Baritone 12 string

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Matthew Orifice
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Baritone 12 string

Post by Matthew Orifice »

has anyone approached trying to build one? i'm doing research currently to do just that, 28.6 scale for a GDGDGA tuning.... but i'm a tad ( read severely) worried about that much tension over that long of a scale.
electronically i'm looking at a hybrid acoustic bridge with a piezo and a mic, a single in the neck and a bucker in the bridge... thoughts suggestions?
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Bob Gramann
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Re: Baritone 12 string

Post by Bob Gramann »

With a solid body, you can make everything strong enough to support the tension (how big a neck can you reach around?). I would worry more about how much strength it would take to play it. It's electric, so you can use the lightest gauge strings per note that won't be too floppy.
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Beate Ritzert
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Re: Baritone 12 string

Post by Beate Ritzert »

With a .090" (or even .084") string a G can be achieved even on the standard guitar scale (that's the third fret on a 30" bass VI), tension feels fairly low. So with accordingly thinner strings You'd be able to do a G on Your scale. "Accordingly" can be calculated. I'd be surprised if it was not possible to realise Your project with the tension usually found on 12 string guitar sets.
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

i'm a bit of a gorilla (my other job is a blacksmith) so strength isn't a huge issue, i currently play a 6 in that tuning at 27" and .080 is a little lacking in the fundamental (the project i'm working with is paired with bagpipes and hurdy gurdy so i am the only low end) i'll dig around for a .090 thanks for the notes i will let y'all know where things go from here
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Beate Ritzert
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Re: Baritone 12 string

Post by Beate Ritzert »

The strings i use on my VI (a converted shortscale bass) are Ernie Ball 2837. Roundwounds.
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

thanks that's incredibly helpful
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Hans Bezemer
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Re: Baritone 12 string

Post by Hans Bezemer »

Starting with a 0.90 gauge string for the G will give you a reasonable tension.
If your building an (hollow) electric, then tension will be not that much of an issue.

I'm very interested in your project, because I'm thinking of building an 12 string baritone for a long time also.
I do use an other tuning (all fifths, starting with an low C (a fifths lower then your tuning)).

Does your plan already have more shape?
Do you want to have octaves for the first four strings and unison for the highest two?
What kind of body form are you after?

Hans
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

i'm currently leaning towards a modified Longhorn shape, i'm building the body, with Either maple sides and back and a spruce top, with a maple core centre, OR getting a little non-traditional with a foam and fiberglass layup body also with a maple centre. in either the top is spruce and braced like an acoustic ( the magnetics are secondary for this instrument, they are literally just so i canswell them in on some of the songs) i'll be doing octaves for the lowest four strings and unison for the highest pair
Freeman Keller
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Re: Baritone 12 string

Post by Freeman Keller »

At the 2008 GAL conference, D'Addario's Fan Tao gave a great presentation centered around selecting strings for some of the odd designs that luthiers are coming up with - bass guitars, long scale, odd tunings - which might apply here. His comments - first its pretty easy to run the formula and calculate the gauge of string (really, the unit weight) that will provide the tension you want at your chosen scale and tuning, but actually buying that string might be a whole different manner. D'Addario will do special runs of long and/or heavy gauge strings but it is wise to do this research first.

My own case is much simplier than yours - I built a 27 inch scale 12 string designed to be tuned A to A but it also has a tailpiece - finding strings that are long enough is possible (but barely). Leadbelly used something like 0.016 to 0.070, mine are a bit lighter, but the important thing is the tension is pretty close to a "normal" guitar.

Fan's advice is don't build yourself into a corner - do the calc's then see if you can actually buy a string in that gauge that is long enough. Then make sure you can find (or make) a bridge, pickups and all the bits and pieces and that your chosen string gauges will fit in the playable space (and that you can intonate them). Then build your guitar.

Finally, post some pictures and clips - I'd love to see it.

