Neck Joints

[Wellington]

I find neck joint topics interesting, it seems like they're a little mysterious in what the do or do not contribute to tonally. My beloved Guild is a dovetail, though some of the U.S.A models are mortise and tenon, depends which model you buy now.
I've had bolt on as well, no idea what my LL16 is, I've also owned and still own epoxied joints, set initially with a bolt during dry time. Those suck, avoid those is all ill say, and that's Godin that does that.

Other than that, I'm somewhat unphased by neck joints. If I like the guitar then I like it, as long as it can be repairable if it were to need a neck reset is my only criteria.

I'd like to say a dovetail is a more solid and sure method but Martin continually proves that wrong. I think it has less to do with the joint and more to do with other factors regarding a reset.

It would be interesting to see some builders or repair techs speak up about whether a dovetail or M&T is easier to reset.

[cliff_the_stiff]

Most have said that there is no tonal benefits between the differing joints. I disagree. I think the wood joints vs bolted joints make fuller sounds. In extreme comparison, pick bright guitars and bright woods like a Taylor 614, and a Gibson J185 and play them back to back and both sound fantastic, but the Gibson just has more character or something. I think it’s the neck joint.
In similar discussion here last week someone posted the faq from SCGC about necks and such. It was Richard Hoovers opinion that everything down to the density of the woods and the weight of the tuners would have a contribution to the tone.

[rstaight]

I have seen videos where set dovetail neck joints are converted to bolt on.

Most of them were so bad a bolt on made more sense. Other's I think were done because they thought it was easier.

[jim1960]

Originally Posted by cliff_the_stiff

In extreme comparison, pick bright guitars and bright woods like a Taylor 614, and a Gibson J185 and play them back to back and both sound fantastic, but the Gibson just has more character or something. I think it’s the neck joint.

How did you rule out all the other variables that could account for tonal differences between those two guitars and conclude that the neck joint was responsible?

[jmjohnson]

I lean towards the dovetail because it traditionally symbolizes a higher "standard" in my Martins, and the Gibsons and past-owned Guild have/had it.

But IF I was worried about getting a neck reset - I'd be wishing they had a Taylor NT joint.

Same thing with finish - lean towards nitro, but man it is a bit more comforting when some strange goo gets on the Taylor knowing it has poly.

[Malcolm Kindnes]

Originally Posted by Troubador

What about durability, though? Is any one better than the other(s)?

I don't think durability will be affected at all. I have a friend who is a luthier who has used both methods with equal success.

[s2y]

I have several bolt-on acoustics that have phenomenal tone. Will they be easier to reset? Probably. One thing to keep in mind is to keep the top adequately hydrated to hopefully slow down the reset process to a certain extent. I live in an area with 2 big humidity changes per year. Enough expansion and contraction can pop a brace and the top starts to lose integrity.

[cliff_the_stiff]

Originally Posted by jim1960

How did you rule out all the other variables that could account for tonal differences between those two guitars and conclude that the neck joint was responsible?

I was imagining a hypothetical.
I picked two maple backed guitars I’ve personally owned with a 16 inch bout and different neck joints. since this is not a thread about bracing I focused on the neck joint.
I referred to Richard Hoovers opinion that everything impacted tone including the weight of the tuning machines, I figured that I covered the “other variables” disclaimer.
Since this question is subjective, it’s my opinion that the dovetail or mortise and tenon joints will allow more wave transference than a bolt on based on physics.

[ProfChris]

Originally Posted by Troubador

Thanks for the info. I thought a mortise and tenon was easier to reset than a dovetail, based on some things I've read.

Most bolt-ons have a mortice and tenon, which makes a reset much easier if the joint isn't glued.

Glued mortice and tenon joints are harder to release than dovetails. To release a glued joint you have to soften the glue, and then ease the joint apart. Once the dovetail starts to rise up, the dovetail sides (where the glue is) lose contact with the pocket, and you've won. In an M&T joint the tenon sides are still in contact with the pocket all the way up, so it can be a struggle all the way as the glue fights to keep the tenon attached.

[pagedr]

Originally Posted by Troubador

And I would do that, too, but affordability would be an issue with me.

Man if finances are that tight maybe just consider setting aside like $3/month to a "repair fund". After 15 years that would be over $500, enough to cover a neck reset at many repair shops. Or as someone else said, if even that isn't feasible, maybe consider something on the cheaper end of the spectrum.

[jim1960]

Originally Posted by cliff_the_stiff

I was imagining a hypothetical.
I picked two maple backed guitars I’ve personally owned with a 16 inch bout and different neck joints. since this is not a thread about bracing I focused on the neck joint.

If it were a thread about bracing, couldn't you have just as easily claimed that the difference in bracing accounted for the difference in tone?

