The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Reply
 
Thread Tools
  #1  
Old 03-14-2019, 01:59 PM
packocrayons packocrayons is offline
Registered User
 
Join Date: Jan 2017
Posts: 71
Default Multiscale 12 string - scale length for octave strings

On a fan-fret 12 string, since there is a gap between the octave and root (6 string equivalent) string, a nut that is angled will give a different scale length to these strings.

Of course, if the strings are a straight run, they will intonate fine as the fret spacing is relative to scale length across the whole fretboard.

However, what I've noticed when playing a 12 string is that the strings tend to join together when pressed. In this case, I could argue that the nut/saddle should be 6 straight pieces instead of one solid angled piece.

What's the consensus here? I know given the spacing and the angles of the saddle, the intonation in either way will be very close. 6 individual pieces allows for 12 independent compensation points, which some may argue is necessary since the string gauges are so vastly different in a 12 string.

Looks like there are very few of these beasts out there in the wild, so at this point theory is likely the limit of this discussion.
Reply With Quote
  #2  
Old 03-16-2019, 03:32 PM
Mark Hatcher's Avatar
Mark Hatcher Mark Hatcher is offline
AGF Sponsor
 
Join Date: Jul 2011
Location: Peterborough, New Hampshire
Posts: 3,097
Default

Congratulations! This is a question I don't think has ever been asked on any of the AGF forums before.
It has not been my experience that the strings are pulled together when fretted on a 12 string but, I suppose that is a player issue. However, I do like the idea of creating flat areas for intonation purposes particularly when there is a large spread of scales in the fan.
Here is are pictures of 1 1/2" spread fan fret guitars I recently made where I created what I called a sawed tooth saddle which provided those flat areas:





It would not be an issue to do a similar set up to intonate each of the 12 strings to your liking. Personally, I only start with theory and then make my best guess dummy saddles out of wood until I get the intonation right and then copy that in bone.
__________________
Mark Hatcher
www.hatcherguitars.com

My new website is up!
Try it out.
Reply With Quote
  #3  
Old 03-18-2019, 09:55 AM
packocrayons packocrayons is offline
Registered User
 
Join Date: Jan 2017
Posts: 71
Default

Thank you for the input.

I think the plan is going to be a single piece, angled nut and 6 individual saddles. I am confident I'll have enough room to intonate the saddles for each string, after basic compensation calculations.

I'll definitely have a pile of test saddles for kindling by the time I'm done
Reply With Quote
  #4  
Old 03-18-2019, 06:45 PM
Bruce Sexauer's Avatar
Bruce Sexauer Bruce Sexauer is offline
AGF Sponsor
 
Join Date: Jan 2009
Location: Petaluma, CA, USA
Posts: 5,731
Default

I say you're over-thinking it (both of you). If you make the saddle look normal (whatever ramping and intonation system you believe works), I believe there is no more issue because of multiscale than there would be with monoscale, all of the geometry takes care of itself. A string has to get quite out of line with its intend path before pretty much anyone can discern an extraordinary intonation issue. Since no guitar is actually perfect, and if it were no player has perfect technique, getting very close is all we can really do. I use exactly the same intonation correction concept and math on my multiscale as I do on my monoscale guitars. That said, I have never heard a 12 string that I thought as close to being in tune up and down the neck as a well thought out 6 string. That's part of their charm, in my mind.
__________________
Bruce
http://www.sexauerluthier.com/
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Thread Tools



All times are GMT -6. The time now is 10:59 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2000 - 2018, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=