Official Luthiers Forum!

I have been wondering about the effect of scale length on the sound of a guitar. The recent discussion of the definition of OOO and OM model Martins got me thinking about it. What is the effect of scale length on sound?

_________________
53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

It's hard to explain and depends on building style, in particular bridge placement, but I'd say a bit more warmth, a bit less sustain. I think a short scale will "let go of a note" faster than a longer scale, which depending on what you like to play can be a good thing. Remember, you will have less string tension so keep that picture in your mind as you build.

Hi Wayne,
Just curious...what size or design of guitar are you planning to build with this shorter scale?

I just finished a 000-12 fret and I could not be happier with the sound. It has a 24.9 scale. It plays like a dream. The sustain is a bit less than my last 000, but the notes seem very positive. As I am a longtime fingerpicker it really suite my needs. I made a number of abnormal adjustments during the building process and thankfully my gamble was correct and everything worked out great.
If your planning to use a shorter scale...go for it!
Good luck.
Walter

This issue has been a question in my mind too. I have an old Yamaha guitar that plays so well. I'm convinced that it's the shorter scale that make fingering easier, and the neck shape that makes it comfortable. I'm probably gonna try and duplicate it on my next one.

   Scale length can help in loading the top. A short scale will have less tension than long scale. So the more tension the more energy to drive the topwith the same gage strings.
john hall
   

I have personally found that the half inch difference between 24.9 and 25.4 makes no real discernable difference in isolation. I have built sister 14fret OM type guitars with the two scale lengths and find they sound and play exactly (or as near as my build ability allows) the same. In fact after about 30 secs I have to look carefully to see which one I'm using after I have subconsciously adjusted to the marginal differnce in fret spacing.

I think the fact that the 24.9 is usually used with 12 fret configurations and the 25.4 with 14 fret is much more important due to the moving of the bridge deeper into the lower bout on the 12 fret.

I have found no discernable difference with 10-47 or 11-50 strings either but if you went up to using ship's hawsers you might notice some effect on top loading, probably the bridge flying across the room.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Colin, are you back home yet?

Just wondering

_________________
Support the OLF! Bookmark our STEWMAC link Today!
Lance@LuthiersForum.com

[QUOTE=Colin S] I have found no discernable difference with 10-47 or 11-50 strings either but if you went up to using ship's hawsers you might notice some effect on top loading, probably the bridge flying across the room.

Colin[/QUOTE]

Interesting how people view strings differently. Those sound like electric guitar strings to me Colin I tend to use 12-53's - and me using pinless bridges too But then again I like to play guitars with a somewhat "manly" action on them as well as I like the tone a lot better - you just have to adapt your technique accordingly.

I play mostly in dropped and open tunings and I find that longer scale lengths work well here as you get a little extra tension without having to resort to "ship's hawsers". 25.75" (655mm) is a scale length I like and use a lot in the guitars I make.

Horses for courses.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Dave, I build very light tops and they suit the light gauge strings. I started using lights on my pre-war Martins,I started low for safety sake and never went up as I like the feel. I generally like 24.9 but use 25.4 on my dedicated DADGad guitars (with balanced Newstring sets). I find anything over 25.4 a bit of a stretch! I like the low tension of the 10s as I find it easier to get that percussive sound. Pulls and hammering are also easier to me. But of course it's a matter of what you're used to and playing style.

Dave, If you need any new strings Chatham dockyard is only half an hour from me I could get you a good deal!



Colin



Lance, yes I got home a couple of days ago.

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Colin,

Speaking of ship's hawsers, have you ever played one of Martin Carthy's guitars?

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

I guess I was sceptical that a 1/2 inch change would make a big difference, although it seems like a lot of subtle changes going on all at once. String tension, bridge location and fret spacing come to mind. I have read a few accounts of the history of Martin guitars, and I have never seens a good explanation of why a manufacturer would make a change like that.

To those of you that sell your guitars, do you find customers have a preference for a particular scale length? Or, are they mainly driven by a choice between body style and number of frets to the body?

_________________
53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

I think it's more in the style of music they play. Or maybe it's more what they have played and are used to. I know that those who use open or detuned tunings seem to prefer longer scale to keep the strings from flopping.

_________________
Tickle your guitar daily, and it'll tickle you back.

Walter, I have only built a dreadnaught to this point, although I have plans to try a different style soon. I recently got a copy of the SJ plans from this forum, so I think that will be my next project.

I guess its the engineering-nerd in me that wants to mess around with the different construction aspects.

_________________
53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

Yes Dave, I've played both his old 000 and also his newer 000-18MC. I first played it back in the late sixties at the Troubadour when he was trying to teach me Sovay. We also supported him on the same bill at Broadstairs a couple of years ago and he coveted my old OM28 so we swapped for a few songs. But do you know how many times he has had to have the neck reset on that old thing, and it's certainly a dome top now, but I love the zero fret.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Colin--welcome home! (Though that no doubt sounds more convincing from your wife.)
Yours and Dave's back-and-forth about string gauge is interesting. Can hardly believe you get any sound at all out of 10's! I'm a 13-56 guy, and love the sound. My guitars hold up well, and when 12's are put on, they really begin to "wimp" out. Yours must be built extremely light?

