Question about saddle position and intonation

bunkaroo · #1 11-30-2011, 07:59 PM

I'll start by saying I've read through a lot of threads here I understand how to intonate now, but just to confirm, this is what I am doing:

-Tune the open string to pitch
-Check the 12th fret harmonic
-Fret the 12th fret (lightly)

If the 12th fret is sharp, loosen the screw (CCW) to lengthen the string. Retune the open string and repeat the steps.

So I got a new Stingray 5 today and the neck and string height look and feel great. I've had my other SR5 setup professionally and they feel just about the same (strings are a bit heavier on my other SR5).

I've got the intonation nailed down pretty good on this new bass, but I had to bring the G string saddle back a decent amount to get it in tune, a decent amount behind the next saddle. The 12th fret was a good few ticks sharp when I started.

I'm used to seeing the G string saddle sitting closest to the neck out of all of them strings, and the lower the string, the farther back. None of my other basses have a G string saddle farther back than the D string saddle.

Here's a not so close up pic to illustrate:

Does this point to a bad string? The string is factory wrapped 3 times around the tuner so I don't think it's slipping.

Any info or links are appreciated.

walterw · #2 11-30-2011, 08:59 PM

no, it looks like you're actually good.

the G usually has a single layer of wrapping, while the rest of the strings have 2 or more.

this difference in tension and flexibility creates the "jog" between the G and the D, just like the transition from plain strings to wound strings on guitars creates a jog, where the fattest plain string needs to be a little longer than the thinnest wound string.

also, the 12th-fret harmonic is irrelevant to these pursuits; you check the open string with the fretted notes.

bunkaroo · #3 11-30-2011, 09:14 PM

Ok thanks. Just seemed strange to me given my other SR5 is spot on intonation wise and has the G saddle closer to the neck, perhaps it's the difference between D'Addarios on that one vs. the Slinkies on the new one.

Slowgypsy · #4 12-01-2011, 04:18 AM

Different brand strings, and different gauge strings can have an effect on intonation. Even a different set of the same brand and gauge of string can have a small effect. That's why checking intonation with every string change is a good habit to get into. It's such a simple, easy to do process.

georgestrings · #5 12-01-2011, 07:14 AM

Quote:

Originally Posted by walterw

also, the 12th-fret harmonic is irrelevant to these pursuits; you check the open string with the fretted notes.

This contradicts anything I've ever read on the subject, including several highly regarded books... I've always read/been told that you check the 12th fret harmonic against a fretted note at the 12th...

- georgestrings

ddnidd1 · #6 12-01-2011, 08:39 AM

"If the 12th fret is sharp, loosen the screw (CCW) to lengthen the string. Retune the open string and repeat the steps."

You would want to turn the adjusting screw clockwise to lengthen the string.

Turnaround · #7 12-01-2011, 08:47 AM

Quote:

Originally Posted by georgestrings

This contradicts anything I've ever read on the subject, including several highly regarded books... I've always read/been told that you check the 12th fret harmonic against a fretted note at the 12th...

- georgestrings

You are both right. Point is, if the open string is in tune, the twelfth fret harmonic will also be in tune - it has to be. So you can tune open then check the fretted note, or tune the harmonic and check the fretted note. Pointless to tune the open string then check the harmonic.

Slowgypsy · #8 12-01-2011, 09:43 AM

I think the harmonic to the fretted note is suggested because they are both the same octave, so perhaps it's easier to hear any difference in pitch. Also, some folks find hitting the harmonic and fretting the note somehow easier as your fretting hand is already in position. But in my experience, the harmonic and the open note are really the same thing, so they have to agree with one another. I'm sure there's some physics reason why that's not so, but in the real world either open note or harmonic to fretted note works.

bunkaroo · #9 12-01-2011, 09:51 AM

Quote:

Originally Posted by ddnidd1

"If the 12th fret is sharp, loosen the screw (CCW) to lengthen the string. Retune the open string and repeat the steps."

You would want to turn the adjusting screw clockwise to lengthen the string.

That's right I mixed that up typing it out. That's what I was doing.

georgestrings · #10 12-01-2011, 03:18 PM

Quote:

Originally Posted by Slowgypsy

I think the harmonic to the fretted note is suggested because they are both the same octave, so perhaps it's easier to hear any difference in pitch. Also, some folks find hitting the harmonic and fretting the note somehow easier as your fretting hand is already in position. But in my experience, the harmonic and the open note are really the same thing, so they have to agree with one another. I'm sure there's some physics reason why that's not so, but in the real world either open note or harmonic to fretted note works.

