Freq Respns

[trem]

Bare with me here please -
1. What is the "typical" frequency response of your "average" guitar.? Say a Strat or a LP.
The lowest open note and the highest fretted note you can get (in Hertz).....round numbers are fine.
Is it something like 80 - 1,300 Hz .?
Thank You

[Chuck H]

The low E is actually E2 and is 82Hz
The high E, last fret on a Les Paul bent up in pitch one tone is E6 and is 1318Hz

But these are just the fundamental notes and a guitar does not generate a sine wave. So there are harmonics well above these tones that should be considered because without them guitars wouldn't have a timbre.

There are also circumstances under clipping conditions where harmonics below the fundamental are produced.

And this doesn't take into account new seven string guitars.

[Enzo]

yes^^^

That having been said, I'd say under 80-Hz rarely matters to a guitar. Guitar speakers by their nature tend to roll off somewhere in the 3k-5kHz area. The amps usually have more bandwidth than that, but you note you never see amplifiers for electric guitar with a tweeter. So the overtones are certainly important, but we don't need sparkling treble like a PA cab.

[Leo_Gnardo]

Chuck's got the strings covered! Now how about "pick attack." Some players want to hear a kick-drum-like THUMP as the pick lets go of the string. That can easily reach down to 40 Hz. It can sound pretty thin in systems limited to say 80 Hz. But, not everybody wants that.

Besides seven-string, whammy-down notes also reach down, possibly an octave, depending on the guitarist. Yeh, Eddie. And me. We do that. Honest, I've busted whammy bars. Little ol' me, who knew? But that's beyond average.

[trem]

The low E is actually E2 and is 82Hz
The high E, last fret on a Les Paul bent up in pitch one tone is E6 and is 1318Hz

But these are just the fundamental notes and a guitar does not generate a sine wave. So there are harmonics well above these tones that should be considered because without them guitars wouldn't have a timbre.

There are also circumstances under clipping conditions where harmonics below the fundamental are produced.

And this doesn't take into account new seven string guitars.

yes^^^

That having been said, I'd say under 80-Hz rarely matters to a guitar. Guitar speakers by their nature tend to roll off somewhere in the 3k-5kHz area. The amps usually have more bandwidth than that, but you note you never see amplifiers for electric guitar with a tweeter. So the overtones are certainly important, but we don't need sparkling treble like a PA cab.

OK...so you two guys pretty much hit on what I was wondering.
If a guitar high frequency is (round numbers) 1.3kHz...why do guitar speakers kind of peek at 5-6k.?
When Chuck says that a guitar does not generate a sine wave...does he mean a nice clean/round wave, or is he talking about something else.?
Thank You

[The Dude]

OK...so you two guys pretty much hit on what I was wondering.
If a guitar high frequency is (round numbers) 1.3kHz...why do guitar speakers kind of peek at 5-6k.?
When Chuck says that a guitar does not generate a sine wave...does he mean a nice clean/round wave, or is he talking about something else.?
Thank You

The reason is, as Chuck said, " ...there are harmonics well above these tones that should be considered because without them guitars wouldn't have a timbre."



Guitar is not a simple wave form like a test tone. There are all sorts of harmonics generated. It will look something like the attached picture. There are higher frequency harmonics riding on the fundamental tone.

[Enzo]

Consider too that an amp with response down to 80Hz doesn;t hit a brick wall, that is simply the freq it starts is rolloff.

Just google "sine wave" and an image of one will appear. Then compare that to the scope image Dude presented.

[trem]

Yeah...that is an interesting pic.
Do all string instruments behave like that.?
If you pic'd a Viola, would it create a frequency greater than the freq of its highest note.?
I suppose it would.

[The Dude]

Disclaimer: The pic I posted may or may not be a guitar. I posted it only as an example. For all I know, it could be a viola.

Most all sounds are made up of complex waveforms. It's not exclusive to stringed instruments. Few are simple-fundamental tone only sounds. Test tones being one, some keyboard tone generators, which are basically test tone generators that you can modulate or shape, etc. The harmonic content (how it is different from one sound to another), is how sounds are differentiated. It's how, for example, our ear can tell the difference between a guitar sound and say a saxophone sound. That's why, as others have said here, it's important in most cases to include this information when you amplify it. Sure you could use a speaker with limited response or radically EQ the guitar signal so as not to include much in the way of harmonic content, but it's going to sound less like a guitar and more like a test tone, which isn't normally very desirable.

[Leo_Gnardo]

Do all string instruments behave like that.?
If you pic'd a Viola, would it create a frequency greater than the freq of its highest note.?
I suppose it would.

Not just string but ALL instruments, except sine wave oscillators. Overtones - is what makes life interesting. Without which, music could be awful boring. Some flutes & recorders approximate a sine wave when played quietly, or a Hammond organ with only one drawbar pulled, and thru a plain amp not a Leslie. Hammonds are very interestng instruments because they let you "build a waveform" with fundamentals and varying amounts of a series of overtones you select by pulling the drawbars. Heck you can even leave out the fundamental and pick a couple odd upper "partials" for an unusual tone, and many top players do exactly that from time to time.

The other side of this, is all waveforms are built of collections of sine waves, the most simple of waveforms. Look up Fourier. He was the mathematician that proposed this idea back in the early 1800's. Mathematics meets music, and everything else in the whole universe. Just amazin' !!! The whole place is vibrating.

[trem]

Fourier.
10-4
Searching Yahoo now

[Enzo]

Something you might think of as clean and pure - a flute - is not making sine waves. In fact, in trying to find an instrument around the shop back in my music store days, I found I could make the best sine wave with my own voice. All the actual instruments had some sort of character to their waveform.


Listen to some sine waves. I am sure there are some on google for the finding, or any test tone record. Listen to them. They are just a steady tone, no sound qualities to it.

[Alan0354]

The low E is actually E2 and is 82Hz
The high E, last fret on a Les Paul bent up in pitch one tone is E6 and is 1318Hz

But these are just the fundamental notes and a guitar does not generate a sine wave. So there are harmonics well above these tones that should be considered because without them guitars wouldn't have a timbre.

There are also circumstances under clipping conditions where harmonics below the fundamental are produced.

And this doesn't take into account new seven string guitars.

I never even stop and think about this!!!! Middle C(3rd fret of A string) is 261, next C(1st fret of B string) is 522, then 8th fret of high E is 1046, then 20th fret is 2093. I think the bending of the last note at 22nd fret is E# and is 2636 which is one octave higher.

I never thought the range is so narrow!!!

[Leo_Gnardo]

Fourier.
10-4
Searching Yahoo now

Wikipedia might be more the place. What do those yahoos know anyway.

Fourier transform, Fourier analysis, Fourier series. Yeah a lot of math. It all started to come clear to me in soph math "Introduction to Partial Differential Equations." You don't have to get into brain-withering math to appreciate it though.

Just the first 20% of the Fourier series article is very instructive. After that it gets into head bangin' math. OW!

Fourier series - Wikipedia, the free encyclopedia

I hope you don't lose your appreciation for music when you find it's made of math. Don't worry, just boogie!

[trem]

Gotcha...Thanks (Leo and Enzo)
I could not figure out how a guitar with a maximum freq of 1.3kHz could fill a speaker with 5-6kHz.
Never seen the question asked before...was kind of embarrassed to be the first one.
I guess if I crank my scope, I guess I can see it straight from the guitar.?
What does a Humbucker put out...a few hundred millivolts.?