Nut height: *very* important for low action?

[dbcandle]

I've read posts (on another board, as I recall) that "action begins with the nut". I've not seen it discussed so much here, though, and I've frequented here quite a bit (both "lurking" and recently posting).

How important is the string-height at the nut in getting "low action" on a mass-produced bass (MIM Jazz, in my case). I don't seem to recall in mentioned much in the "sticky" threads, and Fender's guide does not seem to mention it all all.

I've got some info/specs in Erlewine's book, but I was wondering if it is significant, or if I'm "splitting hairs". My Ibanez has a little lower action, and the height at the nut is a bit lower too. May just be a coincidence...

[glwanabe]

It is very important!!

There is no reason to not spend a couple of extra bucks and put a proper nut on your bass. Then spend the time to really dial it in to a proper height. After changing my nut to a graph tech unit, and then lowering it so I have .001 clearance at the first fret while depressed at the third. I can get away with about a 5/64" action with a relief of .012". This is plenty low, and I can get some fret sizzle by digging in a little harder If I want to.

I've also recently turned my attention, to the vintage style bridge on my basses. I've made some discoverys after tearing apart my BAII bridges and really looking at what made them sound different as compared to vintage style bridges. After applying a couple of tweaks to the vintage style bridge, it now sounds and offers better performance than the BAII bridge ever did! This has to do with "Stored" energy in the bridge and energy transfer, by the springs used on the barrells.

All aspects of the instrument work together, to create the final result.

[202dy]

Originally Posted by Joshua

Let's see if I can give this the priority it deserves:

Nut height is VERY important in regards to setting action.

Sorry, old pal. Let me see if I can disagree.

Nope. Nunca. Nyet. Non. Nah. No.



Nut height is important only in setting string height at the first (few) frets. Beyond the third fret it is pretty meaningless. In some cases it can be important in preventing back buzz.

Before arguing the point, consider the geometric relationship of nut, bridge, fingerboard, and string. As fond as we are of viewing this picture as a triangle, it is not. It is a trapezoid. And a very acute on at that. What that means is that the string has an "advantage" in that it is taking off from a raised point. But since the angle is so acute, even a drastic rise (or lowering) in height has a negligible effect on string height at F12 or F20-24.

So as far as setting string height and action overall, it is pretty meaningless. But it is very important in determining the feel at the first fret or three.

[glwanabe]

Originally Posted by 202dy

Sorry, old pal. Let me see if I can disagree.

Nope. Nunca. Nyet. Non. Nah. No.



Nut height is important only in setting string height at the first (few) frets. Beyond the third fret it is pretty meaningless. In some cases it can be important in preventing back buzz.

Before arguing the point, consider the geometric relationship of nut, bridge, fingerboard, and string. As fond as we are of viewing this picture as a triangle, it is not. It is a trapezoid. And a very acute on at that. What that means is that the string has an "advantage" in that it is taking off from a raised point. But since the angle is so acute, even a drastic rise (or lowering) in height has a negligible effect on string height at F12 or F20-24.

So as far as setting string height and action overall, it is pretty meaningless. But it is very important in determining the feel at the first fret or three.

If your nut is to high you will be out of tune when fretting in those first few frets.

The proper nut height has effects beyond just feel, but that is definately the most noticeable when it is to high.

[202dy]

Originally Posted by glwanabe

If your nut is to high you will be out of tune when fretting in those first few frets.

The proper nut height has effects beyond just feel, but that is definately the most noticeable when it is to high.

That is correct. But the question the OP asked deals with setting action. A simple review of the geometry dictates the proper response.

Intonation is another subject.

[dbcandle]

My primary concern is "action" (string-height) at the 17th fret.

[glwanabe]

Originally Posted by 202dy

That is correct. But the question the OP asked deals with setting action. A simple review of the geometry dictates the proper response.

Intonation is another subject.

Well, if your nut is to high then your action is high in that area of the bass, but that is splitting hairs. The intonation aspect is another branch to look at as well.

I agree that you can set your action at the 17th fret, to be low, and yet have your nut cut to high for optimum playability.

The basic answer is that, you need to have your nut cut to the proper height, to realize optimum playability over the whole range of the instrument. As I said earlier, all the parts interact to create the final product.

[Darkstrike]

Originally Posted by glwanabe

It is very important!!

There is no reason to not spend a couple of extra bucks and put a proper nut on your bass. Then spend the time to really dial it in to a proper height. After changing my nut to a graph tech unit, and then lowering it so I have .001 clearance at the first fret while depressed at the third. I can get away with about a 5/64" action with a relief of .012". This is plenty low, and I can get some fret sizzle by digging in a little harder If I want to.

I've also recently turned my attention, to the vintage style bridge on my basses. I've made some discoverys after tearing apart my BAII bridges and really looking at what made them sound different as compared to vintage style bridges. After applying a couple of tweaks to the vintage style bridge, it now sounds and offers better performance than the BAII bridge ever did! This has to do with "Stored" energy in the bridge and energy transfer, by the springs used on the barrells.

