Is the 12th fret the exact center of the string length? The reason I ask this is when tuning I notice that if I fret and play any of the strings at the 12th and then move down to the 13th and play the same string at the fret board (in effect making the 12 fret act as the bridge) the sound is remarkably close if not exactly the same. Is this why intonation is so important? Does it actually center the string? This may be an elementary observation to some but it's helping me understand more about the structure of the guitar. Thanks in advance for any input.

If you play for example the E string open, and then at the 12th fret you are playing an E one octave higher. It is the same for all of the strings, fretted at the 12th fret is one octave higher than that string/note played open.
Setting your intonation makes sure that the note you play is exactly the note it is supposed to be, not sharp or flat.

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I didn't Lose my mind, I traded it for this guitar.

You are on the right track. The 12th fret is indeed half the scale length but only in theory. In practice there are small differences in the length of the two halves and yes this is why one reason intonation adjustments are necessary.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

Thanks Chet, i'm aware of the 12th fret octave but what I need to know is why does the string sound the same when plucked on the fret board while being fretted at the 13th. (Which makes the 12th fret act as the bridge) It leads me to believe that the 12th fret is the center of the string length although I've never read or heard that before.

Yes.
Look up.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

The precise answer to this question is no...it's not the exact center of the string length otherwise all of the saddles on the bridge would be positioned directly next to each other instead of being staggered as they are.




Maybe it's just me but your explanation is a bit confusing to me here. Are you saying that the notes you play on the 13th fret sound (nearly) the same as they do at the 12th fret? If that's the case then this isn't a problem with intonation...it's more likely a problem with either a high (or low fret) or possibly the bow of the neck...or both.

CAFeathers touched on this a little bit but I'll expand it for ya. Assuming that a guitar is setup correctly, then the note at the 12th fret should be one octave higher than the open string. It basically works the same way as it does on a piano...if you hit a "middle C" on a piano then move up 8 white keys, you are still at a C, only one octave higher. Looking at the low E on a guitar...the 12th fret is still going to be E, just one octave higher and then the octave repeats itself...in other words, the note at the 13th fret should be an F that is one octave higher than the first fret, the note at the 14th fret is going to be an F# one octave higher than the second fret and so on...

Now if this is NOT what is happening on your guitar (again your explination confused me) it could mean that you have a low 12th fret...in other words, when you press your finger down at the 12th fret, the string is actually hitting the 13th fret and not the 12th fret. Again this can also happen as a result of having too much bow in the neck which would require a truss rod adjustment (not recommended for beginners as you CAN snap the truss rod leaving the neck virtually useless!). If this is in fact the case, then I would recommend taking the guitar to a good pro for a proper setup.



Intonation, or the guitar "being in tune with itself" in a nut shell means that the 12th fret harmonic is going to be the exact same pitch as the note as fretted at the 12th fret. This is changed by moving the saddle on the bridge back and forth thus changing the scale length of the string so that E at the 12th fret we just talked about is really an "-E-" and not an E sharp or E flat. For all practical purposes what this means is that if you play a "G" on the high E string at the 15th fret and your intonation is off, the G may actually be flat or sharp making your guitar sound "out of tune". There are certainly other factors involved with this but that's the nut shell version .

Also for the sake of mentioning it...and I realize this is a bit advanced for a beginner but...remember that guitars are NOT perfect instruments when it comes to notes being "perfectly in tune"...even if the guitar is set up correctly. Ideally in a perfect world, an "E" should be an E regardless of whether it's an open low E, an E played at the 2nd fret of the D string, the 9th fret of the G string, the 5th fret of the B string, etc.. The reality of the situation however is that these notes are usually just a little bit off...just a hair flat or sharp. 'Tis the nature of the beast. A lot of folks over the years have tried to find ways around this...compensating frets certainly come to mind (you can easily look this up on the internet). For most folks it's not a problem at all beyond simply realizing that guitars simply aren't perfect. In fact, the way we tune our instruments isn't "perfect" but simply a balance so that most chords sound "in tune" in all keys (as apposed to everything being perfect only in certain keys)...I forget the exact terminology in regards to this but again it's pretty easy to find this stuff on the net. Again this isn't really a big deal at all for most people as much as something to simply be aware of.



Hey...nothing wrong with that at all! We've all had to learn some place and that's one of the truly beautiful things about internet forums...those of us with more experience can help others with less experience to avoid some of the pitfalls some of us have had to learn the hard way! LOL!!! For everything in life there must be a first time .

