Low cut nut or high 1st fret?

smeet

smeet

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Nov 27, 2006
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#1
I’ve got a Lull 5-string bass that plays well, but the open low B string rattles/buzzes. So either the nut slot for the B is cut too low, or the first fret is too high under tha B string. How do I tell which it is, and is there a way to fix it myself without specialized tools or lots of experience?

Thanks!
 
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#2
smeet said:
I’ve got a Lull 5-string bass that plays well, but the open low B string rattles/buzzes. So either the nut slot for the B is cut too low, or the first fret is too high under tha B string. How do I tell which it is, and is there a way to fix it myself without specialized tools or lots of experience?

Thanks!
Click to expand...

Simple answer: depress the string directly on top of the 3rd fret. You should be able to slide a .003-.005" feeler gauge between the string & 1st fret. 2nd option: place a small aluminum foils pellet in the B string slot. Does the buzz disappear?

I'll assume the balance of the set-up is within spec...relief, string height, witness points, break angles / string wraps.

Riis
 
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#3
It seems to me that would only verify that the geometry between the nut and first fret are wrong, which we already know. The nut could be cut too low, or the first fret is too high. Would it make sense to see if the first fret is too high? That is.....see if the first fret is level compared to the others?
 
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#4
Old Fart said:
It seems to me that would only verify that the geometry between the nut and first fret are wrong, which we already know. The nut could be cut too low, or the first fret is too high. Would it make sense to see if the first fret is too high? That is.....see if the first fret is level compared to the others?
Click to expand...
How do I do that? Can I just lay a straight edge across the frets? Do I need to crank the truss rod to flatten out the neck first?
 
#6
smeet said:
How do I do that? Can I just lay a straight edge across the frets? Do I need to crank the truss rod to flatten out the neck first?
Click to expand...
Fret rocker or a broken machinist scale. Something that's about 3" long. That way, you don't pick up the neck relief, just the adjacent frets.
Put a simple piece of thick paper in the low nut slot. Keep adding until the buzz changes. Then there's this.
 
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#7
smeet said:
How do I do that? Can I just lay a straight edge across the frets? Do I need to crank the truss rod to flatten out the neck first?
Click to expand...
You need something that has a straight edge and covers just the first three frets. Lay it on 2nd and 3d frets and slide it towards the first fret. If you feel a bump when it reaches the first fret, then it’s too high. (You would get the same result if the 2nd fret is too low, or if the 3rd fret is too high, but that would give buzz at the 2nd fret. Still, to be absolutely sure, you can use the straight edge to make sure that’s not the case by placing it on the 2nd, 3rd, and 4th frets and see if it rocks.)

Be careful not to scratch the frets when you do this. A soft material like plastic is best, be very careful with steel (I scratched my frets once when I used a fret rocker for this and had to polish them afterwards).

I guess straightening the neck first would be best, but you’ll probably also notice with a neck with a normal amount of relief.

Edit: on second thought, since you’re dealing with the first fret, I’d say straightening the neck beforehand is necessary. The curvature of the neck in this area is probably strong enough, and the distance between the frets long enough, to make a significant difference. Feeling that ‘bump’ there is probably normal if the neck isn’t perfectly straight.
 
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#8
Fret the string at the second fret and see if there is any space between the first fret and the string, any at all. Determining if it’s a high first fret or a low but can be accomplished with a short straightedge, by seeing if the straightedge rocks when placed across the nut, first fret, and second fret.

If it’s a low nut, an easy temporary fix is to use a bit of superglue in the nut slot to raise it up just a hair. You have to be careful and mask off everything around it with masking table, and only use a tiny bit in the slot to raise it very slightly. There are YouTube videos out there showing how to do this, make sure you watch them before trying it.
 
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#9
It almost definitely won't be the fret, it will be the nut.

Tear a small piece of tissue and add it under the string in the slot. It will temporarily fix the issue. You might need to fold it to get the required thickness. It's not a permanent solution but it works in a pinch.

Also, low strings (B and E) have a bad habit of rattling after a string change. If you have a spare B around of a different gauge/manufacturer try it and see if it stops the issue. If the nut slot is cut particularly low, a string change (lower tension) can cause the neck to straighten just enough to get the signature rattle.
 
#10
MotorCityMinion said:
Fret rocker or a broken machinist scale. Something that's about 3" long. That way, you don't pick up the neck relief, just the adjacent frets.
Put a simple piece of thick paper in the low nut slot. Keep adding until the buzz changes. Then there's this.
Click to expand...

I got similar results with Super Glue Gel without using any dust. A bit easier to perform, less messy and seems to work fine so far. I did it one year ago and it’s still okay but I don’t know how it will hold on the long term. I feel confident nonetheless.
 
