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Old 05-16-2022, 01:55 PM
RJVB RJVB is offline
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Default compensated saddles - single straight vs "zigzag" vs. 2x straight

I've become curious to know a bit more about compensation at the saddle.

I know that some acoustic flattops have 2 straight saddles, 1 for IIRC the plain wire E and B strings and another one for the wound strings. They're roughly parallel but with a "reset" for the wound G string, looking a bit like a flash seen from above. All other flattops I've seen have a similar pattern cut out in a single saddle.

Assuming that the vast majority of players use a wound G I concluded that this pattern must best represent the average amount of compensation required for sets with only 2 plain wire trebles used in standard tuning. It also seems logical: if the B needs more compensation than the high E, a plain wire G would probably require even more, but a wound G is a completely different animal and might require less (and then subtly more for each of the lower wound strings.

I'm thus surprised to see that many archtops use a single straight (but oblique) saddle, and in a discussion elsewhere it was suggested that a plain wire G will not intonate correctly with a straight saddle.

So apparently something is wrong in my reasoning above, but what? And which design gives the most accurate intonation with "normal" sets (with a wound G), in the end?
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Last edited by RJVB; 05-16-2022 at 01:59 PM. Reason: straight doesn't imply orthogonal to all strings!
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Old 05-16-2022, 03:18 PM
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rick-slo rick-slo is offline
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Saddle recession helps to compensate for string stiffness and that stiffness comes more from the core string diameter than the windings (hence the typical 2nd string being more recessed than the 3rd string). Classical guitars generally have a straight saddle as string stiffness of nylon is much less than steel.

That is the aim anyway though different saddle contours are out there with more or less success in taming intonation issues.
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Old 05-16-2022, 03:35 PM
Alan Carruth Alan Carruth is offline
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rick-slo wrotes:
"Saddle recession helps to compensate for string stiffness..."

This is a matter of some discussion. Gore's intonation model was based on the differences in the way the tension changes as the string is depressed. If you can accept his math he showed that the stiffness model is not a very good fit to what happens with strings. As always, there is no 'perfect' model, and I don't think anybody will argue that stiffness can't have an effect, it just doesn't seem to be the major one.

One fly in the ointment is that the guitar itself can affect the amount of compensation needed. Vibration of the top can 'feed back' into the string and alter it's pitch. This is usually only noticeable on very responsive instruments, and normally only in the lower range, but it can make a difference if you're looking for the best possible intonation.

It's also necessary to keep 'intonation' and 'temperament' straight. It's mathematically impossible to construct a scale that will sound good for all keys, so musicians have to compromise ('temper' the scale) shifting the pitches of notes depending on the circumstances. Guitars default to 12-tone Equal Temperament, in which all of the semitones are musically the same size (so the frets are straight), and every major key is equally 'out' in the same way (so you can modulate freely). Intonation is set up to produce the 'correct' pitches for that temperament, but once you start to hear the problems (major thirds are 'off' by a lot!) they never go away.
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Old 05-16-2022, 03:36 PM
RJVB RJVB is offline
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I see I forgot to clarify that I know why compensation is required (and also that a guitar with a standard fretboard can only be in tune as far as equal temperament allows).
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Old 05-16-2022, 03:41 PM
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Quote:
Originally Posted by Alan Carruth View Post
rick-slo wrotes:
"Saddle recession helps to compensate for string stiffness..."

This is a matter of some discussion. Gore's intonation model was based on the differences in the way the tension changes as the string is depressed. If you can accept his math he showed that the stiffness model is not a very good fit to what happens with strings. As always, there is no 'perfect' model, and I don't think anybody will argue that stiffness can't have an effect, it just doesn't seem to be the major one.
String stiffness well established as leading to the need for various compensations (as I pointed out in steel versus nylon strings). Naturally
other factors in play.
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Old 05-16-2022, 03:48 PM
RJVB RJVB is offline
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Quote:
Originally Posted by Alan Carruth View Post
but once you start to hear the problems (major thirds are 'off' by a lot!) they never go away.
There is something physiologically different (more pleasant) to just intervals, as a singer once told me. I can confirm (and that even a well tempered fifth doesn't sound right; major thirds actually hurt).

This, and movable (and splittable!) frets on lutes and viols is what gave us the prélude: préluder in fact refers to a player "doodling" in the key of the composition he's about to play, adjusting the tuning of his open strings and nudging frets to get the best possible intonation.

