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Spreadsheet for calculation of steel-string compensation
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Author:  Tim Mullin [ Wed Oct 21, 2015 7:18 pm ]
Post subject:  Spreadsheet for calculation of steel-string compensation

I'm currently building a fan-fret baritone guitar. One of the challenges is to calculate individual string compensation and where to locate the saddle(s). While there are some online calculators for this purpose, those I found are not "transparent", so hard to know exactly how they work.

I decided to create a spreadsheet for these calculations, based on the article by materials engineer Saajk Elmendorp (2010: American Lutherie 104: 56-60). Elmendorp presented his calculations in metric units, but some of the string engineering data are readily available only in US units (e.g., D'Addario Strings). Some fiddling was necessary, as well as some supplementary calculations of tension based on unit weight and tuned frequency. In the end, I declared input in metric or US, depending on what was most readily available to me -- you may wish to revise the sheet to your preferred input units.

I'm making the spreadsheet available for anyone who may find it useful. The spreadsheet is available here: http://www.mullinguitars.com/2015/10/compensation-calculator-for-steel-string-guitars.html (you'll have to unzip the file once you've downloaded it to your computer). You simply replace the input data given in the yellow-highlighted cells, and the sheet will recalculate automatically. The saddle compensation required for each string is given in the last column.

Of course I make no guarantees, so you will have to accept the risk if you use it for your own instrument design work. Happy to get feedback on the calculator, so let me know your experiences and suggestions.

BTW: I noticed that Typepad trashed the file on my website for my fret and fingerboard calculator -- it seems they no longer support Excel files unless they are distributed as zip files. For anyone who's interested, I've updated that post so that the calculator is again available at http://www.mullinguitars.com/calculating-guitar-fret-spacing-fingerboard-dimensions-and-string-setback.html

Author:  Ken Jones [ Thu Oct 22, 2015 4:34 pm ]
Post subject:  Re: Spreadsheet for calculation of steel-string compensation

This is very cool, Tim. Thanks for doing this. Fwiw, I made an FFBG awhile back and used the Stewmac fret spacing calculator for the two different scale lengths, then connected the dots. Worked beautifully -- intonation is dead on. The only caveat is that I had to make my own "saddlematic" based off the neutral fret, which in my case was the 7th. Worked like a charm.


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Author:  Tim Mullin [ Thu Oct 22, 2015 6:20 pm ]
Post subject:  Re: Spreadsheet for calculation of steel-string compensation

Ken Jones wrote:
I made an FFBG awhile back and used the Stewmac fret spacing calculator for the two different scale lengths, then connected the dots. Worked beautifully -- intonation is dead on.

The general lack of published values for typical baritone compensation is what got me into this research. I was somewhat surprised by the values I calculated and was hoping those with experience with baritone guitars would chime in -- thanks! If you look at my spreadsheet, you'll notice that compensation for the 1st, 3rd and 4th strings are around 4 mm, while that for the 2nd, 5th and 6th are closer to 8mm. Would be difficult to accommodate this on a single saddle. I found Motolla's online calculator gave the same values (once I found the appropriate units!) so I'm pretty sure the calculations solve the formulae correctly. Maybe the formulae are flawed?

Anyway, I'd like to hear from other baritone builders and their experience with compensation, as I'm on unfamiliar ground here!

Author:  Ken Jones [ Thu Oct 22, 2015 6:25 pm ]
Post subject:  Re: Spreadsheet for calculation of steel-string compensation

Here's a great video of Paul Heumiller discussing the baritone I made for him, with some good audio. http://youtu.be/0Zm-ufoGxuw


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Author:  Tim Mullin [ Fri Oct 23, 2015 10:04 pm ]
Post subject:  Re: Spreadsheet for calculation of steel-string compensation

Tim Mullin wrote:
Anyway, I'd like to hear from other baritone builders and their experience with compensation, as I'm on unfamiliar ground here!

Ken's comments and approach were interesting, but surely there are other builders on this forum with experience to share on compensation requirements for baritones?


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Author:  George L [ Sun Oct 25, 2015 3:08 pm ]
Post subject:  Re: Spreadsheet for calculation of steel-string compensation

No baritone experience to relate, but thanks for posting this, Tim. Much appreciated!

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