Aloha,
I got a topic that's been buzzin' round in my head longer than DUP's hatred of Chord amps - harmonics, overtones, and sound reproduction.
The set up:
When you create a sound, what gets propagated and what we hear is more than just the sound that the instrument made.
We are taught that a sound at a given frequency creates more sounds at frequencies that are multiples of the frequency of the first sound, and overtones get created that may actually differ from instrument to instrument.
So, a 100Hz tone would generate "fundamental" harmonics at 200, 400, 800, 1600, and so-on Hz.
The order for harmonics is that the actual tone is the first harmonic, and the second harmonic becomes the first overtone.
So, what makes it to the microphone is more than what you'd think was the original tone, and is one reason people think that sound reproduction above 20,000Hz may be important...
Overtones are kind of like harmonics that do not occur at such evenly distributed frequencies.
To quote Wikipedia: "Not all overtones are necessarily harmonics, or exact multiples of the fundamental frequency. Some musical instruments produce overtones that are sharper or flatter than harmonics. The sharpness or flatness of their overtones is one of the elements that contributes to their sound; this also has the effect of making their waveforms not perfectly periodic."
OK, now comes the hi-fi conundrum for me:
When we take what had been the original sound heard by the microphone during the recording and try to recreate that event on our home systems, we start creating harmonics of harmonics and harmonics of overtones that were never intended to be part of the sound.
Your speaker reproduces the original signal, but is also responsible for creating extra harmonics of the original harmonics and overtones that never existed!
(Say you have a flute note that created an original note a 400Hz. You'd have harmonics at 800, 1600, 3200, 6400, 12,800Hz; and overtones at odd intervals depending on the note or how hard the note was blown. Hypothetically, say 430Hz for just one of the overtones.
OK, now you want your speakers to create this melange of sounds, but when your speaker creates those tones, you create more harmonics and overtones!
So, that hypothetical 430Hx overtone now creates harmonics at the typical ratio of tone to harmonics, and those sounds were NEVER part of the original sound.)
Your speaker doesn't know that they were just harmonics, and now you get harmonics of harmonics!
No matter how good your system is, all it will ever do is create falsely exaggerated harmonic textures and add harmonics of overtones that are totally artifactual.
In theory, there is no way to ever faithfully recreate the sound of the original performance.
It seems to me that we must be listening to way too many harmonics.
What a drag!
How the heck can reproduced sound ever sound right when it will never be able to actually reproduce just the sounds that the microphone heard?
_____________________
On a related note, does electronic gear create harmonics of the frequencies of the sounds it passes? I've heard answers both ways.
Like, does a preamp create harmonics of the tones that go through it?
You'd think after a few trips through the chain, all we would get is a big harmonic smear.
Is it happy hour yet?
Aloha,
I got a topic that's been buzzin' round in my head longer than DUP's hatred of Chord amps - harmonics, overtones, and sound reproduction.
The set up:
When you create a sound, what gets propagated and what we hear is more than just the sound that the instrument made.
We are taught that a sound at a given frequency creates more sounds at frequencies that are multiples of the frequency of the first sound, and overtones get created that may actually differ from instrument to instrument.
So, a 100Hz tone would generate "fundamental" harmonics at 200, 400, 800, 1600, and so-on Hz.
The order for harmonics is that the actual tone is the first harmonic, and the second harmonic becomes the first overtone.
So, what makes it to the microphone is more than what you'd think was the original tone, and is one reason people think that sound reproduction above 20,000Hz may be important...
Overtones are kind of like harmonics that do not occur at such evenly distributed frequencies.
To quote Wikipedia: "Not all overtones are necessarily harmonics, or exact multiples of the fundamental frequency. Some musical instruments produce overtones that are sharper or flatter than harmonics. The sharpness or flatness of their overtones is one of the elements that contributes to their sound; this also has the effect of making their waveforms not perfectly periodic."
OK, now comes the hi-fi conundrum for me:
When we take what had been the original sound heard by the microphone during the recording and try to recreate that event on our home systems, we start creating harmonics of harmonics and harmonics of overtones that were never intended to be part of the sound.
Your speaker reproduces the original signal, but is also responsible for creating extra harmonics of the original harmonics and overtones that never existed!
(Say you have a flute note that created an original note a 400Hz. You'd have harmonics at 800, 1600, 3200, 6400, 12,800Hz; and overtones at odd intervals depending on the note or how hard the note was blown. Hypothetically, say 430Hz for just one of the overtones.
OK, now you want your speakers to create this melange of sounds, but when your speaker creates those tones, you create more harmonics and overtones!
So, that hypothetical 430Hx overtone now creates harmonics at the typical ratio of tone to harmonics, and those sounds were NEVER part of the original sound.)
Your speaker doesn't know that they were just harmonics, and now you get harmonics of harmonics!
No matter how good your system is, all it will ever do is create falsely exaggerated harmonic textures and add harmonics of overtones that are totally artifactual.
In theory, there is no way to ever faithfully recreate the sound of the original performance.
It seems to me that we must be listening to way too many harmonics.
What a drag!
How the heck can reproduced sound ever sound right when it will never be able to actually reproduce just the sounds that the microphone heard?
_____________________
On a related note, does electronic gear create harmonics of the frequencies of the sounds it passes? I've heard answers both ways.
Like, does a preamp create harmonics of the tones that go through it?
You'd think after a few trips through the chain, all we would get is a big harmonic smear.
Is it happy hour yet?