Martin String Length

[Bucc5207]

1/16" on a 25.4" scale corresponds to about 4 cents' difference in pitch, if I've done my math right. That's barely noticeable to a lot of people. It probably explains why one guitar sounds just slightly better intonated than the other.

[upsidedown]

I wouldn't know from which point at the saddle to measure, as it's angled - bass side lower than treble. I guess that's why the preferred method for measurement is nut to 12th fret doubled.

On the other hand, if the bridge where incorrectly placed, you'd never be able tell measuring it that way.

[Picker2]

Originally Posted by Bucc5207

1/16" on a 25.4" scale corresponds to about 4 cents' difference in pitch, if I've done my math right. That's barely noticeable to a lot of people. It probably explains why one guitar sounds just slightly better intonated than the other.

It's 0.2 per cents actually. Six percents is one step (a half tone), 0.2 per cents is negligible indeed.

[Victory Pete]

Originally Posted by Bucc5207

1/16" on a 25.4" scale corresponds to about 4 cents' difference in pitch, if I've done my math right. That's barely noticeable to a lot of people. It probably explains why one guitar sounds just slightly better intonated than the other.

Thanks, could you provide a link to this formula please?

[Victory Pete]

Originally Posted by upsidedown

I wouldn't know from which point at the saddle to measure, as it's angled - bass side lower than treble. I guess that's why the preferred method for measurement is nut to 12th fret doubled.

On the other hand, if the bridge where incorrectly placed, you'd never be able tell measuring it that way.

The theoretical 25.4" length would be for the smallest string as the smaller string would need the least compensation.

[Victory Pete]

Originally Posted by Picker2

It's 0.2 per cents actually. Negligible.

Are you sure it is not "2 cents"?

[charles Tauber]

Originally Posted by Picker2

It's 0.2 per cents actually. Negligible.

Then the math is wrong. Moving the breaking point of a "typical string" 1/16" one way or the other is an easily audible difference in intonation, in practice, rather than theory, often about 5 cents or more.

Given that both guitars are the same scale length, assuming the same strings are being used, tuned to the same pitch, with similar action, and assuming your measurements are accurate, more than likely, one or both guitars are not intonated "well". For "identical" scale length and setup, both should have the same vibrating string length, the distance from one end point (e.g. breaking point over the nut) to the other (breaking point over the saddle).

[Picker2]

Originally Posted by Victory Pete

Are you sure it is not "2 cents"?

Pitch (frequency) is inversely proportional to string length. Easy to remember: one octave (12th fret) is twice the frequency is half the string length.

So (1/16) / 25.4 = 0.00246 = 0,2 per cent longer string ≈ 0,2% lower frequency.

Could be any number of things. Martin has changed their saddle position and angle some over time. It's one of the "tells" for determining if a vintage bridge has been replaced. Not sure if they've made any changes since the late 90's or not. It could also be within their manufacturing tolerances, or just a mistake.

Another thing to remember is their advertised scale length is a nominal scale length and includes compensation. Of course, the length of each string is different due to the angle of the saddle. The actual scale length used for calculating fret spacing on modern long scale Martins is 25.340".

[Picker2]

Originally Posted by charles Tauber

Then the math is wrong. Moving the breaking point of a "typical string" 1/16" one way or the other is an easily audible difference in intonation, in practice, rather than theory, often about 5 cents or more.

I'm puzzled. Six per cents change in frequency is the distance between the nut and the first fret. That is much more than 1/16 of an inch, which then cannot be 5%.

[Bucc5207]

Originally Posted by Picker2

It's 0.2 per cents actually. Six percents is one step (a half tone), 0.2 per cents is negligible indeed.

1200*Log(25.4625/25.4) = 4.25.... cents (take the logarithm in base 2), or 3986*log(25.4625/25.4) (base 10 logarithm)?

A semitone is about 6% frequency difference, but there are 100 cents in a semitone.

[Victory Pete]

Originally Posted by Victory Pete

Are you sure it is not "2 cents"?

Originally Posted by Picker2

Pitch (frequency) is inversely proportional to string length. Easy to remember: one octave (12th fret) is twice the frequency is half the string length.

So (1/16) / 25.4 = 0.00246 = 0,2 per cent longer string ≈ 0,2% lower frequency.

Missed my point again, right over your head.

[Victory Pete]

Originally Posted by Todd Yates

Could be any number of things. Martin has changed their saddle position and angle some over time. It's one of the "tells" for determining if a vintage bridge has been replaced. Not sure if they've made any changes since the late 90's or not. It could also be within their manufacturing tolerances, or just a mistake.

Another thing to remember is their advertised scale length is a nominal scale length and includes compensation. Of course, the length of each string is different due to the angle of the saddle. The actual scale length used for calculating fret spacing on modern long scale Martins is 25.340".

Yes I saw that 25.34" number at Stew Mac. At LMI they say to calculate the saddle position but measuring to the 12 fret from the nut (I am assuming to the middle of the fret) double this and add 1/16th" and this is the edge of the saddle facing the neck. When I do this it corresponds to the D-42 saddle more accurately than the HD-28.

http://www.lmii.com/scale-length-intonation

[Picker2]

Originally Posted by Bucc5207

1200*Log(25.4625/25.4) = 4.25.... cents (take the logarithm in base 2), or 3986*log(25.4625/25.4) (base 10 logarithm)?

A semitone is about 6% frequency difference, but there are 100 cents in a semitone.

Aha, I see. You are talking musical 'cents' which I erroneously interpreted as percentage of frequency, which is what I always use. In that case we agree. Woohoo!

[Victory Pete]

According to Martin, they did make a change to the scale length. Apparently it is for the better because more of my new D-42 strings are intonated correctly.