Intonation on all frets - how good should it be?

[baboom]

I tried an alleged Highway-1 P-bass (second hand) this morning and on a paranoid whim, when it took the guy a while to "remember" what shop he bought it from a year ago, I took out my tuner (Korg pitchblack) and checked the intonation at each of the frets.

On the bottom string (E), the open and 12th fret were in good agreement, but the 1st and 2nd frets were sharp (making some assumptions about the linearity of the lights on the tuner display, it seemed like they were up to 1/8th of a tone out - which seems too much).

On the top string (G), the open and 12th fret were again in good agreement, but the highest few frets (17/18) were similarly sharp.

This doesn't seem right to me - surely the fretboard on a half decent bass should be constructed so that all the frets play at the correct pitch when it is properly setup. But when some notes are sharp whilst others are flat (didn't note which ones those were, but there were some), on the same string as appeared to be the case on this bass, it seemed to me there is no straightforward way to recover the situation so I walked away.

But then I got to wondering just how good the intonation is generally expected to be. I also appreciate a stage tuner is not the most precise beast on the planet for intonation work .... but I tried the same game on a MIM Precision in a shop and got pretty good intonation on all frets, and a cheapy bass and that was fine too (at least up to the 15th fret).

I'm now starting to doubt I could have found a genuine fender bass with a problem like that or that I made some mistake in my approach but it was repeatable at the time. To be honest, I couldn't put my finger on any obvious sign of it not being what it said it was, either.

Has anyone come across this problem before?

p.s. the bass has not been advertised on bass chat - was on a local website.

[Moos3h]

Nut height can affect intonation, I believe.

So can old, knackered or cheap strings.

Oh, and pickup height too!

[mrcrow]

[quote name='Moos3h' post='674974' date='Dec 5 2009, 02:56 PM']Nut height can affect intonation, I believe.

So can old, knackered or cheap strings.

Oh, and pickup height too![/quote]

+1

just been doing that now with fitting a new bridge
i stick to the tunings on harmonics frets 5/7 and the intonation on fret 12
i was checking out of interest the harmonics on fret 3 to 24th fretted note...quite good on G D and E but A string was out on the top A
i seem to recall also apart from what Moos3h says is that frets ideally should be fanned in a pattern which ends in the angle of the saddles after setting intonation
my A saddle is further back than the E so i reckon my A string is a bit stiff around its end where it meets the bridge and so may account for my findings
for me as i dont play above the 12th fret really setting intonation on that area is sufficient for my needs

Edited December 5, 2009 by mrcrow

[baboom]

Thanks for the replies guys - sounds like it might not be as bad as I had thought. I've found something else, but I'll try and give the guy a call/email and pass those points along anyway.

[noelk27]

[quote name='baboom' post='674972' date='Dec 5 2009, 02:48 PM'][S]urely the fretboard on a half decent bass should be constructed so that all the frets play at the correct pitch when it is properly setup. But when some notes are sharp whilst others are flat ...[/quote]

Ah, the joys of equal temperament. The plus or minus you observed is simply one of the characteristics of fretted touchboards. The only true way for you to check the intonation is to use harmonics, as harmonics are intonation stable.

[BigRedX]

Lets get this straight.

Did you check that the harmonic at the 12th fret and the fretted note were equal? Unless this is the case the other measurements you took are meaningless.

If so were you pressing down exactly at 90° to the fingerboard when you fretted the note. Any deviation to this will stretch the string more causing it to go sharp.

Tuning the strings relative to each other using harmonics is not the right way to do it as on an standard equally tempered fretboard only the 12th fret and it's harmonic will be in tune and then only if the bridge has been adjusted properly. If you use the harmonics to tune the strings to each other because they don't match the fretted notes exactly the fretted notes will not be exactly in tune with the same note on a open string.

Could you notice that the fretted notes were out of tune with out the aid of your tuner?

If so and there was nothing wrong with either the position or the relative profile of the frets, then you are going to need to consider playing basses with[url="http://www.truetemperament.com/site/index.php?go=1&sgo=4"]true-tempered necks[/url]

[mrcrow]

[quote name='baboom' post='674972' date='Dec 5 2009, 02:48 PM']On the bottom string (E), the open and 12th fret were in good agreement, but the 1st and 2nd frets were sharp[/quote]

thats the F and F#
does your tuner actually measure these notes

[BigRedX]

Just had a look at the tuner you used.

Am I right in saying that it doesn't actually give you a display of the note in cents? Just tells you which note you're closest to and then some LED segments to tell you how sharp or flat you are to that note, but no actual scale?

In which case you have no idea what each segment actually represents and whether the scale is linear or logarithmic.

Therefore unless you could actually hear that the notes in question were out, I'd say it's a lot of fuss over nothing.

[mrcrow]

[quote name='BigRedX' post='676749' date='Dec 7 2009, 02:32 PM']Just had a look at the tuner you used.

Am I right in saying that it doesn't actually give you a display of the note in cents? Just tells you which note you're closest to and then some LED segments to tell you how sharp or flat you are to that note, but no actual scale?

In which case you have no idea what each segment actually represents and whether the scale is linear or logarithmic.

Therefore unless you could actually hear that the notes in question were out, [b]I'd say it's a lot of fuss over nothing.[/b][/quote]

listen to the playing and accept unless you can virtually see the frets are out of line...its ok
tuners are for tuning up