All aspects of the instrument work together, to create the final result.

I'd really love to know more about these tweaks to the vintage bridge.

[glwanabe]

Originally Posted by Darkstrike

I'd really love to know more about these tweaks to the vintage bridge.

I had an AHA!! moment several weeks ago. I'm a nosey little snot and I like to know why things work. As well as tearing things apart to see how they are made.

I've worked in the aviation field for almost 18 years now. I spent my maintenance time working on Blackhawk helicopters.

Helicopters have lots of vibration problems because of all the moving parts. Blackhawks, have a few vibration dampening systems built into them. Well, if you can dampen vibrations out, you can focus vibrations in.

On to basses, and bridges:

When I took a look at the BAII I noticed a couple of things. First. The BAII string saddles are light, I didn't weight them, but they feel lighter than Fender saddles. Second, was the barrell screws, they felt like they were a bit more snug on the barrells. Third was the springs that were on the BAII adjustment screws, they were much tighter and stronger than Fender springs.

Thats when my years of helicopter flight testing and vibration dampening experience smacked me in the head.

The BAII bridge does not increase sustain simply because it weighs more. It increases sustain because it transfers more energy from the stored energy of the higher rate springs, and tighter tolerances of the moving parts.


I changed the barrell screws to a snugger fitting stainless screws, and started playing with varying spring rates.

EVERY single change in spring tension resulted in a change in sustain and resonance in the bass.

The original Fender springs were loose and were allowing energy to be dampened out, killing sustain, and not allowing for the bass to resonate.

I've gone through several sets of springs and I'm now using the BAII springs on vintage bridges. This is on both a MIM standard and a Geddy jazz. It should be noted that the Geddy jazz has a bridge location 5/16" further back than the standard. This effects the amount of stored energy in the springs on both basses. The standard has more stored energy in it's springs than the Geddy does.

Could it really be this simple, it appears to be so. The Blackhawk has a cabin vibration dampener, that is a spring loaded piece. You add weight or take it away to allow the dampener to resonate harmonically with the airframe, dampening vibrations.

The roter head has 4 pieces of weight, one for each blade that simply vibrate and allow energy to be dissapated.

Both my basses have as much sustain, the standard even more, than when they wore the BAII bridge. The resonance of the bass is improved because the Fender baseplate allows better energy transfer into the wood. The BAII baseplate actually isolates the bass body, hence the mid freq bump. While Fender bridges are considered to give the bass back it's bottom end.

Thats my story.

[202dy]

Originally Posted by Joshua

Chucklehead!



And you are correct in specificity. I was merely answering in the general sense that without the correct nut height, a completely successful low action setup would not be possible.

You are, as usual, correct in your answer as well.

Don't you just dig this stuff?





In regards to nut height affecting action at the 17th fret, refer to 202dy's post.

I guess I view nut height and set up as separate issues. They are not separate. They are related. But 95% of the set ups that come through the door we spend our time with the truss rod and the bridge and only occasionally adjust for nut height.

As far as excavation goes, some days it feels like digging ditches. Most of the time it's just makin' the doughnuts. But it still fascinates after almost four decades.

[202dy]

Originally Posted by glwanabe

I had an AHA!! moment several weeks ago. I'm a nosey little snot and I like to know why things work. As well as tearing things apart to see how they are made.

I've worked in the aviation field for almost 18 years now. I spent my maintenance time working on Blackhawk helicopters.

Helicopters have lots of vibration problems because of all the moving parts. Blackhawks, have a few vibration dampening systems built into them. Well, if you can dampen vibrations out, you can focus vibrations in.

On to basses, and bridges:

When I took a look at the BAII I noticed a couple of things. First. The BAII string saddles are light, I didn't weight them, but they feel lighter than Fender saddles. Second, was the barrell screws, they felt like they were a bit more snug on the barrells. Third was the springs that were on the BAII adjustment screws, they were much tighter and stronger than Fender springs.

Thats when my years of helicopter flight testing and vibration dampening experience smacked me in the head.

The BAII bridge does not increase sustain simply because it weighs more. It increases sustain because it transfers more energy from the stored energy of the higher rate springs, and tighter tolerances of the moving parts.


I changed the barrell screws to a snugger fitting stainless screws, and started playing with varying spring rates.

EVERY single change in spring tension resulted in a change in sustain and resonance in the bass.

The original Fender springs were loose and were allowing energy to be dampened out, killing sustain, and not allowing for the bass to resonate.

I've gone through several sets of springs and I'm now using the BAII springs on vintage bridges. This is on both a MIM standard and a Geddy jazz. It should be noted that the Geddy jazz has a bridge location 5/16" further back than the standard. This effects the amount of stored energy in the springs on both basses. The standard has more stored energy in it's springs than the Geddy does.

