Time Domain measurements?

[fosti]

I will read that, but do you think, that Sony and Philips have been so wrong by choosing the 16bit 44kHz bandlimited to 21kHz format for a CD standard?

 

[haraldo]

No, because even if Vinyl or bandmachines even could record beyond 20kHz if you might hear a difference, I don't believe so

what happens beyond 20KHz is important and makes an audible difference too, for everyone !
Our ears are not microphones!

F. Alton Everest writes following in Master Handbook of Acoustics, 6th edition page 64:
Plug one oscillator into the left channel and the other into the right channel and adjust both channels for an equal and comfortable volume level at some midband frequency. Then tune the oscillator to 23 KHz and the other to 24 KHz without changing the level settings. With either oscillator alone nothing is heard because the signal is outside the range of the ear. However if the tweeters are good enough you might hear a distinct 1 KHz tone.

The 1 KHz tone is the difference between 23 Khz and 24KHz. The sum 47 KHz is another sideband. Such sum and difference sidebands are generated whenever two pure tones are mixed in a nonlinear environment. The nonlinear environment in this case is the middle and inner ear. In addition to intermodulation products, the nonlinearity of the ear generates new harmonics that are not present in the sound falling on the eardrum.

 

[haraldo]

I will read that, but do you think, that Sony and Philips have been so wrong by choosing the 16bit 44kHz bandlimited to 21kHz format for a CD standard?

Yes, I do!

 

[fosti]

Then you will spend a lot of money for nothing, but someone will collect it for selling emotions like in the automotive industry. Best luck!

Can you show me or publish a frequency response (better a transfer function) of a Studer bandmachine?

 

[haraldo]

Then you will spend a lot of money for nothing, but someone will collect it for selling emotions like in the automotive industry. Best luck!

Can you show me a frequency response (better a transfer function) of a Studer bandmachine?

No I can´t but I know some people around here that do have Studer pro bandmachines
maybe there is a chance to listen ... but I never seen transfer functions ....

I trust my ears and I never yet threw money out the window on audio gear

 

[fosti]

......
I trust my ears and I never yet threw money out the window on audio gear

Double blinded? "If you don't do it blinded I don't care what you think!" (Quote from Toole or Olive)
Cables for example can have a "character" or "sounding" ....but if so, they are wrong! The should be neutral!

 

[haraldo]

Double blinded? "If you don't do it blinded I don't care what you think!" (Quote from Toole or Olive)
Cables for example can have a "character" or "sounding" ....but if so, they are wrong! The should be neutral!

My goal in life is not to make you happy
My goal is to have magical musical experiences .... it is quite simple to me, really

 

[Joachim Gerhard]

You think you know what you are talking about with 5o years of experience???? I'm not sure you are!

? Is it the language?

 

[fosti]

Me too....and I think it is important to have an argument, that not all people believe what you (haraldo) or J think is true.

 

[fosti]

? Is it the language?

Einmal durch deepl.com "gejagt"
"Sie glauben mit 5o Jahren Erfahrung zu wissen, wovon Sie sprechen??? Ich bin mir nicht sicher, ob Sie es wissen!"
Ja das meinte ich!

 

[fosti]

That was in context with his meaning about Ncores and other switching amplifiers. Tell me what is "nicht richtig" about me or what is "nicht richtig" about J's meaning?

 

[tuga]

Me too....and I think it is important to have an argument, that not all people believe what you (haraldo) or J think is true.

Since you've brought up the subject of belief, do you think that people should renounce their own lesser gods for yours (T&O)?

 

[Joachim Gerhard]

That was in context with his meaning about Ncores and other switching amplifiers. Tell me what is "nicht richtig" about me or what is "nicht richtig" about J's meaning?

They have a filter at the output, am I right ?

 

[fosti]

The video I have linked is quite scientific......I'm a scientist, not a story teller!

 

[fosti]

They have a filter at the output, am I right ?

True, but as we know, an already bandlimited signal does not get more "artifacts" (there are no!) even if we make a 10 times or a 100 times slope through it!

 

[fosti]

what happens beyond 20KHz is important and makes an audible difference too, for everyone !
Our ears are not microphones!

F. Alton Everest writes following in Master Handbook of Acoustics, 6th edition page 64:
Plug one oscillator into the left channel and the other into the right channel and adjust both channels for an equal and comfortable volume level at some midband frequency. Then tune the oscillator to 23 KHz and the other to 24 KHz without changing the level settings. With either oscillator alone nothing is heard because the signal is outside the range of the ear. However if the tweeters are good enough you might hear a distinct 1 KHz tone.

The 1 KHz tone is the difference between 23 Khz and 24KHz. The sum 47 KHz is another sideband. Such sum and difference sidebands are generated whenever two pure tones are mixed in a nonlinear environment. The nonlinear environment in this case is the middle and inner ear. In addition to intermodulation products, the nonlinearity of the ear generates new harmonics that are not present in the sound falling on the eardrum.

1 kHz sideband yes, 47 kHz no talk about it ......and with pure sinusodials again yes or maybe. But was does it have to do with listening to recordings of music? And even a small 1/2" tweeter will beam at frequencies above 20 kHz such a lot, that this experiment is almost irrelevant!

