Why is it that the fundamental harmonic is louder than rest?

In summary, the conversation discusses the relationship between frequency, energy, and amplitude in waves. It is clarified that energy and frequency are related in Quantum Mechanics, but in classical waves, both energy and amplitude play a role in determining the total energy. The concept of power and conservation of energy is also introduced in the context of refraction. Ultimately, it is emphasized that the understanding of these concepts depends on the specific context and cannot be generalized in all cases.
  • #1
Theudius
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Why is it that the fundamental harmonic is louder than rest? If energy is the same as frequency surely the greater the harmonic the louder it is.

Also what does amplitude represent in waves?
 
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  • #2
Theudius said:
If energy is the same as frequency
It's not.

Theudius said:
Also what does amplitude represent in waves?
The maximum distance between peaks and troughs, measured parallel to the direction of oscillation.
 
  • #3
And the fundamental does not have to be the loudest. You can excite the system such that the higher harmonics have larger amplitudes. Even with zero amplitude for the fundamental.
However the damping usually increases with frequency and after some time after the excitation, the higher harmonics die faster and the fundamental may dominate.
 
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  • #4
Theudius said:
Why is it that the fundamental harmonic is louder than rest?

Your question prompted me to do some reading and it turns out that it's not always the case e.g. for some musical instruments such as the trumpet the higher harmonics have a larger amplitude.
 
  • #5
I think that the fundamental is called that because it's the one you hear. If there are lower frequencies present and they are lower amplitude than the fundamental, they are called sub-harmonics. The amplitude is representative of the loudness, although loudness is a psychological phenomena in some cases.
 
  • #6
The term fundamental has nothing to do with loudness. It is the lowest frequency mode of the system. The sub harmonics have lower frequencies. Amplitudes are not relevant for these definition.
 
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  • #7
cosmik debris said:
I think that the fundamental is called that because it's the one you hear.
It's not always. However, the overtones of any standing wave are usually the highest amplitude. The way the oscillations are matched to the air can bring out higher order overtones out more. I use the term Overtone because the higher orders may be far from harmonics. Brass instruments can be waaay out without the player pulling notes. But it's what we find pleasing.
 
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  • #8
I was told by my physics lecturer energy is the same as frequency, if this is not the case what is energy represented by in a wave?
 
  • #9
Theudius said:
I was told by my physics lecturer energy is the same as frequency, if this is not the case what is energy represented by in a wave?

What he was referring to was Quantum Mechanics. In particular, the formula
E = hf tells you the energy of a photon.
 
  • #10
Theudius said:
I was told by my physics lecturer energy is the same as frequency, if this is not the case what is energy represented by in a wave?

As sophiecentaur points out, the energy of a photon is proportional to the frequency of the light. The number of such photons determines the total energy at that frequency.
 
  • #11
Theudius said:
Why is it that the fundamental harmonic is louder than rest? If energy is the same as frequency surely the greater the harmonic the louder it is.

Also what does amplitude represent in waves?
what kind of system are you referring to?
 
  • #12
Theudius said:
I was told by my physics lecturer energy is the same as frequency, if this is not the case what is energy represented by in a wave?

You need context. While energy can be related to energy, it is NOT the ONLY factor when considering the energy of a classical wave. The amplitude of the wave also affects the energy. So your physics lecturer is correct. However, you understood it as it being the only factor affecting energy.

Zz.
 
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  • #13
He used it to explain how wavelength and wave speed change yet the frequency stays the same when light enters a medium. He stated frequency is energy and energy is conserved.
 
  • #14
Theudius said:
He used it to explain how wavelength and wave speed change yet the frequency stays the same when light enters a medium. He stated frequency is energy and energy is conserved.

Actually, what is conserved is "power", the amount of energy going through a point in a unit time. It is why, for a light source with a fixed power, increasing the frequency will cause the intensity to drop, because there can only be a fixed amount of energy given off per second.

So while this is true in the case of refraction, you need to be clear that this is the case where there is a fixed amount of energy being given to start with. It is not true in ALL general cases. This is easy to see if you have 2 different spring-mass systems. Use the same mass, but use different spring constant k. Now let them oscillate with the same amplitude. Which one do you think will have more "energy"? Next, change the amplitude of each one of them. Do you think each one will have the same energy as before if I oscillate them with a different amplitude? After all, the frequency of oscillation for each one of them remains the same as before.

When you ask a question in this forum, it is imperative that you be very clear and concise. If it is related to something, or it is something you're thinking of in your head, don't assume that (i) we can read your mind and (ii) you have a general "rule" that will be true everywhere. When you are asking about something with a particular context in mind, you must reveal that context. Otherwise, we will be talking about chickens while you're thinking about cows.

Zz.
 
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1. Why is the fundamental harmonic louder than the rest?

The fundamental harmonic is louder because it has the lowest frequency and the largest amplitude compared to the higher order harmonics. This means it produces a stronger sound wave that is more easily detected by our ears.

2. What is the relationship between frequency and loudness in regards to the fundamental harmonic?

The frequency of a sound wave determines its pitch, while the amplitude determines its loudness. The fundamental harmonic has a lower frequency and higher amplitude, which makes it both lower in pitch and louder in volume compared to higher order harmonics.

3. Can the loudness of the fundamental harmonic be changed?

Yes, the loudness of the fundamental harmonic can be changed by altering the amplitude or strength of the sound wave. This can be done through adjusting the volume or using techniques such as equalization to boost specific frequencies.

4. How does the loudness of the fundamental harmonic affect the overall sound of an instrument?

The loudness of the fundamental harmonic plays a significant role in the overall sound of an instrument. It is the dominant frequency that gives an instrument its unique tone and character. A stronger fundamental harmonic will result in a more powerful and distinct sound.

5. Is the loudness of the fundamental harmonic the same for all instruments?

No, the loudness of the fundamental harmonic can vary depending on the type of instrument and the way it is played. For example, string instruments tend to have a stronger fundamental harmonic than wind instruments, and the technique of the musician can also affect the loudness of the fundamental harmonic.

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