Scale Length and Fret Spacing

[Franko]

Hello everyone,
As some of you may know, I recently created a thread because I am in search of a 12th fret acoustic "go-to, couch" guitar. Why a 12th fret you ask? Well, I played a couple of them and like them for the size and feel. I played several guitars that are "smaller" like the GS Mini and some of the parlor size guitars. I also played a Taylor 512ce? with 12 frets, slotted headstock and it was amazing! That will be my next purchase by the way, but I am looking for something in the price range of $200 to 500 max. In my search I've come across some very interesting things. I wondered why Taylor didn't make the GS with fewer frets and make it a 12th fretter? Wouldn't that have made more sense? The frets spacing on those feels really small to me. I played a really cheap used Samick ST91 "3/4 size" guitar that was a 12th fretter and felt really good. The scale length on it was 23 1/4" which is 1/4" shorter than the GS but felt a whole lot roomier. I guess what I am wondering is if you have a shorter scale and fewer frets, is it actually roomier between frets? Also, does "3/4 size" mean anything when it comes to this? Isn't it more about the scale length as opposed to the size with size being more of a body thing?

[rick-slo]

Same scale length, same distance between frets. It does not matter if you have a 14 or 12 fretter.
Check this website:
http://www.buildyourguitar.com/resou...s/fretdist.htm

[pb+j]

You set scale length for a guitar--it could be any length. The fret spacing is always proportional to that length--the 12th fret will be in the middle, fifth fret will be between the 12th fret and the nut, etc. You could have a 25.5 inch scale with the 12th fret at the body, if you wanted: you would just make the body bigger.

Personally i find that a 12 fret guitar makes it hard to play some stuff I like to play, but they tend to have in my experience a sweeter sound, maybe because the scale length is shorter or the ratio of body to neck is greater.

[Howard Emerson]

Originally Posted by Franko

Hello everyone,
As some of you may know, I recently created a thread because I am in search of a 12th fret acoustic "go-to, couch" guitar. Why a 12th fret you ask? Well, I played a couple of them and like them for the size and feel. I played several guitars that are "smaller" like the GS Mini and some of the parlor size guitars. I also played a Taylor 512ce? with 12 frets, slotted headstock and it was amazing! That will be my next purchase by the way, but I am looking for something in the price range of $200 to 500 max. In my search I've come across some very interesting things. I wondered why Taylor didn't make the GS with fewer frets and make it a 12th fretter? Wouldn't that have made more sense? The frets spacing on those feels really small to me. I played a really cheap used Samick ST91 "3/4 size" guitar that was a 12th fretter and felt really good. The scale length on it was 23 1/4" which is 1/4" shorter than the GS but felt a whole lot roomier. I guess what I am wondering is if you have a shorter scale and fewer frets, is it actually roomier between frets? Also, does "3/4 size" mean anything when it comes to this? Isn't it more about the scale length as opposed to the size with size being more of a body thing?

Scale length is scale length. It makes no difference how many frets the guitar has. The shorter the scale, the closer together the frets are.

Period the end.

So what does that mean when all of a sudden your logical brain thinks that your fingers should be cramped, but they're actually comfortable?

A quandary, huh?

Do you think, perhaps, that a particular body shape/size might change the center line of the neck, and how that might affect the way that particular neck will intersect with YOUR HAND?

Standing or sitting? Sitting on what?

12 frets to the body or 14? Overall length of the guitar and how far away from your body your hand ends up being, which will affect the angle of your hand to the fingerboard, etc?

You can figure this stuff out for yourself if you'll only make notes of your observations.

You can do this.

HE

[sdelsolray]

Yes, fret spacing is determined by scale length.

However, the location of the frets relative to the players left hand is often different between a 12 fret and 14 fret guitar, even with the same scale lengths. The ergonomics of having the left hand about two inches closer to the player's body means less left arm elbow angle (all other things being equal) and often results in more comfortable playing.

[Riverwolf]

Originally Posted by rick-slo

Same scale length, same distance between frets. It does not matter if you have a 14 or 12 fretter.
Check this website:
http://www.buildyourguitar.com/resou...s/fretdist.htm

Not trying to hijack.
I read the article and several more. I read that the 12th fret is always the exact middle of the scale.
But why?
And why 17.817?
Why 12 or 14 frets? What would would happen if only 10 were used?
Or if the 12th fret were not in the middle?
Would it just sound bad?
Then how do fret-less guitars work?
Why do I need to know any of this?

[JJO]

I'm not an expert by any means, but here's my basic understanding ... the midpoint of the string is the octave (because physics), so if you want to play western music with a traditional 12 semi-tone scale, it needs to be the 12th fret at the midpoint.

You COULD put any fret there, but then you could not construct an instrument that can play all of the "correct" notes for western music because you'd be dividing the rest of the scale up differently.

The 12-fret vs. 14-fret issue is completely different--that's a matter of where the guitar's neck meets the body, not an issue of the scale itself. The 12th fret is the mid-point (octave) in either case.

[warfrat73]

It's math. Don't make me explain math.

It's determined by wave lengths, nodes, etc. That's why you get an octave directly in the middle, and that 5th fret (1/4 scale) and 7th fret (1/3 scale) produce good harmonics, because, like the octave, they are nodal points in the scale.

There's nothing stopping you from making a 10 fret to the body guitar, but the octave will still fall directly in the middle of the scale length (give or take a tiny bit based on true/artificial harmonics, string mass and string diameter... that's why we have compensated saddles). But the way we have it set up now, and based on the conventions of western music, the twelfth fret is the octave, and mathematically, that falls directly in the middle. Move it and it will violate our (western) expectations for chromatic scale progressions. Instead of an E or a Ab you'll end up with notes in between that don't fall in line with our musical lexicon, but that might be perfectly at home in some non western musical traditions.

