I think you have to take it as one data point. Or disregard it. I suspect I could never persuade you.
But why not try see if you hear above 20k.. play 24k and at the same time do a RTA analysis of the content coming out of the transducer to secure that it is only 24k and nothing else... and you can detect it. Make someone else flip the switches... But if you see sidebands (above and or below - below of course most interesting here) you need to rethink your tets setup...
Good luck!
//
But why not try see if you hear above 20k.. play 24k and at the same time do a RTA analysis of the content coming out of the transducer to secure that it is only 24k and nothing else... and you can detect it. Make someone else flip the switches... But if you see sidebands (above and or below - below of course most interesting here) you need to rethink your tets setup...
Good luck!
//
Can you prove that? What kind of source was emitting this frequency?
I would like to read those studies! What is the exclusiveness of 'those' people?
Maybe you have access to studies posted in #39?
This is a distinction without a difference. It is an intermodulation product and it is measured in Hz. It is a frequency. Period.
Otherwise please explain superheterodyning without recourse to the word ‘frequency’. And then explain why the result is called an intermediate frequency.
False. Please read the wiki, its been posted enough times already. https://en.wikipedia.org/wiki/Beat_(acoustics) If you don't understand it then you should probably ask questions rather than keep repeating a false claim.
To recap, intermodulation in a nonlinear process that produces new frequencies called sidebands. The new frequencies will show up on an FFT.
Beat notes are produced by a linear process, so no new frequencies are produced. The effect is a volume envelope that does not show up as a new frequency in an FFT. It takes the use of a Hilbert transform to show the volume envelope waveform. That said, a beat note can sometimes be perceived as a frequency by the human auditory system (as explained in the wiki).
Exactly, and that is why the mixer in a superheterodyne receiver is essentially a multiplier and not an adder. Even a so-called additive mixing stage is a primitive multiplier: you add two signals and pass them through something with even-order non-linearity, so you get their product and a whole lot of other stuff you don't want.
It was in a psychology class at university.
You'll find studies that back me up if you google.
I can't find it. Can you drop it here? You know the sources.
'Psychology class'... ???
Does psychology classes emit frequencies of 20kHz & above?
At universities?
Without stimuli?
I'm baffled.
"Under ideal laboratory conditions, humans can hear sound as low as 12 Hz ...and as high as 28 kHz..."
See link to reference #9 at:
https://en.wikipedia.org/wiki/Hearing_range#:~:text=The human range is commonly,shown by equal-loudness contours.
See link to reference #9 at:
https://en.wikipedia.org/wiki/Hearing_range#:~:text=The human range is commonly,shown by equal-loudness contours.
Whatever you do, don't take a bath in liquid helium ( https://www.diyaudio.com/community/...on-range-its-not-20-20khz.424670/post-7946516 ).
With 25 years of age I travelled with the Philips bus to my work.
There was a smps on board feeding the high voltage fluorescent tubes.
The screaming high frequency sound did hurt my ears, but I was the only one of all people in the bus, so it may have been above 20kHz.
Now I’m happy to hear up to 15kHz.
Do I enjoy less when listening to music, no not at all.
IMO all these super high frequencies do add very little to your sound perception if any at all, it’s highly overestimated.
Hans
There was a smps on board feeding the high voltage fluorescent tubes.
The screaming high frequency sound did hurt my ears, but I was the only one of all people in the bus, so it may have been above 20kHz.
Now I’m happy to hear up to 15kHz.
Do I enjoy less when listening to music, no not at all.
IMO all these super high frequencies do add very little to your sound perception if any at all, it’s highly overestimated.
Hans
If memory serves me correctly ...
The vast majority people who could hear above 20Khz were young woman.
It's hard enough to reproduce 20-20khz. Ain't got no time to worry about anything outside of that.
2 cents ...
It isn't actually hard to produce frequencies from 20-20khz > BUT, to produce it with linearity & low distortion is another story 🙂
PS.
Because people now have far greater accessibility to measurements with MIC / SOFTWARE ,
I want to now see a lot more of 'speaker square wave performance' at a number of 'spot frequencies'.
Square waves contain a lot of information.
Of course, the driving amplifier MUST be up to the task.
Because people now have far greater accessibility to measurements with MIC / SOFTWARE ,
I want to now see a lot more of 'speaker square wave performance' at a number of 'spot frequencies'.
Square waves contain a lot of information.
Of course, the driving amplifier MUST be up to the task.