Just a guess, but the harmonic *might* read a little more accurately than an open note - I'm guessing that because some tuners that don't track well with low notes(B, C, etc...) will usually track better with the 12th fret harmonic...

Not only that, but I suppose it's possible that if the intonation is actually off, the open note and 12th fret harmonic actually may not "agree" with one another...

- georgestrings

mikezimmerman · #11 12-01-2011, 03:31 PM

Quote:

Originally Posted by georgestrings

Not only that, but I suppose it's possible that if the intonation is actually off, the open note and 12th fret harmonic actually may not "agree" with one another...

- georgestrings

Nope, that part isn't possible. The "12th fret harmonic" is actually the "half string harmonic". If the bass is really badly intonated, what will happen is that this harmonic will not be above the 12th fret, but it will still be an octave above the open string.

Mike

Turnaround · #12 12-01-2011, 03:39 PM

Quote:

Originally Posted by georgestrings

Just a guess, but the harmonic *might* read a little more accurately than an open note - I'm guessing that because some tuners that don't track well with low notes(B, C, etc...) will usually track better with the 12th fret harmonic...

Not only that, but I suppose it's possible that if the intonation is actually off, the open note and 12th fret harmonic actually may not "agree" with one another...

- georgestrings

I agree with the bit about tuners tracking the harmonic better. But an open note and it's octave harmonic have to agree with each other. The harmonic occurs at the primary node of the vibrating string which is half the length of the string. Half the length equals twice the frequency equals one octave. It can't vibrate at a different frequency.

walterw · #13 12-01-2011, 07:00 PM

right, that harmonic will be in tune with the open note no matter how you adjust the saddles; it's therefore a waste of time to compare the open with the harmonic. you want to compare one or the other with the fretted notes.

the exception is a bad string; that's what makes it bad, the upper harmonics sounding out-of-tune with the fundamental.

Foamy · #14 12-01-2011, 07:10 PM

Are you sure this isn't the Double Bass forum? Just joking - I love it though.

Slowgypsy · #15 12-01-2011, 09:06 PM

The good folks over at Peterson Strobe Tuners have an article about setting intonation. They bluntly say that using their Strobe Tuner (of course) as a measuring guide, compare the open note with EITHER the fretted note or flageolet (harmonic). Since tuning is their business, I'll take their word for it.

walterw · #16 12-01-2011, 09:33 PM

read it again; i doubt it says to compare the open string with its flageolet, because that doesn't tell you anything.

Slowgypsy · #17 12-01-2011, 10:18 PM

Quote:

Originally Posted by walterw

read it again; i doubt it says to compare the open string with its flageolet, because that doesn't tell you anything.

You're right. I just got back from a 3 hour gig and my mind is in it's mush state. I need my glass of wine

MglMatador · #18 12-02-2011, 10:01 AM

Here's how I think about it.

On a fretless bass, you can (for all intents and purposes) play any note on any string perfectly in tune just by using your ear as a tuner (which you should!) regardless of the saddle positions of each string. Now it is convenient for common relationships between strings (like 5ths and 3rds) for these notes to be in the expected places string-to-string, but I digress.

Take a random string with a random tuning (and a random saddle position/string length) on an unlined fretless: start with a finger at the nut, and start sliding it upward while playing and you'll soon arrive at a perfectly in tune note. Take a sticker dot and place it right where the note lies, then continue to the next note. Once you arrive at the end of the fretboard you should see the familiar fret line logarithmic pattern based on the specific length of THAT string.

The idea of intonation is to adjust the length of each string so that these note locations lie (as close as possible) to the actual locations of the frets on a fretted fingerboard. This is in reality impossible to achieve on all strings at once (mainly due to tension, string width, and winding differences between strings) and also due to the fact that frets are (commonly) straight lines. By picking the 12th fret, we try to average the errors across the entire string length so that any random note is not too 'off'.

Turnaround · #19 12-02-2011, 11:52 AM

For those with OCD, you might want to consider the 7-12-17 intonation method. Start be getting setting the intonation at the 12th fret. Then check it at the 7th and the 17th. If it's not spot-on for all three locations (often it isn't), find the best compromise where they all all off by about the same amount.

To do this accurately, you will need to ensure that you fret at each location with exactly the same force. Squeezing the string harder at any location will drive the pitch a whisker sharp. Also be sure that you are not bending the string, but are following a truly vertical path from the position of the string at rest to the fingerboard (vertical meaning following the radius of the curve of the board). To do these things accurately you will need a jig to ensure the correct depression angle and force. And since the results may be affected by ambient temperature, it's best to carry out the intonation in an accurately controlled temperature environment where the air is dead still and there are no other vibrations (sounds) that can affect the behaviour of the string.

(Cough...)