Questions tagged [harmonics]
222 questions
166
votes
4 answers
Why are the harmonics of a piano tone not multiples of the base frequency?
I was trying to figure out which piano keys were being played in an audio recording using spectral analysis, and I noticed that the harmonics are not integer multiple of the base note. What is the reason for this?
Take a look at the spectrogram of…
Szabolcs
- 1,533
32
votes
7 answers
Why do higher harmonics have a lower amplitude than the fundamental frequency?
When we pluck a string, it vibrates in all possible modes of vibrations. The lowest frequency possible is the fundamental frequency and it is the most significant part of sound.
But why do the amplitude of higher harmonics decrease? Which formula is…
Rahul R
- 1,037
23
votes
5 answers
Why do harmonics occur when you pluck a string?
When you energise a taut string, the following resonant modes of vibration occur:
Plotting on the frequency domain, you can see their corresponding frequencies:
But what is the underlying physical principle? Why does this happen?
Is there any way…
P i
- 341
20
votes
4 answers
How are overtones produced by plucking a string?
I read the following from wikipedia:
When a string is plucked normally, the ear tends to hear the
fundamental frequency most prominently, but the overall sound is also
colored by the presence of various overtones (frequencies greater than
the…
Display Name
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13
votes
3 answers
Pressure standing wave nodes at the end of the open side of a tube
I do not understand why standing sound waves can be formed in a one-side or two-side open tube. Consider a one-side open tube.
In particular how does the reflection of the wave at the open end occur? I found the following explanation.
The sound…
Sørën
- 2,727
11
votes
9 answers
Feynman claimed "The ear is not very sensitive to the relative phases of the harmonics." Is that true?
In The Feynman Lectures on Physics, Dr. Richard Feynman claimed that the ear (I assume he meant the human ear) is not sensitive to the relative phases of harmonics.
However, I was asked to test electronic filters with a Textronix Vista tester using…
Dan Bullard
- 149
10
votes
3 answers
Why is the energy of the harmonics in a vibrating string not infinitesimal?
When you pluck a guitar string, initially the vibration is chaotic and complex, but the components of the vibration that aren't eigenmodes die out over time due destructive interference. This ostensibly explains why the harmonics quickly become…
silver
- 227
10
votes
5 answers
If all harmonics are generated by plucking, how does a guitar string produce a pure frequency sound?
A guitar is a plucked instrument and it is played by plucking a string at an off-centre point fixed at two ends. In general, Fourier analysis tells that all harmonics (the resonant frequencies of the string) will be excited and the string will…
Solidification
- 12,736
10
votes
2 answers
How can you make harmonics on a string?
For an oscillating string that is clamped at both ends (I am thinking of a guitar string specifically) there will be a standing wave with specific nodes and anti-nodes at defined $x$ positions.
I understand and can work through the maths to obtain…
loolipop
- 203
10
votes
3 answers
Need mathematical explanation for different musical notes sound different on different instruments
I am not expert in music.
There are number of musical instruments. One (especially a person who knows about music) can blindly recognize which instrument is being played just by listening to it.
I need mathematical explanation about…
devraj
- 231
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9
votes
4 answers
Using $\sin()$ or $\cos()$ for computing SHM?
In simple harmonic motion, you can use either the sin or cos form of the equation but my question is which one do you use when and why?
I am having a tough time understanding this, so any help would be thoroughly appreciated
user34304
- 1,843
9
votes
3 answers
What is fundamental frequency, how does it make sense?
I’m currently going through harmonics, and I do not at all understand the fundamental frequency. I understand that it is the simplest vibration of a string, but I don't understand how can it have frequency at all if it is only half a wavelength.…
9
votes
1 answer
Fractional harmonics in musical Instruments
I recently did some Fourier transforms on different audio files containing saxophone or trumpet (John Coltrane/Clifford Brown).
I found that with the saxophone, the frequency spectrum occasionally contained half-integer and even quarter-integer…
soultrane
- 201
8
votes
2 answers
Why coupled oscillators tend to seek integer frequency ratios?
In this document, the author writes (page 225)
Coupled oscillators have a tendency to seek frequency ratios which can be expressed
as rational numbers with small numerators and denominators. For example,
Mercury rotates on its axis exactly…
Ma Joad
- 1,425
8
votes
3 answers
Why are the closed and open ends of an organ pipe nodes and anti-nodes?
Here is a diagram of a wave in an organ pipe you'll find in most physics books
Waves in air are longitudinal (not traversal), so what do the curves represent?
Why are the open ends always anti nodes and the closed ends always nodes?
dark32
- 195