String gauge and intonation

Dwain Wilder
Dwain Wilder
one month ago
58 posts


Hi Nate,

You describe a common problem. And different string makers use different core diameters (and some use hexagonal core wire, so it bites into the winding for improved performance. And I too sometimes find that in a tuning such as DDAd I have to compensate the A string at the nut. Curiously, this is not on every instrument.

And I find that choosing string sets that operate at equal/similar tensions minimizes compensation of the saddle, as well as producing brilliance in each string that is in a similar 'brilliance envelope', so that playing a scale across all the strings does not sound different from playing the same scale on a single string.

I have a spreadsheet that computes string tension for sets of strings, given their operating pitch, string diameter and whether plain or wound. It turns out that the the fudge factor "k" needed to compute the tension of wound strings is very similar for most of the strings I've encountered (GHS, DR, etc.), so an average can be used for a given manufacturers' strings.

PM me if you'd like me to email the spreadsheet. Requires MS Excel. At present I can only supply it in Mac 64-bit word (Catalina OS and higher), but soon will have it available in the more widely used 32-bit word version. Either one should work in a PC Windows environment also...

one month ago
244 posts

Hey folks I was hoping to get some clarification about how string gauge affects intonation. I have noticed that an unwound middle string needs to be compensated about 1/16th of an inch longer than a wound middle string. If I don't compensate the middle slot differently than the others, it can often be up to 15 cents sharp at the octave, when properly tuned.
I remember hearing in passing a long time ago that wound strings need to be intonated to compensate for their core diameter and not their wound diameter. Can anyone verify this?

And if so, does anyone know what size core corresponds to certain gauges of wound string? For example, what is the core gauge of a .18 and a .24 string that are wound? Maybe I can use the digital calipers at my work and measure some cores.

I have noticed that in order to correctly compensate for my middle strings, the bridge needs to be shaped differently depending on whether the string is wound or not. Is this a common issue? and is there a better solution than just having two separate bridges with the two different compensations?

Thanks for any info, and sorry if the questions aren't asked very clearly,


updated by @nate: 03/05/24 12:41:54PM