You do not understand, probably language problem. These people understand the effects group delay more than you think. What they question is your using irrelevant data and wrong ideas to show a known fact.
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To show the known fact of what? Are there speed distortions in the first period? In real music signals?
If all the components of these "speed distortions" are high above the acoustic region, then they are simply irrelevant to the sound reproduction. The start of a sinusoidal signal from zero at the zero crossing point is an "infinitely" fast transition phenomenon. So you have to use an infinitely fast amplifier. This is the whole "discovery" ..And the best even infinitely linear, completely noise-free, with zero output impedance, unconditionally stable with complex loads ... Good luck.
A simple model of a distorsionless ( non-linear ) power amplifier could be a low pass filter with gain. Some non-minumum phase effect are missing but would probably be at quite high frequency.
If we then send a test signal with components above the low pass of the amp we would not get the same signal out because of low pass filtering.
If we then send a test signal with components above the low pass of the amp we would not get the same signal out because of low pass filtering.
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You seem to have serious language issue. As I told you before, this fact :
I don't know if you will understand this or not but to make a valid proof, real measurement is required, simulation result alone is not enough. Use real signals present in an audio recording. Avoid use of hypothetical signals.
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can 19 and 20 kHz signals from the standard IMD test be used?
Attachments
So I could finally read your paper and my conclusion is that there are many things that I can't support.
Saying f.i. that linear circuits can produce distortion is not my definition of distortion.
Then you show a multitone test of amp 3 that looks bad.
A direct question would be, how about lower levels an no input at all, that would have been the way to investigate,
That would have started the interesting discussion I had hoped for.
Suppose that with no input signal the noise spectrum would have been the same.
But no, not going into any depth, big disappointment.
Then the statement that humans are most sensitive to phase errors.
Since many years psychoacoustic institutes have tested this and the result is that in the most sensitive 1-3Khz region we can detect ca 2msec delay, much more than you would expect, so change of timbre in the low micro second and below region, very doubtful and unlikely.
At LF and HF threshold is even 20msec because at HF we are not even phase sensitive.
So that corresponds in no way with your assertation, bad research !
Nice images do not prove anything on audio perception.
Sorry, I did my best, but I was hoping for new insights.
Hans
Saying f.i. that linear circuits can produce distortion is not my definition of distortion.
Then you show a multitone test of amp 3 that looks bad.
A direct question would be, how about lower levels an no input at all, that would have been the way to investigate,
That would have started the interesting discussion I had hoped for.
Suppose that with no input signal the noise spectrum would have been the same.
But no, not going into any depth, big disappointment.
Then the statement that humans are most sensitive to phase errors.
Since many years psychoacoustic institutes have tested this and the result is that in the most sensitive 1-3Khz region we can detect ca 2msec delay, much more than you would expect, so change of timbre in the low micro second and below region, very doubtful and unlikely.
At LF and HF threshold is even 20msec because at HF we are not even phase sensitive.
So that corresponds in no way with your assertation, bad research !
Nice images do not prove anything on audio perception.
Sorry, I did my best, but I was hoping for new insights.
Hans
Hans, I borrowed figures 4-6 from Bukvarev's test (see link).
Is it really incomprehensible that the increase in noise at the end of the audio range is due to high-order intermodulation products.
Hiraga showed a similar effect in the article "The Many faces of distortion" Glass Audio 2005-05 see fig. 3 and comments
I'm not going to convince anyone, you can pour from empty to empty endlessly. Whoever understands will be guided in practice and will soon be convinced of the correctness of the idea of reducing Gdelay to 100 ns and below, that's all. Of course, subject to the conditions that I stipulated.
Is it really incomprehensible that the increase in noise at the end of the audio range is due to high-order intermodulation products.
Hiraga showed a similar effect in the article "The Many faces of distortion" Glass Audio 2005-05 see fig. 3 and comments
I'm not going to convince anyone, you can pour from empty to empty endlessly. Whoever understands will be guided in practice and will soon be convinced of the correctness of the idea of reducing Gdelay to 100 ns and below, that's all. Of course, subject to the conditions that I stipulated.
A simple way to remember the difference between linear and non-linear distortion is to realize that linear distortion does not create harmonics.
Linear distortion like non-flat frequency response and phase shift do not create harmonics and can result from equipment consisting of perfectly linear, ideal components.
Non-linear distortion results from components that are non-linear and that will create harmonics.
Note also that the difference between harmonic distortion (THD) and intermodulation distortion (IMD) is only due to the way they are measured. They are both the result of the exact same non-linearity in the equipment. The various test methods, like THD, IMD, DIM-30 etc. all measure the same non-linearity but in different ways and are developed in an attempt to find a test method that correlates with listening tests.
Jan
Linear distortion like non-flat frequency response and phase shift do not create harmonics and can result from equipment consisting of perfectly linear, ideal components.
Non-linear distortion results from components that are non-linear and that will create harmonics.
Note also that the difference between harmonic distortion (THD) and intermodulation distortion (IMD) is only due to the way they are measured. They are both the result of the exact same non-linearity in the equipment. The various test methods, like THD, IMD, DIM-30 etc. all measure the same non-linearity but in different ways and are developed in an attempt to find a test method that correlates with listening tests.
Jan
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I guess the question is if we se linear distortion caused by the low pass of the amplifier as distortion, given it's above lets say 100kHz.
/örjan
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