 

[fosti]

Attached explanation from Cyril Hammer

The diagrams are OK, but to stay with the CD example -16° phase shift at 20 kHz - you won't hear out, let alone bet the house and yard! He talks zero about the much more relevant group delay behaviour and their hearing thresholds...let alone hearing thresholds at all.

 

[Joachim Gerhard]

When you listen with this Ncore amp to CD quality the response will be down -0,6dB at 20kHz. I can here a sine tone only to 14kHz, so for me it may not matter.

 

[haraldo]

1 kHz sideband yes, 47 kHz no talk about it ......and with pure sinusodials again yes or maybe. But was does it have to do with listening to recordings of music? And even a small 1/2" tweeter will beam at frequencies above 20 kHz such a lot, that this experiment is almost irrelevant!

F Alton Everest claim that signals above 20KHz is audible through the subharmonics... if you cut these high frequencies through brickwall filter, the subharmonics that you can hear will also disappear; which means you lose audible artifacts within the music... That's not my claim. It's the way to understand the writings of F. Alton Everest, author of Master Handbook of Acoustics.

Maybe I am wrong, but this is very clear in his book!

 

[ctrl]

Wow! Where to start...

According to a whitepaper I read by Cyril Hammer at Soulution Audio, he states following:
- an amplifier with a bandwidth of 20 KHz (-3dB) has a phaseshift of 45 ° at 20 KHz, very audible.....

In his whitepaper he gives an example of sine waves with 1kHz and 2kHz and the resulting signal. Then the phase of one sine signal is changed by an unknown amount and again the resulting signal is shown (red curve):

Apart from the fact that the human ear/brain does not hear in this way, let us assume that his statement has some relevance.

Then the result would look really bad - the "character" of the original signal has changed significantly due to the phase shift. But he did not tell us how big the phase shift was and if it was realistic.

To check this we take a look at the data given by Cyril Hammer himself (and what @haraldo quoted) about the phase-shift when using a low-pass (for bandwidth limitation):

Let's take the worst case, as quoted by @haraldo with a first order lowpass at 20kHz.
The phase shift at 1kHz, 2kHz and 20kHz is represented by the purple circles.

Now we can judge whether the above example of phase shifting is realistic. According to his diagram the phase shift is about 3 degrees between 1kHz and 2kHz.
So let's turn on the oscilloscope and see what happens at 3 degrees phase shift.

The "character" of the signal changes (with 3deg phase-shift) practically not at all. The example shown above has nothing to do with reality.

Okay, at 1kHz and 2kHz the bandwidth limitation may not matter, but if we look at 2kHz and 20kHz, it certainly does!

Between 2kHz and 20kHz the phase-shift is about 40 degrees, which is quite a lot - but does it also change the "character" of the combined signal?

Also here practically no change, the 20kHz signal is only slightly shifted in time on the "carrier wave".

The 1 KHz tone is the difference between 23 Khz and 24KHz. The sum 47 KHz is another sideband. Such sum and difference sidebands are generated whenever two pure tones are mixed in a nonlinear environment. The nonlinear environment in this case is the middle and inner ear. In addition to intermodulation products, the nonlinearity of the ear generates new harmonics that are not present in the sound falling on the eardrum.....
F Alton Everest claim that signals above 20KHz is audible through the subharmonics... if you cut these high frequencies through brickwall filter, the subharmonics that you can hear will also disappear; which means you lose audible artifacts within the music... That's not my claim. It's the way to understand the writings of F. Alton Everest, author of Master Handbook of Acoustics.

A music signal does not correspond to "white noise", but the sound pressure decreases steadily at high frequencies on average. Signals above 15kHz are in mostly 10-20dB below RMS (my guess, does anyone know more?).

The "perceived sound pressure" of the quadratic distortion produced in the hearing system in the example quoted by @haraldo was determined by Zwicker. This distortion is about -40dB when the frequencies f1 and f2 are at 90dB.

But if you consider how much the super high frequency is lowered in sound pressure compared to the average music signal, the quadratic distortion produced in the hearing system should fall below the threshold of audibility.

Source: Zwicker, Fastl - Psychoacoustiks, Chapter 14 "The Ear’s Own Nonlinear Distortion"

This means that the effect of quadratic distortion produced in the hearing system of this subject (and many other subjects) follows approximately the relatively simple rule that is indicated by the broken lines. This rule corresponds to what is expected for a transmission system, that acts with an ideal quadratic distortion. The characteristic, expressed by the broken lines, follows the equation

L (f 2 − f 1 ) = L 1 + L 2 − 130 dB . (14.4)

The fact that the two parts of Fig. 14.2 can be described well by the same set of dashed lines indicates that, in this case, the nonlinearity is independent of frequency distance. This means that the transmission characteristic of the hearing system of such a subject differs relatively little from regularity.

For lower values of the primaries, the difference tone remains inaudible. For L 1 ≈ L 2 = 70 dB, the cancellation level remains at about 10 dB. This means that it is 60 dB below the level of the primaries, corresponding to an amplitude of the sound pressure of the cancellation tone of about one thousandth that of the primaries. This difference becomes smaller for increasing level of the primaries and reaches about 40 dB (corresponding to 1%) for L 1 ≈ L 2 = 90 dB.