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12-string setup
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10101&t=55310		 Page 1 of 1
Author:  phavriluk [ Wed Oct 19, 2022 12:16 am ]
Post subject:  12-string setup
I had a working luthier install the bridge and nut on the first 12-string I made. It lived with my guitar teacher who liked to play it, and it was just sitting in the case with me. Fast forward to today, I tuned it up and commenced to prove that knew nothing about playing a 12-string. But I did notice that when I fretted between the 2nd and 3rd strings the strings lay down on the first fret....and the strings at the 12th fret were .140" off the frets.

Um.

Is there anything special about setting up a 12-string? Left to my own devices I'd raise the nut till the strings barely cleared the first fret when fretted between the 2nd and 3rd frets, and lower the saddle so the strings sit 3/32" (.093") above the 12th fret (bass E). I think these are in-the-game parameters. There is a huge amount of saddle exposed above the bridge and I'm not worrying about an underset neck. And I'll take a peek at the relief. Mr. Martin's doubleacting truss rod can handle any relief adjustments.

Reactions/advice/comments?

Thanks!
Author:  meddlingfool [ Wed Oct 19, 2022 2:11 am ]
Post subject:  Re: 12-string setup
There’s nothing I do differently with a 12 string other than to use a slightly lower action. I’d be shooting for 85-60Ee…
Author:  SteveSmith [ Wed Oct 19, 2022 6:02 am ]
Post subject:  Re: 12-string setup
First thing is to make sure the frets are level.


Steve
Author:  profchris [ Wed Oct 19, 2022 6:14 am ]
Post subject:  Re: 12-string setup
If it doesn't buzz when fretting at the first fret, then I'd leave the nut alone! If your luthier managed to go lower than the strings just barely clearing fret 1 when you fret between 2 and 3, well done that luthier - you want the nut as low as possible without buzzing.

I'd start by setting the relief, and then decide what I wanted the action at the 12th to be. Once that is set, if all frets play cleanly I'd be done. If not, I'd track down and correct irregularities, re-set relief, adjust action at the 12th, and be finished.

However, it would be worth checking the lower frets for buzzing after each change (relief, 12th fret action) in case they render the nut too low. In which case, raise the nut slightly (shim probably) and carry on.
Author:  Hesh [ Wed Oct 19, 2022 6:33 am ]
Post subject:  Re: 12-string setup
When you fret and hold between the 2nd and 3rd and if there is no gap under the string at the 1st fret crown that string likely will buzz open and if it doesn't hit it harder it likely will buzz it's too low.

String laying on the first fret when fretting and holding between the 2nd and 3rd is too low and the nut slot needs to come up. Unless it's had a LOT of use and if this is a bone nut the slots may be cut too low and it may be more than one of them. Nut shimming, new nut.... or light cured dental fillings are some possible options for you.

Get the nut in shape first and all you need are strings, tuned to pitch, truss rod adjusted and good eyes and files. Once the nut slots are cool then and only then do you go to the 12th and see what you have measurement wise.

For everyone else if you have not spent any times perfecting cutting very low nut slots a 12 will not be your friend. They are critical to have the nut near perfect or player fatigue becomes the reason once again we see people only owning them a few years and then tossing them to Reverb....

I set 12's just like a 6 string only a bit lower. So once the nut slots are perfect and taken out of play and the truss rod has relief where I want it I seek <4/64" on the high e (either of them...) at the 12th and around 4/64th" for the low e (both of them...) also at the 12th. Of course both strings in a course if the same gauge should be the same height.

!2's are supposed to be a bit janglly with a bit of fret noise and you can hear this in any number of famous 12 recordings such as Hotel California or Tom Petty RIP stuff. Otherwise they are too difficult to play if the action is not uber low.

As mentioned good fret work is critical on a 12 because the action is slightly lower than a 6.

So first truss rod, nut slots, measure at the 12 and mill saddle to get where you want to go at the 12th. All this is done strung to pitch with the exactly strings that you plan on using going forward.
Author:  phavriluk [ Wed Oct 19, 2022 8:49 am ]
Post subject:  Re: 12-string setup
Thanks everybody!

