12 String design thoughts

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Jim
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12 String design thoughts

Post by Jim » Sun Jun 10, 2018 9:07 pm

Hi All,

Was just listening to a Fretboard Journal podcast with Todd Albright. He was talking about 12 string guitars- specifically 12 strings with heavy gauge strings tuned way down. Got me thinking.... love to play one set up like this- would add a really nice dynamic to a two acoustic guitar sound.
Anyway somewhere waaaay in the future I'd like to build a 12 string with this in mind. Anyone got any design/setup thoughts re this idea?
It'll probably stew away inside my head for a year or four before I have a crack....

Jim

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Mark McLean
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Re: 12 String design thoughts

Post by Mark McLean » Sun Jun 10, 2018 10:59 pm

Jim, that sounds like a great future project. A good example of that style guitar is the Leo Kottke signature model that Taylor used to make back in the 1990s (but has now been discontinued for many years). Forgive me if you already know it - but if you don't it could give you some ideas to start your thinking. The LKSM came in 6 string and 12 string versions. The 12 was a jumbo monster, intended to be played with heavy gague strings and tuned down to C#. 17 inches across the lower bout and also very deep (4 5/8 inches, which is half an inch more than a Martin drednaught). I played one once in a shop in Perth. It was big, and heavy, and had a really menacing presence. It also has a very simple, unadorned aesthetic which I like. Unfortunately the one I tried (being sold second hand) was horrible to play because some fool had strung it with lighter strings and tuned it up to concert pitch. It was tight and tinny and had high action - a real disappointment. But that was not the guitar's fault, and it probably would have been great if set up properly. There is a Fretboard Journal piece about the model and a video of Kottke playing it here:
https://www.fretboardjournal.com/column ... ure-model/

Kottke said that playing a twelve string is just like a six string, but lumpier. For what it is worth, here are my random thoughts about an instrument of this type:
Maybe use a longer scale length, or even fan fret multi-scale to keep the string tension down on the lower strings.
Blackwood or mahogany, definitely not rosewood (might get too boomy).
Needs a good stiff top to resist all that string tension. Sitka or Adi spruce. Avoid cedar.
Truss rod plus some CF bars in the neck.
I would consider putting CF rods in to reinforce the body too, like this example from Jan Brentrup
https://www.google.com.au/imgres?imgurl ... mrc&uact=8
Maybe a 6-pin bridge (two string per pin)
Definitely not a slotted headstock (although it looks cool, a real hassle to string up)

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kiwigeo
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Re: 12 String design thoughts

Post by kiwigeo » Mon Jun 11, 2018 8:40 am

Mark McLean wrote:
Sun Jun 10, 2018 10:59 pm

Maybe use a longer scale length, or even fan fret multi-scale to keep the string tension down on the lower strings.
I'd definitely consider a fan fret....but if you haven't made one before be prepared for a few challenges :)
Martin

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Mark McLean
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Re: 12 String design thoughts

Post by Mark McLean » Mon Jun 11, 2018 8:58 am

kiwigeo wrote:
Mon Jun 11, 2018 8:40 am
Mark McLean wrote:
Sun Jun 10, 2018 10:59 pm

Maybe use a longer scale length, or even fan fret multi-scale to keep the string tension down on the lower strings.
I'd definitely consider a fan fret....but if you haven't made one before be prepared for a few challenges :)
But Martin has already made all of the mistakes, and documented them for us. So, just read his blog on making his multiscale falcate OM, don't do what he did, and it should be fine

Jim
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Re: 12 String design thoughts

Post by Jim » Mon Jun 11, 2018 9:01 am

I love the multiscale idea- would be so effective making sure string tension is good. Thanks so much for the thoughts and the links Mark.
Martin are you a fan of the multiscale design having made and played one? Does look like a challenge to execute.

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kiwigeo
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Re: 12 String design thoughts

Post by kiwigeo » Mon Jun 11, 2018 9:13 am

Jim wrote:
Mon Jun 11, 2018 9:01 am
I love the multiscale idea- would be so effective making sure string tension is good. Thanks so much for the thoughts and the links Mark.
Martin are you a fan of the multiscale design having made and played one? Does look like a challenge to execute.
A fan of multiscale? The owner of the guitar loves it but as a builder it was a challenge and a lot of work. Because I was using falcate bracing the asymmetry imparted by the fan fretting added to the complexity of the build. Eg individual sec and prim braces had to be made up instead of making up blanks and cutting in half. If you're going for a straight string pull headstock then the options for headstock design are extremely limited. Time needs to be spent on bridge design as well. Most importantly of all...you need to do up a full scale drawing of the instrument to make sure everything fits together.
Martin

scripsit
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Re: 12 String design thoughts

Post by scripsit » Mon Jun 11, 2018 10:23 am

Jim wrote:
Mon Jun 11, 2018 9:01 am
I love the multiscale idea- would be so effective making sure string tension is good. Thanks so much for the thoughts and the links Mark.
Martin are you a fan of the multiscale design having made and played one? Does look like a challenge to execute.
Martin built the multiscale OM for me and I'm definitely a fan. It took about 4-6 weeks to get used to the fret angles and sort of recalibrate left hand muscle memory, particularly for shapes at the bottom three frets, but after that it feels very comfortable. I play it most days, and it sits in DADGAD most of the time. Swapping between the OM and my more conventionally fretted guitars is not a problem, but I definitely prefer the feel and sound of the multiscale. Being a 12 fretter helps.

I haven't played 12 strings for years, since my electric guitar days when I used a flat pick on acoustics and would thrash away at a cheap plywood top 12 in G and D tuning. I think fan frets on a 12 would be great for fingerstyle with altered tunings, but probably overkill for strumming in missionary tuning. For normal tuning, tuning down a couple of steps would make sense to me in any case: a long scale 12 tuned up to pitch can be a bit hard on the left hand finger tips no matter how you fiddle with the balance between bass and treble. I'm conscious that Kottke had a lot of problems with both of his hands back in the nineties, and after relearning with bare right fingers his sound changed considerably. I'm a sucker for the sound he got on 'My Feet are Smiling'.

The headstock thing is always an issue. Normal paddle heads are usually very neck heavy, but slothead 12s are a prick to restring.

Kym

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