SteveSteve Kinnaird38667.6213194444

_________________
From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

Your Geekly Reader

That half inch difference doesn't do much objectively, but then again, this is so often a 'game of inches' that the differences can become important.

Some background: I thought I knew about strings until I started to build harps. Those guys _know_ about strings: it's the central problem in designing a harp. There are only so many ways you can put together a portable box that will take 1000 pounds + of string tension, but there are lots of different ways to lay out the strings. So I learned some stuff. More recently I've been conducting a few experiments with strings, and that's taught me some things, too.

All else equal, the longer strings will differ from the shorter ones in the following ways:
1) They will be at higher tension. As has been pointed out, this means that for a given amplitude of vibration there will be more energy available.
2) Because of the higher tension and greater mass (a longer string of a given size has to weigh more, right?) the 'impedance' will be higher. In some ways impedance is a measure of how hard the string can push on the bridge, and there's a frequency thing that gets in there, as well. The bottom line here is that a longer string can usually feed it's energy into the top faster, and often has a slightly different 'balance' to it's sound.
3) They will be at a higher 'percentage of tension': closer to their theoretical breaking point. This seems to have all sorts of ramifications. For one thing, strings at a higher '%T' have a 'truer' overtone series than slacker ones, and thus a more 'pure' tone. For another, they bend less, and thus require less compensation.
4) I've been looking at the old question of how much 'torque' force there is on the bridge, as the string tightens up twice per cycle. This, too, seems to vary depending on the %T of the string, with slack strings having relatively more torque than tight ones.
5) There's also Ralph Novack's idea that the 'longitudinal' wave in the string could have an effect on tone. This wave is analogous to a pressure wave in a long pipe that runs up and down the length. In a string the frequency turns out to depend on the length and material of the string, but not on the tension, with a longer string having a lower pitched 'L-wave', if you will. From what I've seen a fair amount of the energy you put into plucking the string goes into that 'L-wave', which, for most guitars, will be up around 4-5 thousand Hertz. I suspect that very little of that energy gets turned into sound, but the L-wave seems to interact with the other sorts of things the guitar string does, starting at about half it's frequency, and that might have an effect, as Novack conjectured. There's lots of stuff to be sorted out in this one, and I've got to get hold of the _real_ physics geeks on it.

My own feeling is that the main differences come from the impedance and bending/intonation effects, with the 'purity' of the overtone series being another contributor. As I say, I'm sure these effects are 'small' in an objective sense, but that doesn't mean they won't loom large in the world of music. And, of course, this does nothing to address the probably equally, if not more, important issues of bridge placement and brace design.

I am a fan of short-scale guitars. I've built with all of the scales mentioned and also with the 24.75 Gibson scale length, which I would suggest to anyone who is looking at building a J-185 size guitar.
I first stared making shorter scale guitars because they were easier for me to play. I have also read that players like Norman Blake moved from the big, long scale guitars to smaller, shorter Gibsons.
My favorite guitar to play was a pretty old Chicago-made Regal guitar. I had and played it for a long time and I thought that I'd use it as a model to design a guitar of my own, and I make quite a few of these little guitars and I call them the "Fatboy" guitar since they are short and wide. I also make the body a full 4-1/2 deep. The scale on this guitar is 24.25 and I use medium strings on it- lights are just too rubbery at that scale. I wish that I could let each of you folks who are wondering about scale lengths play one of these because with a scale that short you can more easily get a feel for how it's different from a longer scale guitar. I like it anyway, and it suits my hand and allows me to play better than a longer guitar.

_________________
Mark Swanson
Swanson Guitars
http://www.MarkSwansonMusic.com

[QUOTE=Steve Kinnaird] Colin--welcome home! (Though that no doubt sounds more convincing from your wife.)
Yours and Dave's back-and-forth about string gauge is interesting. Can hardly believe you get any sound at all out of 10's! I'm a 13-56 guy, and love the sound. My guitars hold up well, and when 12's are put on, they really begin to "wimp" out. Yours must be built extremely light?

Steve[/QUOTE]

I do build light tops, tapering to the edge and of course I tend not to use scalloped braces but more 'parabolic' (OK they're not true parabolas). I've never gone for out and out volume as, most of the time, I don't play in the Albert Hall but in small clubs or at home and have to balance with my wife's fiddle or Northumbrian pipes and her very sweet voice. The one time a louder guitar would be useful is when I sing as anything that would drown that out would be welcomed by many. But no they are plenty loud and I like the increased 'feel' of the light strings in more complex pieces. (Do I play complex pieces?). Tone and playability are the critical things. Oh and there is a wonderful thing that I stand in front of sometimes called a microphone!

Dave, Russell, I just heard last night that Eric Roche had died! What a great player, I saw him 3 or 4 times and was always blown away by his playing. I'm still trying to get my fingers around Faja Grande. What a loss and so young.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Hi Colin

I should have thought to tell you, he died on the 6 Sep.
A very very sad loss.

On the Scale discussion I do a lot in a 24.9" scale, a lot of the fingerstyle players seem to like it, I usually use 11-50's or 12-52/53's.