Flat at the 12th fret?????????

[billiam5billion]

Swapped bridges on my Squier P-bass today. Got the action right, then got EADG open and ADGB at the fifth fret, but now every string is slightly flat at the 12th fret. Tried to adjust to get the 12 fret lined up and working, but then it was sharp at the 5th fret?!?!?!

I'm pretty new to doing my own setups, but I had no problem with my fender J or my friend's Fender P when he replaced his bridge, what am I doing wrong here? What makes the strings flat at the 12?

Please, PLEASE don't tell me to bring it to a tech, I'd like to exhaust all of my knowledge and yours before I gotta pay somebody for a setup.

[BigOldHarry]

you need to intonate your bridge. If you don't know how to do that, then guess what: TECH TIME!

[billiam5billion]

Well, I know that if the fretted 12th is flat, I should move the saddle closer to the neck, and visa versa, right? I tried that, but then as soon as the 12 is a perfect E, the open string is E, but the fifth fret is sharp. Is it just that some (cheap) basses just don't intonate well?

[hdracer]

If it is right on the 12th and open, your 5th fret is off. hoe are the rest?

[billiam5billion]

Originally Posted by hdracer

If it is right on the 12th and open, your 5th fret is off. hoe are the rest?

I can get a G and a C at the third pretty well, the red light on my tuner flickers sharp, but nowhere near as bad as the 5th.

[DuckVanMojo]

Just making sure... you're tuning up after you adjust the saddles, correct?

EDIT: I'll be more specific. So you've tuned all four strings, and you find that you're flat at the 12th fret. So you adjust the saddles to compensate (don't ask me which way to move them, I ALWAYS forget). Do you then tune all your strings again BEFORE checking the 5th fret?

[billiam5billion]

Originally Posted by DuckVanMojo

Just making sure... you're tuning up after you adjust the saddles, correct?

EDIT: I'll be more specific. So you've tuned all four strings, and you find that you're flat at the 12th fret. So you adjust the saddles to compensate (don't ask me which way to move them, I ALWAYS forget). Do you then tune all your strings again BEFORE checking the 5th fret?

I tune after each individual adjustment, yes.

[jmercer91]

it's never gonna be perfect on all frets, but if you've got the open and the 12th in then you should be good. if it really bothers you, then try to get a setup with less neck relief

[Labi]

Originally Posted by jmercer91

it's never gonna be perfect on all frets, but if you've got the open and the 12th in then you should be good. if it really bothers you, then try to get a setup with less neck relief

But he says it's sharp on the fifth. How is that good?!?!

@OP
Was it OK before you changed the bridge? What bridge did you put? Any before and after pics?

[David1234]

If you're using the same strings, they might have a kink where the old bridge saddle bent them, and the new bridge will most likely not have the exact same length from the string's ball end to the saddle. If so, this kink might be messing with the intonation and the problem won't be there with your next set of strings.

[dvh]

Or put the old bridge back on. Was it a necessary mod?

[JPSBassist]

Did you change strings?
I'd recommend putting a new set of strings on it.

Strings develop tension points and if the new bridge sits a hair differently than the old, or the saddles are shaped differently, you might be looking at something as simple as a string that's stretched over time and isn't sitting with the new saddles well.

Also, make sure your cores NOT are twisted. When you take the string off, does it spin? Hex core strings help prevent this... but I teched a bass I picked up that had been demo'ed by a pretty big name bassist (with a tech) and it sounded crappy, so I decided to restring it and bam! The cores on the B, E, A strings were twisted.

You'll never get proper tune out of a string with a twisted core, nor will it ever intonate correctly.

Also be sure to stretch new string after putting them on.

I say look less at the bridge and more at the strings. Hope this helps.

[billiam5billion]

Originally Posted by Labi

But he says it's sharp on the fifth. How is that good?!?!

@OP
Was it OK before you changed the bridge? What bridge did you put? Any before and after pics?

I don't know actually, the old bridge was pretty messed up, it had been dropped or something so the heads of a few of the saddle screws were flattened out, and the plate at the string holes was bent over. I had a spare bridge from another Squier I had fixed up so I just replaced the whole thing. The two Squiers were both from the late 2000's, so I don't see the bridges being different. I'm at work at the moment, maybe pics later.

[JPSBassist]

Originally Posted by David1234

If you're using the same strings, they might have a kink where the old bridge saddle bent them, and the new bridge will most likely not have the exact same length from the string's ball end to the saddle. If so, this kink might be messing with the intonation and the problem won't be there with your next set of strings.

Ha! We were typing this at the same time. I agree. I'd put my money on the strings being the culprit here.

[Floyd Eye]

http://www.tunemybass.com/bass_setup...ntonation.html

[billiam5billion]

New strings, there were only three on it when it got to me.

Okay, well...new OLD strings. I had a spare set. I'll swap strings tomorrow and see what happens.

[billiam5billion]

Originally Posted by Floyd Eye

http://www.tunemybass.com/bass_setup...ntonation.html

You know what? The last line of this I think is my answer-"Fretted instruments can't be perfectly intonated."

[billiam5billion]

Thanks for everyone's input!

[JPSBassist]

Originally Posted by billiam5billion

New strings, there were only three on it when it got to me.

Okay, well...new OLD strings. I had a spare set. I'll swap strings tomorrow and see what happens.

Cool. I'd be curious to see if a fresh set fixes it. Any time I've had weird intonation issues, a change of strings fixes things. Strings get old and need replacing sometimes.

Because I was a guitarist for many years, changing strings isn't a big deal to me... you change strings on guitars all the time. They go dead quickly.

Anyway... I look forward to the results.

[bggeezer]

Truss Rod?