Fortunately for me you can also learn to accept the compromise tuning ('muddy your ears' ). To the extent that I find it much more tolerable to play on new strings that haven't stabilised yet on guitar than I found it on violin.
(This does however NOT apply to a badly tuned guitar played by someone else )
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Old 05-16-2022, 03:49 PM
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Quote:
Originally Posted by RJVB View Post
I'm thus surprised to see that many archtops use a single straight (but oblique) saddle, and in a discussion elsewhere it was suggested that a plain wire G will not intonate correctly with a straight saddle.
Many archtops do have G string compensated saddles similar to flattops and many flattops have straight saddles. Does not mean that is the best way to go.
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Old 05-16-2022, 04:05 PM
RJVB RJVB is offline
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Quote:
Originally Posted by rick-slo View Post
String stiffness well established as leading to the need for various compensations (as I pointed out in steel versus nylon strings). Naturally
other factors in play.
We'd have to be careful what stiffness is meant here. You seem to be referring to elasticity/stretchyness but there's also the ease with which a string will bend.

The layman's explanation of why compensation is needed is that the string tension increases when you push down the string, causing pitch to rise. With nylon strings this is largely compensated by the fact that the material stretches and thus becomes thinner (because of this nylon strings also always stabilise at a lower tension than the calculated theoretical value based on their unloaded properties).

Observation: I'm currently using Pyramid Tape Nylon wounds, e-guitar strings that have a (black) nylon. tape winding over very thin wound steel strings. These are known to be very sensitive to fretting too hard (they go noticeably sharp) but the D and E also require significantly more compensation (the low E is in fact unusable because of this). I'm pretty certain they are as non-stretchy as any other steel string so it's almost certainly not that stiffness which explains there greater need for comensation.
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Pickle: Gretsch G9240 "Alligator" wood-body resonator wearing nylguts (China, 2018?)
Toon: Eastman Cabaret JB (China, 2022)
Stanley: The Loar LH-650 (China, 2017)
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  #9  
Old 05-16-2022, 04:05 PM
Robin, Wales Robin, Wales is offline
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After messing around with saddles on a very small sample size of 4 guitars, I liked the bog standard old fashioned slightly offset non compensated saddle with a rounded top the best.

They are very easy to shape from a squared blank; you can shape them from the top or bottom to dial in your final height; they intonate just fine; and, most importantly the top shape actually effects the timbre, particularly of the treble strings, in a good way.

This last point was an accidental finding. Many compensated saddles set the b and e strings on narrow ledges to either the back or front of the saddle for the purpose of "intonation". By bringing the strings release point to the round topped middle of the saddle it seems to me to mellow out the b and e strings and strengthen their tone.

I have seen lots of information about cutting saddle tops for intonation, but strangely nothing on the effect the saddle top profile has on tone?

Regarding archtops: I quite like the fact that I can slide the bridge around to intonate my archtop; and far prefer to trust my ears when doing so rather than any tuner!!!
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Old 05-16-2022, 04:19 PM
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Quote:
Originally Posted by RJVB View Post
We'd have to be careful what stiffness is meant here. You seem to be referring to elasticity/stretchyness but there's also the ease with which a string will bend.
When I am using the word stiffness I am talking about a string's resistance to bending and not elasticity. Why that matters in part as far as setting up a guitar's compensation is the effect of stiffness on the amount of a string's inharmonicity. For prior threads here on the topic you could do a forum search. As far as string length changes on fretting, if you use a light touch to get to the fret top (and not mashing the string down further towards to the fretboard) the string length change is a few thousands of an inch (ala Pythagoras).
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"Reality is that which when you stop believing in it, doesn't go away."

Woods hands pick by eye and ear
Made to one with pride and love
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Last edited by rick-slo; 05-16-2022 at 08:27 PM.
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  #11  
Old 05-29-2022, 07:20 AM
endpin endpin is offline
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I have been following a YOUTUBE channel called "STRINGTECH WORKSTATIONS” where he puts compensated nuts on various guitars.

The unique thing about his channel is he PLAYS each guitar after the nut is modified to demonstrate the improvement of chords.

He does, however, favor certain chords with intervals that show the results of his modifications to best advantage.
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  #12  
Old 05-29-2022, 08:47 AM
RJVB RJVB is offline
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Favouring certain chords is fine; it wouldn't make sense to pick chords with intervals that are more audibly "off" because of the equally tempered temperament - if those sound better that's not an indication that the saddle's general-purpose compensation is better than some other saddle's!

Is there a video that has an overview of the conclusions?
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Pickle: Gretsch G9240 "Alligator" wood-body resonator wearing nylguts (China, 2018?)
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Stanley: The Loar LH-650 (China, 2017)
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