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#11
If you have a .020" feeler gage (or stack a couple to make .020), I 'd start with checking for that clearance between each string and the first fret, tuned to pitch and no notes fretted, do it with each string 'open'.

This would tell me where I'm at and where to go next. .020" may not be the factory spec, but generally a pretty good number.
 
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#12
Kind of the same way you check for relief on the truss rod. Use the string as your straight edge.
Fret down on like the third or fourth fret. Then look and see if there is ever the slightest gap between the string and the first couple of frets.
 
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#13
BismarckHerring said:
.... since you’re dealing with the first fret, I’d say straightening the neck beforehand is necessary.....
Click to expand...

I'd say that too. The proper diagnostic method would likely be to remove the strings and use the truss rod to get the neck as straight as possible. It could take some time for the neck to relax into its best 'straightness.' Then use a long straight-edge. Put the straight edge along all the frets, right in the CENTER of the neck where the dots are. Use feeler gauges to measure between the bottom of the straight edge and the frets. The straight edge will be laying against at least two frets. One of them will likely be the first fret. Measure at the second fret, and the third, and the fourth. Bring those numbers back here.

But there may be a shortcut. A "fret rocker" is a very inexpensive and useful tool for many things. Like checking fret heights but also measuring string height, pickup height, etc. Honestly, one thing I might do in your shoes with a fret rocker is to lay it across frets 2, 3 and 4, then measure from the fingerboard to the bottom of the fret rocker at the 2nd fret. Between the 1st and 2nd fret, but right against or very near to the 2nd fret. Then I'd do the same thing at the first fret with the fret rocker across frets 1, 2 and 3. You'd be basically measuring the heights of the first and second frets. If the first fret is more than about a thousanth higher than the second fret, then the first fret is too high.....but that's a guess. A luthier could likely tell you what is the tolerance here. The acceptable difference in height between those two frets. I'm guessing a thousanth, but perhaps 2 or 3 are allowable. I am not a luthier.
 
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#15
GroovinOnFunk said:
Kind of the same way you check for relief on the truss rod. Use the string as your straight edge.
Fret down on like the third or fourth fret. Then look and see if there is ever the slightest gap between the string and the first couple of frets.
Click to expand...
I just did that, no gap at all at first couple of frets when fretting at the 3rd or 4th fret.

What does that mean? When I fret the E string (no rattle) at 3rd or 4th fret, there a tiny gap at the first fret (I can't see it but when I tap the string I hear it).
 
#18
smeet said:
When I fret the E string (no rattle) at 3rd or 4th fret, there a tiny gap at the first fret (I can't see it but when I tap the string I hear it).
Click to expand...

What does this mean? When you play the open B string there is fret buzz. Is there fret buzz when you play the C, a half-step up.? Or a C# or D? If the buzz is only on the open E string, then I'm still not 100% certain the nut slot is cut too low but it becomes more likely.

GroovinOnFunk said:
Sounds like a low nut slot then.
Click to expand...

Very possibly. I'd like to see the experiment I suggested, which is basically a method of measuring the heights of the individual frets above the fingerboard. But if you don't have feeler gauges then you're guessing and I'd guess you're not sure you want to pay a luthier. In that case, it might be interesting to put one or two tiny pieces of household aluminum foil between the B string and the bottom of the nut slot. That's likely to fix the buzz. You still won't know whether it is the nut slot or the fret that needs modification, but you'd have a B string that does not buzz and you will likely forget about all this and just play your bass.
 
#20
Old Fart said:
What does this mean? When you play the open B string there is fret buzz. Is there fret buzz when you play the C, a half-step up.? Or a C# or D? If the buzz is only on the open E string, then I'm still not 100% certain the nut slot is cut too low but it becomes more likely.



Very possibly. I'd like to see the experiment I suggested, which is basically a method of measuring the heights of the individual frets above the fingerboard. But if you don't have feeler gauges then you're guessing and I'd guess you're not sure you want to pay a luthier. In that case, it might be interesting to put one or two tiny pieces of household aluminum foil between the B string and the bottom of the nut slot. That's likely to fix the buzz. You still won't know whether it is the nut slot or the fret that needs modification, but you'd have a B string that does not buzz and you will likely forget about all this and just play your bass.
Click to expand...
The only note that rattles on the bass is the open B string.
For now I’ll probably put foil under the B. When I have time I’ll go to my luthier. And yeah I don’t have feeler gauges. I might get a set of setup tools. What’s the best set to get? I was looking on stewMac and was getting confused about what I might need and what I might never use.
 
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