Double Bass String Depth in Nut

[Meddle771]

How far should the string be into the nut? How high is it suppose to be off the FB on the low F/Bb/Eb/Ab?

Hopefully I'll be able to make a trip out to my luthier to get it looked at on Saturday.

 

[Jake deVilliers]

The string should be 'cupped' in the nut grooves, maybe a third of the string's diameter, just deep enough to keep them from popping out.

The string height question is a little more complicated. In a perfect world there might be 10-12 thousands of an inch clearance at the nut and 5, 6, 7 & 8mm at the end of the fingerboard BUT - the board will have to be in good shape with the right amount of camber in the right part of the fingerboard and no humps or dips.

As far as I'm concerned, a true setup starts with the fingerboard and proceeds from there.

Good Luck!

 

[bejoyous]

Having the string about the thickness of a business card or a dollar bill above the fingerboard right at the nut is a good height. So that is less than a mm.

That way, the string is easy to hold down in 1/2 and 1st position and it shouldn't buzz on open strings. It'll make notes higher up on the board easier to hold down and play in tune, as well.

If the space there is too high, when you finger a note, the string bends in from both the bridge and the nut, much like the bending of a bow & arrow string. If the height is low, when you hold down a note, the string between the nut and your finger is pretty much flat against the board.

The luthier will use some round needle files to lower the grooves to the right height. This is not hard to do yourself, just be sure the front edge of the nut, where it meets the fingerboard, is the highest part of the groove. Use lots of pencil in the groove to lubricate it before you put the string back on. Put some pencil in the groove of the bridge and give the string a deep cleaning with methyl hydrate or rubbing alcohol (see #8 of this thread) while you are at it.

Remember you can only remove wood and not put more back on, so go slowly when you are nearing the end. However, if you go too low, there are several ways to increase the height slightly, but I won't go into that right now.

If you are doing this yourself, do it one string at a time so the pressure is always on the belly of the instrument and the soundpost won't fall down.

 

[robobass]

The string should be 'cupped' in the nut grooves, maybe a third of the string's diameter, just deep enough to keep them from popping out.

The string height question is a little more complicated. In a perfect world there might be 10-12 thousands of an inch clearance at the nut and 5, 6, 7 & 8mm at the end of the fingerboard BUT - the board will have to be in good shape with the right amount of camber in the right part of the fingerboard and no humps or dips.

As far as I'm concerned, a true setup starts with the fingerboard and proceeds from there.

Good Luck!

+1. As far as notch depth, a third of the diameter sounds right - maybe up to a half. You see nuts and bridges with much deeper slots, and the basses never seem to sound very good. Probably not a result of the notches directly, but they serve as an indicator of overall luthier knowledge, skill, and concientiousness. As far as fingerboard clearance at the nut, I go for about .004", the thickness of a fresh US federal reserve note i.e. dollar bill (A business card is usually much thicker). As Jake said, though, such low clearance requires a very well dressed FB.

 

[IdealWay]

I hadn't considered this until reading this thread, and after checking my bass I noticed that the A, D, and G strings are fully submerged in the nut grooves. The E string sits about 1/2 way out. Is there an easy way I can remove some of the wood so they're not sunken so far in, without potentially doing any damage? What kind of effect would it have on my tone? I also noticed that the D and G strings are fully covered at the bridge slots too. Yikes! Any help would be appreciated.

 

[IdealWay]

Here are a couple pics for clarity:

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[Jake deVilliers]

I hadn't considered this until reading this thread, and after checking my bass I noticed that the A, D, and G strings are fully submerged in the nut grooves. The E string sits about 1/2 way out. Is there an easy way I can remove some of the wood so they're not sunken so far in, without potentially doing any damage? What kind of effect would it have on my tone? I also noticed that the D and G strings are fully covered at the bridge slots too. Yikes! Any help would be appreciated.

For in situ work like that I use a little 6" Nicholson Mill Bastard file with the edges ground smooth. It cuts cleanly enough that I can use it cross grain or on the diagonal to maintain the smooth radius of the top of the nut.
Of course a better finish can be obtained by removing the nut from the bass but then you need to worry about the soundpost...

I would just loosen off the A and D strings and file until the strings are held nicely, then replace the A and move the G string out of the way and continue the shape right across. Finish with 320 grit paper if you like.
Then do the same with the bridge.

Report back on the difference in sound when you're done!

 

[IdealWay]

Thanks for the tips Jake!

I went out and got the 6" Nicholson and some sandpaper and did the job while changing strings. Just took my time and checked the depth periodically until it was at the right level, pretty easy really. I wasn't able to do a legit a/b comparison since I went from Helicore's to Spiro Mittels at the same time, but I will say that YOWZA this is a whole new bass! The tone is much more rich and vibrant, and the biggest difference I've noticed is in the sustain. It makes good sense that by freeing up the strings they can vibrate longer and more freely. So, for all of you noobs out there (like me) who haven't checked your nut and bridge, I highly recommend doing so and following Jake's process for fixing them if need be.

 

[Jake deVilliers]

Thanks for the tips Jake!

I went out and got the 6" Nicholson and some sandpaper and did the job while changing strings. Just took my time and checked the depth periodically until it was at the right level, pretty easy really. I wasn't able to do a legit a/b comparison since I went from Helicore's to Spiro Mittels at the same time, but I will say that YOWZA this is a whole new bass! The tone is much more rich and vibrant, and the biggest difference I've noticed is in the sustain. It makes good sense that by freeing up the strings they can vibrate longer and more freely. So, for all of you noobs out there (like me) who haven't checked your nut and bridge, I highly recommend doing so and following Jake's process for fixing them if need be.

Congratulations!

You heard the same things I always hear - a big increase in sustain and ring brought about by a greater freedom of movement for the strings.

 

[Waltjie]

When I got my bass, which is almost a year ago, the nut was way to high, and so, like many other people do I just went out and got myself some small files and made the string grooves deeper to lower the action.
The result was almost identical to the pictures posted here. After having read this thread last week, I decided to take the risk and try to fix it myself.
Well I am happy to say that I succeeded and WOW! Yes, it makes a huge difference in sustain (especially) and also in tone somehow.
People really shouldn't underestimate the importance of a nut being correctly setup.

 

[Eric Hochberg]

I wasn't able to do a legit a/b comparison since I went from Helicore's to Spiro Mittels at the same time, but I will say that YOWZA this is a whole new bass!

Going from Helis to Spiros will do this.