Intonation above the 12th fret

[marob]

Well, I've searched for an hour and a half now, and I can't find a good solution to my problem.

When my bass in tune at the 12th fret, the 24th fret is sharp, about 15-20 cents on each string. If the 24th fret is in tune, the 12th fret is flat.

Any advice?

I have some faint ideas of why this is happening, but I'll wait and hear from you.

[Poop-Loops]

It's how stringed instruments like guitar and bass are made. You won't get it perfect. I think it's called Equal Temperment or something like that. The Buzz Feiten tuning system takes care of that, but some people don't like it. I think it causes cancer or something (because I can't find anything wrong with it, myself).

[69nites]

Intonate at the 12th and 19th fret

if you can't get them both perfect find the happy medium between the 2

[vicenzajay]

Adjust the intonation for each string at the bridge. Get a strobe tuner (or a good optical one) and tune each string to pitch. The "half-string" harmonic will be (should be) close to the 12th fret, and it should also be in tune as the open string has been tuned.

Now fret the string at the 12th fret - compare (on the tuner) the pitch of the fretted note with the harmonic. If it's sharp - adjust the bridge to lengthen the open string (i.e. move the bridge saddle toward the "butt" of the bass). If it's flat, you need to adjust the saddle toward the neck. Retune the open string and check again. Do this until you get the pitch of the 12th fret harmonic and the 12th fret in tune (intonated) with each other.

Do a search for "intonation" here...there are a lot of folks who are smarter at describing this than I am. Once you've done it, you'll feel more confident and do it more quickly the next time. You should intonate your strings every time you change strings or make a truss rod adjustment.

Jay

[lonote]

Originally Posted by 69nites

Intonate at the 12th and 19th fret

if you can't get them both perfect find the happy medium between the 2

I've been doing it this way for years and it works very well for me. I learned this method from reading an article written by Rick Turner.

[SteveC]

Originally Posted by vicenzajay

Adjust the intonation for each string at the bridge. Get a strobe tuner (or a good optical one) and tune each string to pitch. The "half-string" harmonic will be (should be) close to the 12th fret, and it should also be in tune as the open string has been tuned.

Now fret the string at the 12th fret - compare (on the tuner) the pitch of the fretted note with the harmonic. If it's sharp - adjust the bridge to lengthen the open string (i.e. move the bridge saddle toward the "butt" of the bass). If it's flat, you need to adjust the saddle toward the neck. Retune the open string and check again. Do this until you get the pitch of the 12th fret harmonic and the 12th fret in tune (intonated) with each other.

Do a search for "intonation" here...there are a lot of folks who are smarter at describing this than I am. Once you've done it, you'll feel more confident and do it more quickly the next time. You should intonate your strings every time you change strings or make a truss rod adjustment.

Jay

This is what I do as well. I remember it as sharp-in and flat-out for moving the bridge saddles.

[Bass]

I remember it as "the three F's": Fret - Flat - Forward.

If the fretted note is flat, move the saddle forward.

[EADG mx]

Try adjusting for the 19th fret instead of the 12th. It might be as simple as that.


Don't expect to get all of your frets perfectly in tune. Unless you have the BF system, or fanned frets, it's most likely never going to happen.

[pkr2]

If you cannot get it any closer than 10 to 15 cents, you are doing something real wrong. That's a LOT of intonation error.

There is no way for us to know if you are just learning to do setups or are if you fairly experienced.

What results are you getting as you adjust the intonation screws? Have you ran out of adjustment and it wont reach intonation? Has it ever intonated properly? Are you using a non standard tuning? Have you changed string guages drastically. Are you CERTAIN that you've got the proper procedure in the right order? The steps have to be done in a precise order or you end up chasing your own tail.

Give us something to go on.