves and...
  8. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    Correct, the temporal aspects of the transients are preserved in this case. I ran some simulations too.
  9. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    If you read the texts that talk about these experiments, you can see that the ITD/ILD values that we are able to detect depends on several aspects, such as the frequencies in the sound, spectral complexity, background noise. And it doesn't seem like a surprise to me.
  10. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    This is something that puzzled me too at first. The 20KHz bandwidth is related to the spectral analysis of the sound performed by the cochlea, to determine its "timbre". But for localization aspects, for which signal time arrival and differential time/or signal levels between ears (ITD and ILD)...
  11. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    Even when I listen to music in the car or with the iPod, I can hardly tell if it's mp3 quality (naturally with little compression) or CD, and I'm happy about it. But these are not listens that I consider "quality". Comparisons must be made on quality playback chain, controlled environments and...
  12. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    Yes, I had already seen this interesting video some time ago. But the theme here is slightly different: we are talking about the time spread of transients when switching from signals with a high sampling frequency to a lower one and the fact that our auditory system could detect this effect in...
  13. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    It's certainly not me... it's what you find in scientific texts that talk about these aspects.
  14. Pinox67

    Is high-resolution audio audible or not audible and a waste of data?

    I have found several sites, articles and tests on the web in which it is claimed that the CD quality music distribution format, 16bit/44KHz, is more than sufficient to preserve practically all the characteristics of the sound compared to higher resolution formats. 24bit/sample and higher sample...
  15. Pinox67

    THD Measurement: Do it represent the actual nonlinear harmonic distortion?

    A friend pointed out some problems to me in the post#46 about dynamic model simulations. On a later review of the model implementation, I indeed found a calculation error that skewed some results. So I rewrote most of the post, making the necessary corrections. The conclusions are no so...
  16. Pinox67

    THD Measurement: Do it represent the actual nonlinear harmonic distortion?

    Thanks for the detailed integration to the description of static and dynamic systems, I appreciate your accuracy. I updated the nomenclature in the post for more clarity. The model described in the post is certainly not original, it is widely used to model non-linear systems with memory and for...
  17. Pinox67

    THD Measurement: Do it represent the actual nonlinear harmonic distortion?

    Transistors have an exponential transfer function. In one section of this post I looked at what happens in these cases. It must be said that the resulting distortions heavily depend on the type of circuit in which the active elements are inserted so that, for a "black-box" modeling, one can only...
  18. Pinox67

    THD Measurement: Do it represent the actual nonlinear harmonic distortion?

    [EDIT Thu 1 Dec, 2022] In my studies I have developed models for more general cases of nonlinear systems with memory effects, more representative of real audio amplifiers. Won by curiosity, I have also investigated the trend of THD and other indicators also for these cases, deriving a method to...
  19. Pinox67

    Physics and perception of low-order nonlinear distortions

    So, transposing your analysis into the world of nonlinear distortions, this would imply a distortion level of 3rd harmonic at -30dB to have a contribution of -20dB on the fundamental (from fig. 10a you can see that HD1 is 10dB higher than HD3, at least in the static model) so that the modulation...
  20. Pinox67

    Physics and perception of low-order nonlinear distortions

    On the relationships between the non-linearities of our devices (small or modest, not easily modelable) and the non-linearities of our auditory system (highly non-linear) there is still room for exploration. The important thing is to do it with a scientific approach. And in this field it is not...
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