Can someone explain how rolling on/off tone changes sound of a note. How can a note change?

bananasushi

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I have used the tone knobs and I know what they do, give it some more bass or roll it off. But every note vibrates at a certain frequency. An 'A' is an 'A'. When you turn the tone knob and add more bass, is it still considered an 'A'? or is it like a pitch shift. How can an A be modified when it has its own frequency of say 440Hz. I mean to me, speaking in terms of a piano, all the keys are in a spectrum going from bass, to alto, to treble etc. I know all note to the right become higher or more trebley and to the left become more bassey. I guess there is no exact line you cross where you are not in bass anymore and now it treble. Anyways to me going more bass, means going down the SCALE using DIFFERENT notes to the left with a different wavelength. If an A vibrates at a certain pitch and you roll the tone knob adding or removing bass/treble how is it still an A? Is it still an A? Or is it moving the note down a half step or something? I'm just confused at what is going on here. I don't even know if I'm making any sense. It's hard to explain.
Or... does every note contain characteristics of lows mids and highs? That's the only thing I can think of. But aren't lows mids and highs also different frequencies? So if an A resonates at the assigned 440Hz, that is the frequency isn't it? A bass note would have a different frequency. How can a note contain multiple frequencies.
I know a perfect midi tone sounds terrible. It's perfect but all analogue instruments are imperfect yet sound way more beautiful than a midi.
Or is this a case of improper words being used? Like how people call a whammy bar, aka, vibrato tailpiece a tremelo arm, which it isn't tremolo. That is an actual case of the frequency of the note changing.
 

Blue Bill

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I'll try: Imagine the same note played by a saxophone and also played by a guitar. They're the same note, yes, the same frequency, yet they sound quite different, easy to tell apart. The difference is in extra vibrations, things like harmonics, distortions, reverb, phase phenomena, etc., what #Vibroluxer called timbre. The treble control will lessen the extra things that vibrate at higher frequencies and harmonics, letting the fundamental note and lower frequency components sound out.
 

telemnemonics

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Many words used to describe physical things are not really scientific.

For example the 12 tone scale is tones which based on language representing physics, proves that words fail here.

Do you want a scientific explanation of why an oboe does mot sound like a guitar?
That explanation requires those pesky words.

Otherwise, no, the frequency of the note does not change.
Note though that "a note" does indeed contain far more than one frequency.
That is why each note we hear, a note that is sounding, has what is called "the fundamental" plus harmonic content.
 

24 track

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really it gets back to the theory ,I guess for lack of another word , of the principles of EQing , basically the tone rolls off the top end as the signal in blended to ground through the capacitor which acts like filter .
in an EQ circuit there is a targeted frequency that you can add or subtract +/- 0/6/12 db gain as an example but the curve it creates is called a Q while some graphic EQs use a fixed Q , a parametric will give you a veriable Q.

by taking that verible Q and sweeping it up and down the full extent of the frequency range gives you a wha effect and is the engine for alot of wha/wha pedals , and why some plyers wil use a wha as a tone control .

when you use the onboard tone control you are not changing the pitch of the note but infact changing or controlling the amout of tonal filtering to ground through the capacitor , so answer your question the tone does not affect the pitch so an A-440 will still Be an A-440 but frequency filtered ,

this can be seen an a 31 band 1/3rd octave graphic EQ , its called a 3rd octave because every 3 bands of the EQ will double the frequency affected ,for example a 200hz range is doubled to 400hz range with 3 steps in between and again at 800hz with 3 steps in between so on where each step is 1/3octave to the next doubling .

this is helpfull for figuring where a feedback occurs in a PA feed

if you have a 31 band graphic , run your guitar through it and adjust the octave Q's by adding and or removing a set frequency , the note has not changed just the filtering

I hope i did not throw you off here its all related .
 

nickmm

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The Fundamental contains overtones/partials . You are reducing the volume of these.
*clementeharmonicseries.png
 