I'll add one other thought since you say that its to be braced like an acoustic - as long as your total string tension is somewhere in the 250 - 260 pound range contemporary acoustic bracing should be fine - my 27 inch "semi bari" is ladder braced like and old Stella, I have built other 12's designed for D to D tuning with three tone bars and 5/16 bracing. Note that if you are going to rely on magnetic pickups you can probably get by with much lighter strings and less tension, but of course you will sacrifice the acoustic sound.
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

Doing that exact kind of research, i found a couple ways around things (mixing guitar strings and Bajo Sexto, and/ or Bass VI strings namely) i think i am leaning away from the braced spruce top until i've made a few more standard electrics, and heading more towards routed tone chambers. i have little worry about making a bridge or a tail piece (the plan is to forge a wrought iron style frame for a purple heart tailpiece, mainly because i want to put some blacksmithing into the guitar) extending the upper strap horn a bit to help with balance, and building the body and neck in quartersawn sapele. The current design is starting to look a bit like a longhorn and prince's cloud guitar had a kid.. when i have full plans drawn up i'll post them
Freeman Keller
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Re: Baritone 12 string

Post by Freeman Keller »

Matthew, having read thru your specifications in the first and following posts I'm a bit confused by what you intend to build. You've posted in the solid/chambered electrical forum but you've also talked about building this as an acoustic. You really need to decide that before you go any farther for several reasons.

As you know, an acoustic makes it sound by the strings moving the top which moves air in and out of the body thru some hole(s). You choose string to furnish enough tension to drive the top without destroying it (and of course being able to fret them with some degree of ease). For an acoustic 12 string to work with common construction methods somewhere around 250 total pounds of tension, usually about 17 to 25 per string works pretty well. In addition, you need some sort of bridge that will drive that energy into the top either by rocking it or by a vertical component. Bridges can be pinned or not, but it must be designed to move the top. Obviously the top needs to be designed to move and braced accordingly. For most acoustics either some sort of piezo sensor in or under the saddle or glued to the soundboard works to amplify it. Microphones work to sense the movement of air in and out of the chamber. Most of the time the strings are made of a steel core wrapped by a copper alloy - some sort of bronze. The strings are not highly magnetic, the wrapping helps to color the sound.

Electrics usually work by moving strings made of magnetic material thru the field of the magnets in the pickups and inducing a signal into the coil. They require magnetic strings, often nickle. Next, because you don't have to drive the top the tension can be considerably less - 12 string electrics are typically around 200-210 pounds with maybe 15 to 20 per string.

Electric bridges can be very different from acoustics - the strings can be anchored to a stop bar, thru the body or to a vibrato. At least one manufacture (Braggs) makes a ToM style bridge with piezo crystals in it (I put one in my son's guitar and was totally unimpressed). The usual pickups, single coil or humbuckers require some structure to mount to - they can either float (like an archtop), have a small ladder brace (like an ES-175) or a big hunk of wood in the middle of the guitar (ES335). Point is, you can't just screw them to the top of an acoustic.

OK, so once you have decided which kind of guitar you are going to make (I think trying to combine them will compromise both) you need to think about the practical matters. You've selected your scale length and tuning and have a target for the tension in each string (acoustic or electric), you can either solve the basic formula for unit weight and see what gauge that turns out, or you can fiddle around with something like the Universal String Tension calculator. Now follow Tao's suggest an make sure you can actually buy that string - your 28.6 scale plus 2 or 4 or 6 inches at the tailpiece plus 8 or 10 inches at the headstock plus a few wraps on the tuner could easily give you strings longer than the 39 inches that most come in. If you are thinking of mixing them from other instruments just make sure that they have the same characteristics (and the ones you need)

Now that you have selected the strings there are a few other odd ball things about 12 strings to consider. If you are making an acoustic you'll need some sort of bridge that drives the top. If you pin it make sure that all the strings fit - pin heads frequently get in the way. Decide whether you want the primary or octaves closest to the saddle - you can do some ramping to make all of this work. Consider a very thick saddle so you have enough material to do a good job of compensation.

If you are going to do an electric, again, consider whether you can buy or build a saddle that will give you the spacing you want (both within a course and between courses), can handle the gauges that you've selected and that you can intonate. Decide how you are going to anchor them and how that fits structurally into the guitar.

The nut is somewhat simpler - most 12 strings are around 1-7/8 across the nut. Decide on your spacing (again, between courses and within each course) and whether the gauges that you've selected will allow this. Last concern at the head end is what you will use for tuners - most of us like some kind of mini tuner to keep the headstock from becoming unwieldy - will your string work with them or if you have bass strings will you need some huge bass tuners. Remember that you have wrap some sting on the post - if you have excessively phat strings can you do that.

None of the above is really affected by the scale or tuning (other than it leads you to your strings) but the longer neck on a bari can mean that you need to think carefully about where the neck meets the body (12, 14, 16, 19?) and where the bridge is located on the top. My experience is that 12 strings are very hard to intonate - it might not be realistic to expect to play way up the neck. Neck joint design is important - I have seen neck joint failures on two electric 12's (a Fender style bolt on and a short tenon set neck) and acoustic 12 are famous for having neck angle issues.

