12-String Tuning Issue - Danelectro

[akpasta]

Okay Freeman, here we go. I've taken photos as best I can (this is hard) of the tuning readings of the low G string, a .017" string, the same gauge that the guitar came with, starting with open G, then every fret all the way to the 12th fret. As you can see, the open string is in tune at G, and it is sharp on every fret until the 7th fret, when it is in tune again at D, and is then more or less in tune up to the 12th fret. Trust the "in-tune" readings, the tuner jumps around a little before I can get a photo snapped. The sharp readings are accurate.

 

Follow the link to the photos which are labeled. https://drive.google.com/open?id=0B37sRqu6aK-OLTVXNDg4WDh1ZEk

 

Now what?

[Freeman Keller]

That is what I wanted to see, thank you. And confirm that you don't see it on the little G or any other string, and that the 0.017 is a plain (unwound). Mean time, let me do some research.

[akpasta]

Confirm. Only this string has this problem and it is a flat unwound string.

[Freeman Keller]

OK, I'm going to give a very quick explanation of what i think is going on - I need to be at a function shortly and won't have time to get back to this until Sunday night. What you are observing is a problem with EVERY guitar, not just your 12 string and results from four different things all working together. They are

 

- our equally tempered music system which spaces our 12 notes equally based on a mathmatical formula (12th root of two or so called "Rule of 18"). It is by definition a compromise and results in some notes being slightly out of tune with others

 

- the fact that guitar strings have "stiffness" which is not usually taken into account in the math formulas. Stiffness is associated with the diameter of the string (core wire of a wound string) and makes the partials of the note play sharp. One way to think about it is at the fret the first little bit of string doesn't start vibrating exactly at the string, its a little ways away, which makes it sharp. A 0.017 is about as large an unwound string as we usually use, therefore it is the stiffest. The octave G is probably about an 0.008 or 9 and is far less stiff.

 

- height and width of frets and fretting finger pressure all contribute to the amount a string is stretched (bent) when fretted which increases its pitch. It shouldn't matter which string is being fretted but it does

 

- our method of "compensating" or "intonating" a string is a compromise. By setting the 12th fret note equal to the harmonic we assume that it averages out over the fretboard, what it really does is makes it better where we typically play. It is also really easy LOL. A much better way is to compensate at both ends, meaning that the nut will also need to be moved. Remember that compensation at either end depends on the strings, if you change gauge you really need to re-do it.

 

To test some of this I took my LP out to the shop last night. It has and 0.017 unwound third. Its action is very low and the 12th fret compensation is dead on. I fretted each fret as lightly as I could and checked the notes with a strobe tuner. Just like your example, my 1st fret was 3-4 cents sharp, 2nd was about 3 cents and on up to the 7th which was less than one. So it is not a problem with your guitar as a 12 string but I'm guessing that the octave string sharpens less so you are really aware of it. Frankly I can't hear 3 or 4 cents but my little Peterson tuner sure can.

 

OK, what can you do? Moving frets is not practical and compensating the nut would be a heck of a hassle on a 6 string, much less a 12. You can try to minimize the stretching - get the nut action as low as possible, minimize the relief, and as your tech told you, low frets would be better (but again, not too practical). Probably the best thing is to flatten you G string when you tune it, however that compromises any chord with an an open G. The other thing, as Badpengin suggested is to simply accept that as one of the characteristic 12 string sounds.

 

I'll add that I'm an acoustic 12 string player and have been aware of this for a long time but never really thought about why. Most of us tune our guitars 2 steps lower (D to D) for less tension and a different sound, and we put a capo on the 2nd fret when we want to play with others or sing. Almost all of us automatically retune, usually the G course, when we put the capo on.

 

If you would like to read some scholarly articles on all of these subjects I can give you links but this is about all I have time for now. Hope it helps

[akpasta]

Thank you Freeman for confirming what the guitar tech told me.

 

I currently have found a somewhat happy medium in terms of tuning that string slightly flat and will just live with it.

[jonj3]

I also have a Danelectro 12-string. Here's a tip that might help: tune the guitar down 1/2 step and put a capo on fret #1. The use of the capo seems to help with the intonation problem. Try it! HELP! I just pulled my Danelectro 12-str out of the closet after about a year. I had loosened all the strings to lower the tension. But when I started to tune the strings, I notice many of the strings are actually touching the frets, even as I use the tuners to tighten them. What could have happened? I don't see a noticeable bow in the neck. Any ideas where to start?

[Grant Harding]

[WRGKMC]

If the bridge is compensated, and the relief is correct and you're still getting the string bending sharp, then try a different brand or gauge of strings.

Different manufacturers use different types of steel and core sizes and they can make a dramatic difference in how well and instrument intonates.

 

If the guitar was bought used then you may have an issue with fret wear. If the frets were leveled at some point to remove grooves in the frets they may have taker the lower frets down more then the upper frets which increases the distance to the strings and makes them bend sharp. If the fretboard is flat that's as far as you can safely use relief to correct the problem. If you back bow the neck to make the frets level then you'll have all kinds of tuning and fret buzz issues.

 

Also, if the frets were leveled, you typically have to lower the bridge by as much as you take the frets down too. Leveling also makes the frets flat on top and the breakaway point on the fret winds up being closer to the bridge instead of in the center of the fret. Frets need to be crowned to get the contact point in the center of the fret instead of the edge.

 

12 string necks on electric often have issues of bowing and twisting too due to all that added string tension. If the problem isn't too bad, you could pull the frets and relevel the fret board. If the instrument has been neglected for a long time tweaking the truss can take several months for the wood to acclimate to the changes in tension.

 

One thing you can try is tune the strings down one whole step. I used to do that with my 12 strings and I got much longer lifespans out of the instrument with the reduced tensions. Again, try changing string types first. These Labella strings https://www.juststrings.com/lab-hrs-12.html are some of the best gauged and tensioned string on the market. If you still have problems, its definitely something else structurally or setup wise causing your problems

[jbreher]

You're not crazy. Some 12-strings just do this. I've not been able to figure out exactly why, but they do. Those talking about (12th fret) intonation settings, and/or equal temperament issues are missing the point.

 

Ex: My Fender Stratocaster XII. Perfectly intonated at 12th fret. No evident nut issues. frets properly* placed, as evidenced by removing the upper course strings.

 

*i.e., equally tempered, reflecting the best possible compromise for use in multiple keys.

 

The only problem I see is that, after tuning the two G's at the open nut position, most notes on the G string have both G's in tune -- with the exception of 'cowboy chord' position. Most egregious on the A note. The two strings are cringe-ing-ly off from each other there. The G# on 1st fret hides almost well enough in an open E chord, and it's pretty much in tune from the B note on the G string on up. But the A drives me batty. Had it to a couple of luthiers, at least one with a national reputation. No love. It's just the way it is.

 

WRGKMC is on track (in 1st observation, though other suggestions have been tried and ruled out), in that it can be minimized by choice of strings. Still, however, quite evident with any I have tried. I own other 12-strings that don't exhibit this issue, and have played many more. I was almost thinking I was crazy until I saw your post.

 

Yeah, if I could cut the frets so that I can reposition just that under the lower G, it would fix the issue. Though that would bring its own host of problems.