Maguchi

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I have used the tone knobs and I know what they do, give it some more bass or roll it off. But every note vibrates at a certain frequency. An 'A' is an 'A'. When you turn the tone knob and add more bass, is it still considered an 'A'? or is it like a pitch shift. How can an A be modified when it has its own frequency of say 440Hz. I mean to me, speaking in terms of a piano, all the keys are in a spectrum going from bass, to alto, to treble etc. I know all note to the right become higher or more trebley and to the left become more bassey. I guess there is no exact line you cross where you are not in bass anymore and now it treble. Anyways to me going more bass, means going down the SCALE using DIFFERENT notes to the left with a different wavelength. If an A vibrates at a certain pitch and you roll the tone knob adding or removing bass/treble how is it still an A? Is it still an A? Or is it moving the note down a half step or something? I'm just confused at what is going on here. I don't even know if I'm making any sense. It's hard to explain.
Or... does every note contain characteristics of lows mids and highs? That's the only thing I can think of. But aren't lows mids and highs also different frequencies? So if an A resonates at the assigned 440Hz, that is the frequency isn't it? A bass note would have a different frequency. How can a note contain multiple frequencies.
I know a perfect midi tone sounds terrible. It's perfect but all analogue instruments are imperfect yet sound way more beautiful than a midi.
Or is this a case of improper words being used? Like how people call a whammy bar, aka, vibrato tailpiece a tremelo arm, which it isn't tremolo. That is an actual case of the frequency of the note changing.
Vibroluxer beat me to it. The musical and scientific term "timbre" can be used to clarify what is meant when talking about changing the character of a note using the tone knob. On Google timbre is described as "the character or quality of a musical sound or voice as distinct from its pitch and intensity." For example "trumpet mutes with different timbres." So the tone knob or fader on a guitar, amp, EQ pedal or mixing board will change the timbre of note(s) played on a guitar making it darker, brighter, crisper, muddier etc.
 
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wabashslim

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What they said - the tone control is decreasing the harmonics of whatever note you're playing, starting with the highest on down. And to clarify, you're not "adding bass". A passive tone control cannot add anything, it can only subtract, but when rolled off the ears hear proportionately more lows - and the amp focuses its energy into the remaining tone so it does sound like more bass.
 

WalthamMoosical

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If you use a pair of vice grips to turn the treble knob past ten, or maybe fifteen, can a Telecaster then produce deadly icepick treble?
Yes and no. Deadly treble sure, but it's not called "icepick." It's called "vicegrips." If you've never heard that term before, well, I guess you never tried to access those enhanced sonic possibilities before.
 

TomBrokaw

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To expand a bit on what others have said about overtones, harmonics, and timbre... The filters commonly used on synthesizers provide some good examples of this. There's a great write up here, but I'll TLDR with a few examples.
In NIN's "Right Where It Belongs" there's a filter on Trent's voice; at about 3:05 the cutoff frequency is raised, making his voice more clear and present.


There's a nice example on Steve Murano's remix of Cry Little Sister, from The Lost Boys. The intro synth riff is fairly static until about 0:47, where the low pass filter, which is very similar to a guitar's tone control, starts to lower the cutoff frequency, dropping that synth into the background. A few seconds later, at 0:55, a second synth with a high pass filter, which is similar to the inverse of a guitar's tone control, is introduced. It sounds very thin at first but by the time the drums kick in at 1:10, it's nice and beefy


Finally, think of a wah pedal. That's just a bandpass filter with the Q controlled by the rocker/potentiometer. It's not changing the fundamental of the note the guitarist is playing, just which overtones are emphasized.
 

AAT65

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I guess the next question is which of these timbral characteristics distinguishes a guitar from a saxamophone??
The short answer is lots of things! Different harmonics are more or less present, that’s a major factor: but also the envelope. The overall attack / decay of a plucked or strummed string is pretty distinctive, and within the note each harmonic will also die away at different rates.

The waveform shape and the prominence of the partials. The Reed produces more of a sawtooth wave verse the sine wave of a string.

Nice waveform pictures! However the makers of guitar synths would kill for a guitar which has sine-waves coming out of it to make their pitch extraction easier. Guitar waveforms can be complex enough that the fundamental is actually lower than the first or second overtone.
A flute probably comes as near to a sine wave as a traditional instrument can get, but even that has quite a lot of noise (breath) mixed in.

To expand a bit on what others have said about overtones, harmonics, and timbre... The filters commonly used on synthesizers provide some good examples of this.
Playing with synth waveforms teaches you that a sine wave is nice to listen to - but a bit dull. If you want something you can get some feel of character out of you need something with harmonics that you can then modify with filters, and to give real bite you can start to add slightly detuned oscillators into the picture. A string instrument like a piano or a guitar has some detuning of higher harmonics which contribute to the timbre.

The drawbars on an organ are another good example of how overtones build up the sound. Again one drawbar is sine-ish, adding elements from other drawbars gives you more interesting sound.
 

nickmm

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The short answer is lots of things! Different harmonics are more or less present, that’s a major factor: but also the envelope. The overall attack / decay of a plucked or strummed string is pretty distinctive, and within the note each harmonic will also die away at different rates.


Nice waveform pictures! However the makers of guitar synths would kill for a guitar which has sine-waves coming out of it to make their pitch extraction easier. Guitar waveforms can be complex enough that the fundamental is actually lower than the first or second overtone.
A flute probably comes as near to a sine wave as a traditional instrument can get, but even that has quite a lot of noise (breath) mixed in.