To put all of this in perspective - here are three of my 12 strings. On the left is my old Martin - short scale, can tune it to concert but I always tune it two steps down. Middle is a smaller bodied one, long Martin scale (25.4), always tuned down at least two semi tones. I usually put 10's on the first one, 12's on the middle. On the right is the long scale Stella-clone, not a true bari but I have tuned it every where from A to C with strings from 16 to 14. I frequently play it in some sort of open tuning - D or G down four or five steps. Its a monster slide guitar.

Image

The don't look that different but they are very different in construction, playability and sound. Good luck getting what you want with yours
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

Sorry for the confusion, it will in all but the most broad definition be an electric, about 1 3/4 deep, routed chambered body, it's serving as a more stage friendly alternative to an acoustic, going with the top built as if it were to be an acoustic instrument was more for a general tonal shaping before amplification. the project i play with has bagpipes, sometimes 2 sets of pipes going. my Bari jumbo at volumes high enough to be heard over 2 sets of pipes can be a horrific feedback monster, sowhat i will be going for is a Chambered electric that SOUNDS as close as possible to an acoustic, with magnetic pickups in a separate wiring harness for times when i need to up the intensity for the song... I've since pretty well ditched the concept of the acoustic style top, as i am not convinced it will be a significant contributor).

So in short, a bolt on neck, Baritone (28.5"scale) 12 string, chambered, piezo and magnetic pickup hybrid on separate harnesses. strung up to hit G1- A3 in a GDGDGA tuning, with octave strings on the lowest 4 courses. current plan is a wooden bridge with a bone saddle and a tailpiece sorry for any confusion...
Freeman Keller
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Re: Baritone 12 string

Post by Freeman Keller »

OK, thanks for that. Just one more consideration - think carefully about your neck joint. You say it will be a bolt on - I've seen one home made electric 12 string with a Fender style joint that was very weak (partially because he got the geometry wrong and had to do a lot of shimming to get the string plane correct).

And this little jewel is a cheap doubleneck - solid body, set neck, standard scale that came to me with a neck joint failure

Image

It had a massive headstock

Image

The way it was strung there was a resonable 210 pounds of tension, that should not have caused the failure. However it also was 19 frets clear and had a very short tenon, which was poorly made at the factory (it was loose from sided to side, had paint on some of the glue surfaces and really didn't have enough glue in the joint.

Image

The owner had dumped some 5 minute epoxy in the joint which promptly failed. I cleaned it all up, shimmed it so it was tight and reglued it with AR - as far as I know it is holding up fine.

Remember that your bari neck will be at least 1-1/2 to 2 inches longer so you will have even more of a lever at that joint. Just a heads up.
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

currently looking at 16 frets clear for that very reason, thanks for the tip, neck angle and stability of the neck is my biggest fear about this project, and the 28.5 scale is a lot of lever so the plan is not to be shy about how it attaches ( considering using 6 bolts) i don't play up the neck much at all in the project this is for so i'm not super worried about the heel being too bulky
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Beate Ritzert
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Re: Baritone 12 string

Post by Beate Ritzert »

Why is a standard 12 string neck not an option?

The standard scale of a Bass VI has a 30" scale. Its 3rd fret corresponds to the scale of a standard guitar. And that would mean a tuning of G-G... (or A-A or B-B in order to avoid the hassle with the too small tension .084" low string of the typical Bass VI set. These strings sound a lot more "guitar like" than "bass like".

I am aware that this would require custom strings. But at least Daddario offers single strings of up to 0.080, so designing the set should be pretty straightforward.
Freeman Keller
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Re: Baritone 12 string

Post by Freeman Keller »

One last thought and I'll shut up and let you build this thing. I happened to be in my local music store and knowing that they served the Mariachi bands in our Hispanic community I asked if they had a bajo sexto that I could look at. They said they didn't have one in stock but they had two bajo quintos, basically the same instrument but without the bass E course (it is a five course ten string instrument). It is interesting that the bridge resembles a classical gutar with a tie block but the strings have loop ends. They are passed thru a hole in the bridge then the loop is brought up over the tie block thingie and the string passed thru the loop. There is a fairly thick bone saddle. I asked the clerk where they got strings for them and he said D'Addario made sets for both the 12 string and 10 string bajos. The loop ends might work in a tailpiece similar to a mandolin but you might have difficulty mixing loop and ball ends

Both instruments had a magnetic sound hole pickup so the strings must have the magnetic characteristics required. Obviously they are also acoustic instruments. A quick check of D'Addario's web site shows that a bajo sexto has about 312 pounds of tension on the bridge - that is fairly high but the joint must be OK even without pins. It is also interesting that the 0.092 low E string has only 20 pounds of tension, less than the high F's. I don't know what the scale length is for either bajos (I could measure it on my next visit if you would like to know).