I think I had the right impulses, save the order of operation: relief first. My guess was that the way-too-high action was masking the too-low string slots in the nut. Now the big effort will be in committing the needed patience to the project.
Author:  jfmckenna [ Wed Oct 19, 2022 8:56 am ]
Post subject:  Re: 12-string setup
I have seen guitars 'get away with' nut slots that are too low if the action is too high at the saddle. .14 as you mentioned is way too high at the 12th fret. So yeah your thinking is right to me. Raise the nut and cut it properly, set the relief and lower the saddle.
Author:  Hesh [ Wed Oct 19, 2022 9:08 am ]
Post subject:  Re: 12-string setup
jfmckenna wrote:
I have seen guitars 'get away with' nut slots that are too low if the action is too high at the saddle. .14 as you mentioned is way too high at the 12th fret. So yeah your thinking is right to me. Raise the nut and cut it properly, set the relief and lower the saddle.


It's string dependent too. A .012 will arc perhaps .001 - .002 out of the slot and this is how it's possible to cut a nut slot below the height of the first fret and not have it buzz.

Peter yep too much relief and too high action will mask too low nut slots. That's why we always adjust the truss rod after turning to pitch and then I tune to pitch again and then do the nut slots. The beauty of what I offered to you above is it's sequential with the benefit being if you tune to pitch, adjust the rod, tune a final time and then cut the slots you never have to revisit the nut again and can more on in the set-up to the things that are a function to some degree of the nut slots.

A very useful thing to demonstrate to people learning this stuff is to add a bit too much relief and then cut the slots. Now reduce relief to where it should be and some of your slots may be too low. This is exactly what Peter observed but in reverse. It's also true that if you cut a slot a hair too low sometimes adding more relief if no one is looking... :) make the nut slot perfect... ;)
Author:  Freeman [ Wed Oct 19, 2022 10:44 am ]
Post subject:  Re: 12-string setup
phavriluk wrote:
Thanks everybody!

I think I had the right impulses, save the order of operation: relief first. My guess was that the way-too-high action was masking the too-low string slots in the nut. Now the big effort will be in committing the needed patience to the project.


I'm late to the part but will chime in anyway. I set up a twelve string basically the same way I do a sixer. First I select strings and tunings that will put the total tension somewhere around 225 pounds, more that an six but not excessive. Level the frets perfectly, about 0.005 relief, nut action 0.012 to 0.016 or so. 12th fret action at 0.060 to 0.090. I have one twelve that I play a lot of slide on, it gets a little higher but not excessive. I also try to make the nut slots the same depth for both strings of the course, that is the same first fret clearance.

One thing to remember is that many older 12 strings have pretty bad neck angles and may have bridge issues - both which I deal with before doing the actual setup.
Author:  phavriluk [ Thu Oct 20, 2022 1:54 pm ]
Post subject:  Re: 12-string setup
This 12 is shiny new from my bench, so at least whatever age-related workarounds might be needed for a 'mature' instrument minimally apply. Lord knows I've got enough quality time scheduled to finish setting this one up.
Author:  Pmaj7 [ Thu Oct 20, 2022 2:18 pm ]
Post subject:  Re: 12-string setup
All really good advice here! And Hesh even raising the bar. (or should I say lowering? Lol)

Only thing to add is to confirm you are doing the tink test on the e&b?

Pat
Author:  Hesh [ Fri Oct 21, 2022 2:50 am ]
Post subject:  Re: 12-string setup
Pmaj7 wrote:
All really good advice here! And Hesh even raising the bar. (or should I say lowering? Lol)

Only thing to add is to confirm you are doing the tink test on the e&b?

Pat


Yep the "tink test" (I like that :) ) still is in play and necessary. I find these 12 strings the e and b very hard to see these days too and I mean when cutting the nut slots. I have to put on 2.5 magnifiers to see the sucker.....

Pat the North Star for a successful 12 set-up is an understanding that they are nearly twice as hard to play as a 6 string so the set-up, fret work, etc all have to be pretty good or it will end up just another 12 that no one wanted.....
Author:  Freeman [ Fri Oct 21, 2022 3:01 pm ]
Post subject:  Re: 12-string setup
Hesh wrote:
Pat the North Star for a successful 12 set-up is an understanding that they are nearly twice as hard to play as a 6 string so the set-up, fret work, etc all have to be pretty good or it will end up just another 12 that no one wanted.....


I firmly believe that with the proper strings and setup a 12 string should not be that much more difficult to play than a sixer.

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