I think I am not advanced as you are . . .
The speakers do piston work . . . within the distance of 2*amplitude . . . (of the music signal)
I do not see any different distances and directions of the piston work between the non-inverting and the inverting, if I think about them with a very short time lag . . . I must be missing your knowledge . . .
The speakers do piston work . . . within the distance of 2*amplitude . . . (of the music signal)
I do not see any different distances and directions of the piston work between the non-inverting and the inverting, if I think about them with a very short time lag . . . I must be missing your knowledge . . .
Non-periodic variations in the air pressure correspond to noise, whereas oscillations at frequencies in the ratios of simple integers are recognized as musical tones.
The pitch of a musical tone is the lowest (fundamental) frequency. The quality (of oboe, trumpet . . . ) which ears can distiguish is a measure of the relative amplitudes of the overtones, most often harmonics, excited simultaneously with the fundamental oscillation . . .
When a guitar player plays music, do we see any asymmetric string vibrations on the neutral axis . . . ?
The pitch of a musical tone is the lowest (fundamental) frequency. The quality (of oboe, trumpet . . . ) which ears can distiguish is a measure of the relative amplitudes of the overtones, most often harmonics, excited simultaneously with the fundamental oscillation . . .
When a guitar player plays music, do we see any asymmetric string vibrations on the neutral axis . . . ?
Not necessarily. The whole signal chain from source to sink is lossy. If we now make the transmission path significantly better than the sink (the human) we have a close to lossless situation.
Unfortunatley we are far from it - though modern digital media is at least close at least on the storage side. But CD is definitely insufficient
Of course !
Regards
Charles
You are oversimplifying things. Oscillations in music are time varying, thus non-periodic even in very short time window.
Question: What do you get when you sum sinewave and its first harmonic overtone?
Answer: Asymmetric waveform.
Question: What do you get when you change polarity of this waveform?
Answer: Different waveform.
Question: Is there audible difference between these waveforms?
Answer: I don't know. It depends on operation mechanisms of human ears, nerves and brain. I don't know those very well because i'm also just an engineer.
Ja . . . I m a simple man, thinking simple.
The fundamental "frequency" is periodic.
The speakers do piston work accordingly . . .
On it, the 1st overtone "f" is also periodic.
The speakers do piston work accordingly
upon the fundamental "f" piston work . . .
On it, the next overtone "f" is again also periodic.
The speakers do piston work accordingly
upon the fundamental plus the 1st overtone "f" piston work . . .
.
.
.
Overall, the speakers piston work looks terrible and starnge . . . Let's take a video record and play back with slow motion . . .
The fundamental "frequency" is periodic.
The speakers do piston work accordingly . . .
On it, the 1st overtone "f" is also periodic.
The speakers do piston work accordingly
upon the fundamental "f" piston work . . .
On it, the next overtone "f" is again also periodic.
The speakers do piston work accordingly
upon the fundamental plus the 1st overtone "f" piston work . . .
.
.
.
Overall, the speakers piston work looks terrible and starnge . . . Let's take a video record and play back with slow motion . . .
Simple thinking is good. Things should be thought as simple as possible, but not any simplier than that.
Periodic signal consists as you said of fundamental frequency and harmonic overtones. You only need to know relative amplitude and relative phase of each overtone to describe the whole signal. When polarity of signal is changed relative amplitudes stay same as before, but relative phases of even multiples of fundamental frequency are changed 180 degrees (relative to phase of fundamental). It's not only question of starting point of signal in timeline, you actually need different coefficients for overtones to describe signal that has inverted polarity.
Periodic signal consists as you said of fundamental frequency and harmonic overtones. You only need to know relative amplitude and relative phase of each overtone to describe the whole signal. When polarity of signal is changed relative amplitudes stay same as before, but relative phases of even multiples of fundamental frequency are changed 180 degrees (relative to phase of fundamental). It's not only question of starting point of signal in timeline, you actually need different coefficients for overtones to describe signal that has inverted polarity.
Yes. The whole signal is flipped 180 degrees relative to fundamental frequency F.
Relative to F*2 that is 360 degrees and 360-180=180.
Relative to F*3 that is 540 degrees and 540-180=360 which is same as 0 degrees for periodic signal.
Relative to F*4 that is 720 and 720-180 is 540 which is same as 180 degrees for periodic signal, and so on...
Every even multiple of fundamental frequency has 180 degrees phase change relative to fundamental.
Relative to F*2 that is 360 degrees and 360-180=180.
Relative to F*3 that is 540 degrees and 540-180=360 which is same as 0 degrees for periodic signal.
Relative to F*4 that is 720 and 720-180 is 540 which is same as 180 degrees for periodic signal, and so on...
Every even multiple of fundamental frequency has 180 degrees phase change relative to fundamental.
komen said:
If that was the case, then a square wave would look different if it was inverted!
If you invert a signal, every harmonic has the same relationship to the fundamental as it had when it was non-inverted.
Absolute phase may be identifiable in certain circumstances, but it's got nothing the do with the phase relationship of the harmonics of the signal.
I found fine text about asymmetric waves. Read this and we can end discussing about existence of asymmetric waves.
http://www.st-and.demon.co.uk/AudioMisc/asymmetry/asym.html
http://www.st-and.demon.co.uk/AudioMisc/asymmetry/asym.html
komen said:
Ah . . . yes . . .
Trumpet shows the asymmetric wave.
They are a sum of their harmonic components.
Say, 6 harmonic components, for example . . .
There are 6 harmonic components of sinusoidal and flip them all . . . And mix them again . . .
Now what shape we see . . . ?
At least me, see the same wave.
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