I hope this helps!
Jim

When the intonation is set correctly, the 12th fret will be at the half-way point of the acoustically active section of the string. That changes from string to string. Thus the characteristic staggered appearance of the bridge.

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Thanks guys, it looks like I need to explain my question more clearly. soggycrow gets what I'm after. Here it goes again - this may get a bit wordy but bear with me - If you play a note (plucking the string at or around the pick guard area) on the high E string fretting it at the 12th fret you get an E note. If you move your hand down to the 13th fret and pluck the string at or around the 5th fret (anywhere between the nut and the 12th) you also get an E note. lomitus, you mentioned harmonic. This is what I'm refering to. The fact that it's the same note infers that it must be the center of the string but when you consider the saddle positions it disproves the theory. Like you said lomitus, it's the nature of the beast, but food for thought nonetheless.

Without calling on the laws of physics to confuse you, you already have your answer but you are confused by all the details. Yes, the 12th fret is theoretically the halfway point of the length of the string. Reasons that take much complicated explaining dictate that it is not "perfectly" halfway in practice and that's why we need to individually intonate each string. Nevertheless it is the theoretical midpoint. Lay a tape measure along the fretboard of your Strat or Tele, butt the zero end up against the nut and you will find the crown of the 12th fret is 12.75" from the inside edge of the nut. The scale length of Strats and Teles is double that at 25.5".

I believe this is the answer you seek.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

As BMW said, I think you have the answer you were looking for in regards to scale length but that said, now I have a question. Ok...I'm not trying to be rude or insulting or anything here so PLEASE don't take it that way but...I'm curious...errr...why would you be picking the guitar/string that way in the first place? Granted I've never tried it but I'm not sure I see the sense in picking the string between a fretted note and the nut?

Based on your explanation here, that is NOT a harmonic...a harmonic is when you pick the string (over the pickups somewhere usually) and you VERY LIGHTLY touch the string above a fret. At the 12th fret for example, by picking the string while just lightly touching it above the 12th fret (it can take some practice) you get a higher pitched version of the same note...assuming the intonation is set correctly (and if you already knew that, please forgive me...I wasn't trying to be rhetorical or insulting).

Either way since it looks as though you're trying to really understand how and why a guitar works (which in my humble opinion is a really good thing), I would like to recommend snagging a copy of "How To Make Your Own Electric Guitar" by Melvin Hiscock. It's a really good read in that it explains the "hows" and "whys" of electric guitars (including a really good chart with common scale lengths!) without going in to too much science and detail. Basically the author makes 3 electrics in the book and shows you how step by step...you can probably even order a copy through your local library.

Peace,
Jim

When I was 10 years old and got my first guitar I did even weirder stuff than that. Some people just mess around to experiment. Obviously EVH did that stuff too because he actually used one of those things as the introduction to the song, "Runnin' With The Devil" when he raked the strings between the nut and the tuning machines. Most people think that was a note run on a piano but it wasn't.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

You know how difficult that is to do on a Peavey EVH Wolfgang! Yes, this is a EVH guitar and there is almost no room because of the string tree bar. I'm noting this because I've been going back through VHI and VHII recently.

On topic: the reason for this is really simple: plucking on the bridge side at the 12th fret is the same as plucking on the nut side fretting the (13th) fret. The reason I parenthesized 13th is because, in actuality, you are fretting the 12th fret from that direction. QED.

Pretty sure EVH used the Franken-Strat for VH1.

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Just think of how awesome a guitar player you could have been by now if you had only spent the last 10 years practicing instead of obsessing over pickups and roasted maple necks.

Most definitely. Do you have a spare $25000?

Sunburst

In laymans terms. The high E string is about as near the 0 saddle point as your going to get on a correctly intonated guitar. The theory goes that the rest of the saddle positions are dependant on string thickness, to mathematicaly assess their positioning back from that theoretical zero point. It doesnt work and you cant accurately set your intonation like that because of flaws in string manufacture. Inaccuracies in thickness and material consistency.

What your hearing is correct. Theres 100cents difference between one note and the next, example A-Bb. Its stupidly hard (nigh on impossible) to hear any difference of more than 20 cents, without having a sounding refrence note. You will hear these differences when playing chords as your brain learns to recognise the differences in intervals between notes. For instance you may hear that the F# (maj3rd) note sounds slightly off in relation to the D note on the 3rd fret of a open Dmaj chord. I picked on the major 3rd interval because if its a tiny out it sounds miles out.

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No no and no