Interesting you should think of it that way
I don't know my limits on pure tones, but I'd be surprised if I can still hear above 15k - tinitius is my friend
However
I can hear the effects of different DAC filters (not all filters of course). These are all operating and having effects above 15k and therefore by your argument are inaudible. I spend a lot of my time standing behind live orchestras and by heck can I hear the difference between live cymbals and gongs and poorly reporoduced cymbals and gongs (which I hear all too often)
From any engineering design point of view we must sensibly handle something outside the audio band so that it has no effect within the audio band. Saying 'I can't hear above 15kHz' is far too simplistic. On the other hand having a 1MHz transducer when there is no input signal at that freqeuncy (unless it's a distortion artefact) is probably going a little too far the other way
BTW, when I was a teenager I could hear pure tones up to 22kHz - why should a system be designed that's right for an older generation but wrong for younger ears? Why do we have to accept a bad compromise?
This is all so off topic
Goto,
You might remember that I was the one who wrote
A completely different point is that the "Ultra Tweeter" that StigErik linked to doesn't *reproduce* ultrasound, it supposedly works by "quantum mechanically modifying the air molecules" using microwaves, to affect how audible frequencies get reproduced. Total audiophile voodoo, of course, but at least it theoretically illustrates how HF signals *that are not part of the original signal* can affect audible frequencies. But as long as you make sure there isn't some sort of ultra-high-frequency intermodulation going on, theer is of course no need for the ncore amps to reproduce anything above 100k...
You might remember that I was the one who wrote
A completely different point is that the "Ultra Tweeter" that StigErik linked to doesn't *reproduce* ultrasound, it supposedly works by "quantum mechanically modifying the air molecules" using microwaves, to affect how audible frequencies get reproduced. Total audiophile voodoo, of course, but at least it theoretically illustrates how HF signals *that are not part of the original signal* can affect audible frequencies. But as long as you make sure there isn't some sort of ultra-high-frequency intermodulation going on, theer is of course no need for the ncore amps to reproduce anything above 100k...
The device I linked to that started this discussion operates above 1 GHz.... Gigahertz, 1.000.000.000 Hz.
There is no need to feed the device with a 1 GHz signal, as the output is generated in the device... if I understand it correctly. It should be able to cook a chicken during just 4-5 Justin Bieber tracks at full volume.
Linear supply and we had two monoblocs with SMPS but could not use them because the owner had reduced the gain for use with his 112 db speakers.
Sounds like something is wrong. I have NC400 with SMPS and it only gets lukewarm, even without external cooling.
Interesting you should think of it that way
I don't know my limits on pure tones, but I'd be surprised if I can still hear above 15k - tinitius is my friend
However
I can hear the effects of different DAC filters (not all filters of course). These are all operating and having effects above 15k and therefore by your argument are inaudible. I spend a lot of my time standing behind live orchestras and by heck can I hear the difference between live cymbals and gongs and poorly reporoduced cymbals and gongs (which I hear all too often)
From any engineering design point of view we must sensibly handle something outside the audio band so that it has no effect within the audio band. Saying 'I can't hear above 15kHz' is far too simplistic. On the other hand having a 1MHz transducer when there is no input signal at that freqeuncy (unless it's a distortion artefact) is probably going a little too far the other way
BTW, when I was a teenager I could hear pure tones up to 22kHz - why should a system be designed that's right for an older generation but wrong for younger ears? Why do we have to accept a bad compromise?
This is all so off topic
Yes, we are digressing, so one final comment...
I can only hear what I can hear. Even if you can reproduce a signal with harmonic or transient energy above the upper limit of my ear's frequency response, I won't hear it. If you could compare the waveform produced by the act of hearing with the waveform direct from the hifi system, they would be different, filtering would have smoothed out the higher harmonics, erased the transients. This applies to intermodular distortions too, it applies to everything in the frequency domain because there is no mechanism for discrimination.
I am happy that my nCores are more capable than my ears.
Well I believe that the "ultra tweeter" was brought up by StigErik to prove the kind of insanity that super audio discussions can result in. Am i right there StigErik?
Not to bring up more mud in the discussion, but I believe that the "ultra tweeter" is meant not to reproduce signal at 1 GHz but to beam out ultrasonic energy (very short wave lengths) to condition the propagation of the audio signal from the existing speaker. This is a rather well known method which is typically used to focus the directivity (and thus carry) a signal of much longer wave lengths both in audio and in energized particles such as light beams.
The point is that the "ultra tweeter" is designed to condition the directivity and propagation of the audio signal, not extend its bandwidth and HF content per se.
Mixing this principle with the other discussion on whether or not audio signal reproduction above human hearing has any relevance is like mixing apples and pears. Lets keep it straight.
Julf, we might agree to disagree (and i do respect your position), but I believe that where we see things differently is not whether or not we need "evidence" for a claim, but what kind of observations that we value. To me listening is still the ultimate reference regarding designing and evaluating audio equipment where measurements are important too, but they are still subject for interpretation just as listening is. This is not to say that I am "more right", but to point out preferences regarding how we use observations to form questions and answers.
best
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