if someone is able to hear a 20khz sine wave he can hear the base tone (1st harmonic) of the 20k square wave too!
But I was told the following: in this case we can't hear the upper harmonics!! so it can be quite dangerous for damaging your ears listening to square waves at high volume!! you don't hear but it might damage your ears!! don't know whether this is right or not, and I'm not going to try it out.
best regards,
HB.
But I was told the following: in this case we can't hear the upper harmonics!! so it can be quite dangerous for damaging your ears listening to square waves at high volume!! you don't hear but it might damage your ears!! don't know whether this is right or not, and I'm not going to try it out.
best regards,
HB.
It is more complicated than this. In fact, someone could make a sine-square comparison at 20KHz or even 10KHz, and 'prove' that it is inaudible.
Still, I made a test about 20 years ago with three people. I used a Pioneer ribbon tweeter with a measured response of more than 45KHz, with an Electrocompaniet, Otala based power amp, and a function generator. As I remember, I set the function generator with a 5KHz square wave and deliberately limited the risetime to 3.5us, which is about a 100K response, with a quality film polystyrene cap to ground. The function generator had a buffered 50 ohm output. Then, during the test, I added another polystyrene cap in parallel to ground to change the effective risetime to 10us, or 35KHz. We all could hear the difference. It was fairly easy to, as well. Why? I don't know, but we seem to be sensitive to rate-of-change, more than actual frequency response.
Still, I made a test about 20 years ago with three people. I used a Pioneer ribbon tweeter with a measured response of more than 45KHz, with an Electrocompaniet, Otala based power amp, and a function generator. As I remember, I set the function generator with a 5KHz square wave and deliberately limited the risetime to 3.5us, which is about a 100K response, with a quality film polystyrene cap to ground. The function generator had a buffered 50 ohm output. Then, during the test, I added another polystyrene cap in parallel to ground to change the effective risetime to 10us, or 35KHz. We all could hear the difference. It was fairly easy to, as well. Why? I don't know, but we seem to be sensitive to rate-of-change, more than actual frequency response.
Did you do careful measurements of the output of the driving amp and the ribbon to see if you were changing anything else unexpectedly? If I were running a test like that and differences were "easy" to hear, I'd suspect that there was a variable that I hadn't controlled for- like a small level change. Certainly the addition of the cap will do some change to the relative levels of the fundamental and the 3rd harmonic (at 15K, still within the range of normal ears).
PMA said:
Yes. But perception is not always an accurate reflection of the physical reality, something which has been demonstrated for nearly 100 years now. And until that aspect is ruled out, there will always be some ambiguity when it comes to etablishing the actual cause of a given effect.
se
john curl said:There isn't any answer that will satisfy SE, we have debated at this level for years. I did the best that I could to keep everything in check, BUT there are always tiny differences. You know, the ones that we probably don't hear anyway?
You know that's not true, John.
Just because I don't unquestioningly swallow everything that comes down the pike doesn't mean that no answer will satisfy me. It's just that as long as reasonable ambiguities remain, I'll continue to question.
se
pinkmouse said:There is also the fact that about 75% of people over the age of 25 can't actually hear above about 15K. Also due to the world around generally being a noiser place, and the proliferation of young people listening to loud music, that age will get lower and lower
Them why castles find dirt glory since in doorway fleece get for from dinner each lollypop? Say what?
se
I´m not so sure about this anymore.
Here some interesting related reading:
On the Threshold of Discovery
There's Life Above 20 Kilohertz!
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