Playing with synth waveforms teaches you that a sine wave is nice to listen to - but a bit dull. If you want something you can get some feel of character out of you need something with harmonics that you can then modify with filters, and to give real bite you can start to add slightly detuned oscillators into the picture. A string instrument like a piano or a guitar has some detuning of higher harmonics which contribute to the timbre.

The drawbars on an organ are another good example of how overtones build up the sound. Again one drawbar is sine-ish, adding elements from other drawbars gives you more interesting sound.
A guitar has a complex sine wave as all string instruments do.
You are mixing up the concepts of ADRS envelope and waveform.
 

AAT65

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A guitar has a complex sine wave as all string instruments do.
You are mixing up the concepts of ADRS envelope and waveform.
Complex sine wave is an oxymoron. It’s the presence of harmonics that gives the complexity, and once you add harmonics it is not a sine wave.
And I’m not mixing anything up at all, I am pointing out the dynamic nature of string instrument sounds in particular. All natural sounds have an envelope, which can be fairly square for a sax or flute if you don’t run out of breath or something more complex which we can approximate as ADSR. Within a note different overtones die away at different rates, thereby giving a changing waveform over time. This is part of a guitar’s timbre. (In a synthesiser people go to great lengths to apply different envelopes to different oscillators, trying to approach the natural complexity of a guitar or piano note.)
 

nickmm

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Complex sine wave is an oxymoron. It’s the presence of harmonics that gives the complexity, and once you add harmonics it is not a sine wave.
And I’m not mixing anything up at all, I am pointing out the dynamic nature of string instrument sounds in particular. All natural sounds have an envelope, which can be fairly square for a sax or flute if you don’t run out of breath or something more complex which we can approximate as ADSR. Within a note different overtones die away at different rates, thereby giving a changing waveform over time. This is part of a guitar’s timbre. (In a synthesiser people go to great lengths to apply different envelopes to different oscillators, trying to approach the natural complexity of a guitar or piano note.)
I'll rephrase if you like. A single guitar note has a complex series of sine waves.

I get where you are coming from. I prefer to keep the explanation simple and fundamental.
 
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24 track

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If you use a pair of vice grips to turn the treble knob past ten, or maybe fifteen, can a Telecaster then produce deadly icepick treble?
no but if you do that the person standing in front of your amp will drop to their knees and beg to have run your finger nails over a chalk board instead as you decalsify their spinal column. just sayin!
 

Bendyha

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A joyous phenomenon, is to hear the way the tone changes coming from an accordion as the player passes your balcony on their way down after having been thrown from a higher flat, it gets flatter as it passes, then, when completely flattened, sounds best.
 

Guran

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I have used the tone knobs and I know what they do, give it some more bass or roll it off. But every note vibrates at a certain frequency. An 'A' is an 'A'. When you turn the tone knob and add more bass, is it still considered an 'A'? or is it like a pitch shift. How can an A be modified when it has its own frequency of say 440Hz. I mean to me, speaking in terms of a piano, all the keys are in a spectrum going from bass, to alto, to treble etc. I know all note to the right become higher or more trebley and to the left become more bassey. I guess there is no exact line you cross where you are not in bass anymore and now it treble. Anyways to me going more bass, means going down the SCALE using DIFFERENT notes to the left with a different wavelength. If an A vibrates at a certain pitch and you roll the tone knob adding or removing bass/treble how is it still an A? Is it still an A? Or is it moving the note down a half step or something? I'm just confused at what is going on here. I don't even know if I'm making any sense. It's hard to explain.
Or... does every note contain characteristics of lows mids and highs? That's the only thing I can think of. But aren't lows mids and highs also different frequencies? So if an A resonates at the assigned 440Hz, that is the frequency isn't it? A bass note would have a different frequency. How can a note contain multiple frequencies.
I know a perfect midi tone sounds terrible. It's perfect but all analogue instruments are imperfect yet sound way more beautiful than a midi.
Or is this a case of improper words being used? Like how people call a whammy bar, aka, vibrato tailpiece a tremelo arm, which it isn't tremolo. That is an actual case of the frequency of the note changing.

A is, as you say, 440 Hz. It is also 220Hz and 880 Hz. Doubling or halfing the frequency will give an A.

The A string of a guitar has a fundamental frequency of 110 Hz. It also contains overtones, multiples of 110, so there's 220, 330, 440, 550, 660, 770, 880 Hz and so forth. The tone knob, when turned down, reduces the content of the higher frequences and thus changes the timbre.
 




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