07-01-2013 11:06 AM - edited 07-01-2013 12:31 PM
In music and sound timbre/character we speak of two categories of sounds:
- Harmonious, i.e. grand piano
- Non-harmonious, i.e. gong, thunder sheet
Drums are usually categorized as non-harmonious, but a timpani sound is harmonius, as well a snare drum is harmonious when the snares are off.
07-01-2013 06:04 PM
07-01-2013 06:05 PM
07-01-2013 06:09 PM
Odd harmonics (from tape saturation for example), give a sense of prescence, they cut through the mix(good on vocals), even (from tubes for example) a sense of peach fuzz or softness, sounds old and warm.
07-03-2013 03:38 AM - edited 07-03-2013 03:41 AM
Fundamentals, Harmonics, and Overtones
In acoustics the basic vibration is the 'first harmonic'.
The term overtone is used to refer to any resonant frequency above the fundamental frequency. The 'second harmonic' (twice the fundamental frequency) is the first overtone. Persons who count differently are wrong.
There are integer multiples of a certain frequency (fundamental), that are called harmonics, partial tones (partials) or overtones. It is important to note that the term 'overtones' does not include the fundamental frequency.
The first overtone is therefore already the second harmonic or the second partial. The term overtone should never be mixed with the other terms, as the counting is unequal.
The term harmonic has a precise meaning - that of an integer (whole number) multiple of the fundamental frequency of a vibrating object. A harmonic frequency is a multiple of a fundamental frequency, also called "harmonic". When it comes to counting, do not say: "overtones are harmonics".
Musicians prefer the term overtones and physicists prefer the harmonic term.
Sound engineers are somewhat uncertain between these two terms. Harmonics and overtones are also called resonant frequencies.
The sound spectra of clarinets tend to have strong odd harmonics (fundamental, 3rd, 5th, 7th etc) and weak even harmonics (2nd, 4th, 6th etc), at least in their lowest registers.
Overtones whose frequency is not an integer multiple of the fundamental are called inharmonic and are often perceived as unpleasant. Enharmonics (inharmonics) that are not close to harmonics are known as partials. Bells have more clearly perceptible partials than most instruments.
An "exciter" is a special equalizer, which creates new overtones. The processed signal is added to the original input signal.
Typical "warm" tube sound, particularly triodes contain predominantly in the spectrum:
- even-numbered multiples of the fundamental frequency, and thus outstanding
- even-numbered harmonics, or even-numbered partial tones 2, 4, 6…
One can also say, tube amplifiers at high levels (distortion) contain strong odd-numbered overtones - that are even-numbered partials or harmonics.
Standing waves (acoustic resonance) on ideal strings. Standing waves are stationary waves. A standing wave is the vibration state of a coherent system. As an example for this usually the vibrating string of a musical instrument or the column of air in an organ pipe is taken. These waves have a wave-like look, but nothing is moving. The string is clamped with a length L between two fixed ends, which is always a node (zero crossing). Between two nodes is always an antinode.
© Eberhard Sengpiel, professor for engineering and recording technology at UDK Berlin. Grammy Award winning recording engineer, i.e. with the Chicago Symphony Orchestra.
07-03-2013 08:25 AM
in this graph you can see the highest violin open E string (bowed) has less dense harmonics then the lowest G string, the partial are further apart, therefor sounds thinner
07-05-2013 11:38 AM
Well, reading wikipedia, evidently there's no consistent numbering scheme. The article on "Harmonic" reads as others cite above, whereas the article on "waveform" uses my numbering scheme.
If we use the word "overtone", it's unambiguous (my counting).
PS: The Harmonic article seems to contradict itself in its first sentence:A harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency, i.e. if the fundamental frequency is f, the harmonics have frequencies 2f, 3f, 4f, . . . etc.Evidently, there is no such thing as a "first harmonic". Silly definition, if you ask me, though perhaps they did it to avoid a "minus one" when doing the math.
The trouble is that most guitar players haven't even taken a elementary theory class.
Harmonics and Overtones refer to all frequencies *above* the fundamental, and Partials include the fundamental along with the harmonics/overtones. The definition you quoted is technically correct
07-05-2013 01:00 PM
Rudolf von Hagenwil wrote:
For example the partials of a timpani are:
When you stack a chord in the string section with this frequencies, then it sound somewhat like a timpani.
There is no musical instrument which has exactly this partials as often seen in music harmony books,
this is theory, a mathematical ideal for educational purpose. When you artificially generate this sound above it sounds total boring. In other words the frequencies of the partials are at different pitched for each musical instrument.
If you assigned the frequencies for a Tympani to a string section, it will not sound like a tympani for at least two reasons.
1. Each string has it's own harmonics.
2. As someone above alluded to, each partial has it's own amplitude envelope, which would need to be duplicated by any instruments attempting to synthesize a timpani's timbre.
What is needed is an additive synthesizer that allows the frequency and amplitude envelope to be specified for each partial.
And tympani are more the exception than the rule for orchestral instruments (well, excluding the percussion family). Most instruments *do* have partials from the standard overtone series. A particular instrument may not have *all*, and certainly each instrument will have different envelopes from other instruments.
07-05-2013 01:42 PM
I love how, in the piano version of Moussorgsky's "The Great Gate of Kiev", he has you pounding out these strange fistfulls of notes in the bass keys... yet played, they sound just like a huge church bell... ie., he was able to suss out the individual frequencies that comprise the big discordant clap of a huge bell.
07-05-2013 01:43 PM
>>> In the case of real world musical instruments, the partials don't all emerge from the same point on the instrument, so the fact that there's a fixed time displacement addsl to the amount of phase shift from the fundamental. You'll get a different complex waveform if the second harmonic starts at the same time as the fundamental than if the second harmonic starts at a different time.
All of this goes into what makes a violin sound different from a trumpet when they play the same (fundamental) note.
Very well stated; good post!
Most of what distinguishes a violin from anther instrument is mainly the partial series and their amplitude envelopes. Phase variations are minor.
07-05-2013 01:47 PM
Rudolf von Hagenwil wrote:
Fundamentals, Harmonics, and Overtones
"In acoustics the basic vibration is the 'first harmonic'.
The term overtone is used to refer to any resonant frequency above the fundamental frequency. The 'second harmonic' (twice the fundamental frequency) is the first overtone. Persons who count differently are wrong."
I disagree. Every book that I've read specifies that Partials include the fundamental, but Harmonics and Overtones do not.
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