Lastly, the bajo quinto has a slotted headstock and apparently the string wrap just fine. Slot heads are pretty unusual on electric guitars (except Rick 12 strings) but then your whole instrument is going to be a bit unusual.

Thats enough from me, good luck with your project and please post pictures and sound clips. I really want to hear it with the pipes!
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

Beate Ritzert wrote:Why is a standard 12 string neck not an option?

The standard scale of a Bass VI has a 30" scale. Its 3rd fret corresponds to the scale of a standard guitar. And that would mean a tuning of G-G... (or A-A or B-B in order to avoid the hassle with the too small tension .084" low string of the typical Bass VI set. These strings sound a lot more "guitar like" than "bass like".

I am aware that this would require custom strings. But at least Daddario offers single strings of up to 0.080, so designing the set should be pretty straightforward.
i honestly had not really thought of that, i'm so used to playing long scale guitars that it just followed, but yeah i could go that route.
Matthew Orifice
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Re: Baritone 12 string

Post by Matthew Orifice »

Freeman Keller wrote:One last thought and I'll shut up and let you build this thing. I happened to be in my local music store and knowing that they served the Mariachi bands in our Hispanic community I asked if they had a bajo sexto that I could look at. They said they didn't have one in stock but they had two bajo quintos, basically the same instrument but without the bass E course (it is a five course ten string instrument). It is interesting that the bridge resembles a classical gutar with a tie block but the strings have loop ends. They are passed thru a hole in the bridge then the loop is brought up over the tie block thingie and the string passed thru the loop. There is a fairly thick bone saddle. I asked the clerk where they got strings for them and he said D'Addario made sets for both the 12 string and 10 string bajos. The loop ends might work in a tailpiece similar to a mandolin but you might have difficulty mixing loop and ball ends

Both instruments had a magnetic sound hole pickup so the strings must have the magnetic characteristics required. Obviously they are also acoustic instruments. A quick check of D'Addario's web site shows that a bajo sexto has about 312 pounds of tension on the bridge - that is fairly high but the joint must be OK even without pins. It is also interesting that the 0.092 low E string has only 20 pounds of tension, less than the high F's. I don't know what the scale length is for either bajos (I could measure it on my next visit if you would like to know).

Lastly, the bajo quinto has a slotted headstock and apparently the string wrap just fine. Slot heads are pretty unusual on electric guitars (except Rick 12 strings) but then your whole instrument is going to be a bit unusual.

Thats enough from me, good luck with your project and please post pictures and sound clips. I really want to hear it with the pipes!
did a little poke and Bajo's tend to be 25.5" scale which makes Beate's question make more sense to look at the shorter scale if for nothing more than decreasing the amount of leverage on the joint.

if you do a you tube search for Ashagal you'll hear where we are going with the general sound, though the pieces i specifically want the 12 for aren't recorded at all yet
Freeman Keller
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Re: Baritone 12 string

Post by Freeman Keller »

Matthew Orifice wrote: did a little poke and Bajo's tend to be 25.5" scale which makes Beate's question make more sense to look at the shorter scale if for nothing more than decreasing the amount of leverage on the joint.
If you solve the normal equation relating tension, frequency, vibrating length and "unit weight" (which is related to diameter and wrap) for UW you get

UW = (T x 386.4)/(2 x L x F)^2

(the term on the bottom is squared). That means that as the scale gets longer the unit weight or gauge of the string gets less by the square of the scale. You really need to solve the equation for a couple of your strings (probably the low G) with a couple of different scale lengths to see what gauge will be required (once you get UW you can look in D'Addario's chart to find what gauge that is).

As I said in my last post - the total tension on a bajo sexto seems to be well over 300 pounds - in my humble opinion that is a lot, particularly on a glued on bridge.

And back to the neck joint, I would sure consider putting inserts in the neck and making it a true bolt on rather than screw threads, maybe even a thru neck design?
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Barry Daniels
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Re: Baritone 12 string

Post by Barry Daniels »

This is probably why Bajo Sextos from Mexico are built so ruggedly. It may also be a reason why they fall apart after a year or two.
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