Originally Posted by Riverwolf

I read that the 12th fret is always the exact middle of the scale. But why?

Because by definition and the laws of physics, that is where the octave note lives.

Originally Posted by Riverwolf

Why 12 or 14 frets? What would would happen if only 10 were used?

Many factors go into that, including body shape and final geometry of the instrument. Assuming the body size remains unchanged, making the neck longer or shorter forces the bridge and associated bracing to a new position. The spacing between the frets is unchanged if the scale length remains the same.

Originally Posted by Riverwolf

Or if the 12th fret were not in the middle?
Would it just sound bad?

It would sound out of tune and the customer would want a refund.

Originally Posted by Riverwolf

Then how do fret-less guitars work?

Fretless instruments, guitar or otherwise, depend on the player placing their finger in the right spot. Too close to the bridge and the note is sharp. Too far from the bridge and the note is flat.

Originally Posted by Riverwolf

Why do I need to know any of this?

Because humans are curious.

[rick-slo]

Originally Posted by Riverwolf

Not trying to hijack.
I read the article and several more. I read that the 12th fret is always the exact middle of the scale.
But why?
And why 17.817?
Why 12 or 14 frets? What would would happen if only 10 were used?
Or if the 12th fret were not in the middle?
Would it just sound bad?
Then how do fret-less guitars work?
Why do I need to know any of this?

Because there are twelve notes in an octave. Going up from a note to the same note an octave higher (say the E on the open fret to the E on the 12th fret) and the frequency is doubled. The frequency is doubled when the string length is halved (thus the 12th fret is at the middle of the string - please ignore intonation arguments ).

[Larry Pattis]

Originally Posted by Howard Emerson

<<snip some very-correct stuff>>

You can figure this stuff out for yourself if you'll only make notes of your observations.

You can do this.

HE

The problem, Howard, is that a whole lot of folks reject the notion that accumulating actual data/specification-info is good, and that this kind of thinking is the work of the devil...and that the only way to true happiness is to be blissfully ignorant in regards to having an actual understand of what might feel most-comfortable (or to work-best) for any given player.

It's a mystery to me, but there you have it.

[Franko]

Thanks everyone for your responses. So what I'm gathering here is some say scale makes no difference in tuning and I understand that the twelfth fret is the "center". I'm wondering though, try to follow me here...say you have a guitar that has a scale of 25" and a guitar with a scale of 24". Ar you telling me the 12th fret on both guitars would be the same distance from the nut? So if I like the "feel" of one guitar say Taylor with a scale length of 24 7/8", then the GS Mini just feels smaller because of the scale length which is 23 1/2 not because of at which fret the neck joins the body? Okay...I think I understand. So my Taylor 814 has a scale length of 25 1/2 and it feels really good and the 522 feels awesome. There's only about a 5/8" difference. I also do like the feel of playing with a capo on the second fret...hmmmm....the difference between the 522 and the GS Mini is a whole 1 1/8" difference! That makes it feel smaller I guess. So, I think my search will keep me at a scale length between 24 1/2" to 25 1/2". I can only assume, the 12th fretters feels good because of the closeness and the angle of my hand. I think I understand. Thank you everyone!

[sdelsolray]

Originally Posted by Franko

…I can only assume, the 12th fritters feels good because of the closeness and the angle of my hand.
…

It has more to do with your elbow and the forearm angle. Let me explain:

1) Hold your left upper arm against you body with your right hand making sure your left elbow is also touching your rib cage.

2) Extend your left forearm straight out in front of your body with the palm of your left hand facing up.

3) Rotate your left forearm to the right (towards your stomach) pivoting only at the elbow. Note how far it will rotate towards the right.

4) Rotate your left forearm to the left (away from your stomach) pivoting only at the elbow. Note how little it will rotate towards the left.

It is #4 above that is stressed by the difference between a 12 fret and 14 fret guitar, and, to a lesser extent, by the scale length.

[dwstout]

Originally Posted by Franko

Thanks everyone for your responses. So what I'm gathering here is some say scale makes no difference in tuning and I understand that the twelfth fret is the "center". I'm wondering though, try to follow me here...say you have a guitar that has a scale of 25" and a guitar with a scale of 24". Ar you telling me the 12th fret on both guitars would be the same distance from the nut?

NO! The 12th fret is always one half way between the nut and the saddle. On a 25" scale, it's at 12.5" On a 24" scale it's a 12".
The real difference between a 12 fret and a 14 fret guitar is the BODY. A 12 fret guitar just has a longer body so the neck attaches to the body where the 12th fret is.

[pb+j]

Imagine a string two feet long, tuned to A 440. If you set it vibrating, and touch it exactly in the middle, it will make a note an octave higher (@880). If you touch it 1/4 of the way (where the fifth fret is), it will make a note an octave higher still. It's the physics of a vibrating string. These are called "nodes:" we know them on the guitar as "harmonics." Western harmony is based on this--the standard, basic intervals conform to the nodes on ANY vibrating string. No matter how long, how heavy, how light: the nodes will have the same relationship to the starting pitch. It was actually an important basis for roman and greek architecture--the harmonic proportions of twice as high, half as high, a third as high, a fifth as high, etc.

Fretless instruments are under the same laws of physics, a fretless player puts his finger at almost exactly the same place. Almost--guitars are never quite in tune. It's hard to understand and explain, but a guitar can really only be completely in tune in maybe one key at a time--standard tuning compromises the "true" note a little. Players of instruments with no fixed pitch are often irritated by guitars, which always sound out of tune. I can hear this if I'm playing upright bass--the thirds often sound sort of off. You can hear it if you start to play a tune correct the tuning, and then switch to a different tune in a different key. You will likely need to retune