Could it really be this simple, it appears to be so. The Blackhawk has a cabin vibration dampener, that is a spring loaded piece. You add weight or take it away to allow the dampener to resonate harmonically with the airframe, dampening vibrations.

The roter head has 4 pieces of weight, one for each blade that simply vibrate and allow energy to be dissapated.

Both my basses have as much sustain, the standard even more, than when they wore the BAII bridge. The resonance of the bass is improved because the Fender baseplate allows better energy transfer into the wood. The BAII baseplate actually isolates the bass body, hence the mid freq bump. While Fender bridges are considered to give the bass back it's bottom end.

Thats my story.

This might be one of the most important ideas about replacement bridges posted on TB in the last year. It should be studied further.

[glwanabe]

Originally Posted by 202dy

This might be one of the most important ideas about replacement bridges posted on TB in the last year. It should be studied further.

I've been openly posting about this for about a week or so. I'd like for some others to duplicate my experiments. It has worked on both of my basses. I have a couple of friends that have vintage style bridges on there basses. I'm going to apply my theory's on their stuff. It should work.

[Darkstrike]

Originally Posted by glwanabe

I had an AHA!! moment several weeks ago. I'm a nosey little snot and I like to know why things work. As well as tearing things apart to see how they are made.

I've worked in the aviation field for almost 18 years now. I spent my maintenance time working on Blackhawk helicopters.

Helicopters have lots of vibration problems because of all the moving parts. Blackhawks, have a few vibration dampening systems built into them. Well, if you can dampen vibrations out, you can focus vibrations in.

On to basses, and bridges:

When I took a look at the BAII I noticed a couple of things. First. The BAII string saddles are light, I didn't weight them, but they feel lighter than Fender saddles. Second, was the barrell screws, they felt like they were a bit more snug on the barrells. Third was the springs that were on the BAII adjustment screws, they were much tighter and stronger than Fender springs.

Thats when my years of helicopter flight testing and vibration dampening experience smacked me in the head.

The BAII bridge does not increase sustain simply because it weighs more. It increases sustain because it transfers more energy from the stored energy of the higher rate springs, and tighter tolerances of the moving parts.


I changed the barrell screws to a snugger fitting stainless screws, and started playing with varying spring rates.

EVERY single change in spring tension resulted in a change in sustain and resonance in the bass.

The original Fender springs were loose and were allowing energy to be dampened out, killing sustain, and not allowing for the bass to resonate.

I've gone through several sets of springs and I'm now using the BAII springs on vintage bridges. This is on both a MIM standard and a Geddy jazz. It should be noted that the Geddy jazz has a bridge location 5/16" further back than the standard. This effects the amount of stored energy in the springs on both basses. The standard has more stored energy in it's springs than the Geddy does.

Could it really be this simple, it appears to be so. The Blackhawk has a cabin vibration dampener, that is a spring loaded piece. You add weight or take it away to allow the dampener to resonate harmonically with the airframe, dampening vibrations.

The roter head has 4 pieces of weight, one for each blade that simply vibrate and allow energy to be dissapated.

Both my basses have as much sustain, the standard even more, than when they wore the BAII bridge. The resonance of the bass is improved because the Fender baseplate allows better energy transfer into the wood. The BAII baseplate actually isolates the bass body, hence the mid freq bump. While Fender bridges are considered to give the bass back it's bottom end.

Thats my story.

Very intresting, and something I'm gonna try very soon!
Thank you.

[glwanabe]

I should also note regarding my bridges.

The Standard Jazz has vintage style threaded saddles.
The Geddy has the newer type single slotted saddles.

In theory, the threaded saddles should dissapate more energy, because of their design, but since the springs are storing more energy, I don't hear a sustain issue.

[ogrossman]

Originally Posted by glwanabe

EVERY single change in spring tension resulted in a change in sustain and resonance in the bass.

I wonder if more spring tension (actually compression) just loads up the screw threads more and takes out the lash... if that's true then a jamb nut at the saddle and a jamb nut where the screw passes through the bridge would be the ultimate solution.

(just a thought)

[glwanabe]

Originally Posted by ogrossman

I wonder if more spring tension [B](actually compression)[/B] just loads up the screw threads more and takes out the lash... if that's true then a jamb nut at the saddle and a jamb nut where the screw passes through the bridge would be the ultimate solution.

(just a thought)

I had thought about that as well.

Your correct with the term compression. I was using the term tension in relation to a stronger spring overall.

I need to re-asses my science on this. I'm not an engineer, just trying to make a strong light bridge.

The BAII bridge does do what it does because of it's mass.

The Fender benefits because of a stronger Truss Web, due to the expansion force of the spring load. Your basically making the entire bridge web stronger, and able to resist force input.

The apparent increase in resonance is due to the string vibrating more effectively against a stronger anchor point node.

It is basically brute mass versus intelligent lightweight design.

The mass and footprint of a BAII bridge does change how the bass resonates versus a vintage bridge. A lot of this can get very theory oriented, and beyond just offering a way to stiffin up a vintage bridge for better performance.