Originally Posted by cliff_the_stiff

I referred to Richard Hoovers opinion that everything impacted tone including the weight of the tuning machines, I figured that I covered the “other variables” disclaimer.

If you agree that everything influences tone, I don't understand how you just arbitrarily discount the other variables and claim the difference is due to the neck joint.

Originally Posted by cliff_the_stiff

Since this question is subjective, it’s my opinion that the dovetail or mortise and tenon joints will allow more wave transference than a bolt on based on physics.

I agree the issue of how much influence a neck joint has on a guitar is subjective ...but that's because it's very difficult to demonstrate. To do so, one would have to build a guitar that could be switched from a dovetail joint to a bolt on joint without changing anything else on the guitar. Additionally, it would have to be done in a controlled environment where the temperature and humidity were controlled. Also, the guitar would have to be played by a machine to recreate the exact same pressure and angle for the pick on the strings. And speaking of strings, some attention would be needed to ensure that the strings used in the experiment weren't the cause of any tonal changes.

Like I said... difficult ...and impossible for any of us to pull off in our living rooms.

Here's my point...
I agree with the basic premise you assign to Hoover that everything effects the tone of a guitar. However, not everything effects the tone of a guitar to the same degree.
Top wood, for example, has a tremendous effect on the tone.
The weight of a screw holding a tuner in place also has an effect but the effect will be imperceptible unless you're using highly sensitive scientific equipment to measure the difference.

Any two guitars are going to have dozens of variables. You can't simply say the back wood is the same and the width of the lower bout is the same, therefore, the tonal difference is due to the guitars having different neck joints. Even if we just look at the back wood on your two guitars, we're going to find variables that could account for tonal differences... different thickness, cut from different trees that grew in different places, different tap tone, etc.

The other problem with your assertion is sample size. You're making a sweeping assertion based upon a sample size of two. You mentioned "physics" in your response but there's nothing scientific about your conclusion; it's simply a guess.

[cliff_the_stiff]

Originally Posted by jim1960

The other problem with your assertion is sample size. You're making a sweeping assertion based upon a sample size of two. You mentioned "physics" in your response but there's nothing scientific about your conclusion; it's simply a guess.

Well, I won’t argue that I wasn’t oversimplifying what makes a good guitar. I was. Regarding physics, it’s not a guess, the theory is observed in simple experiments.
Waves: Take a length of rope and create a wave with it.
Next tie a knot in the rope. Now create the same wave and the wave will behave differently when it hits the knot. (or has the knot now created a fixed node?) Add more mass to the knot by tying some bolts into the knot, the wave will have even more trouble traveling through the increased mass at the same pace.
The nodal locations will determine the maximum wavelengths and impact focused overtones.
from the SCGC website: https://santacruzguitar.com/faq/

Q: Why does SCGC use a dovetail jointed neck instead of a bolt-on neck?
A: Dovetail joint is an integral connection between the neck and the body. The counterpart is a bolt-on neck. Both function mechanically well – bolt-on is easier, advantageous to the manufacturer as it requires less skill, is cheap to do and takes less time. They say it is a great advantage to the end user as the neck can come off quickly for repair, and that you have to rip a guitar apart to take off a dovetail jointed neck, but this is not so. If a dovetail neck wasn’t superior sonically, we wouldn’t do it. We voice and tune our instruments to be very responsive. The dovetail jointed neck allows us subtle degrees of control to give the guitar the optimal presence to sound its best… it’s like a laser beam as opposed to a flood light, or clean, clear and precise vs. open, airy, friendly and blended. A trick that we use to control getting these different sounds is to either allow vibration from the strings/body to chimney up the neck or to block it. This is done by manipulating the density of the wood in the neck, using heavier gears or a larger peghead, which blocks vibration up the neck and gives guitar more focus. The opposite is a slotted peghead, light open back gears and less dense wood in the neck; this allows vibration and gives a more open, airy ambience. The Dovetail neck facilitates that, allows focus or vibration freely, whereas the bolt-on neck is already adding mass in addition to the wood and doesn’t allow for this trick. By design, the dovetail joint is accessible – simply by removing the fret above the body joint towards the sound hole, we can drill a hole and inject steam into it, which melts the glue and allows for easy removal for repair. A dovetail neck, by nature, is strong enough to hold string tension… just a little glue is used, so facilitating the repair is a straightforward process. We take extra time, expertise and money to make these necks, as it is extremely beneficial to the customer.

[EZK123]

Originally Posted by jim1960

The other problem with your assertion is sample size. You're making a sweeping assertion based upon a sample size of two. You mentioned "physics" in your response but there's nothing scientific about your conclusion; it's simply a guess.

I'd have to agree. Making an absolute assertion based on a sample group of two and only one variable between the two samples is pretty specious reasoning. I mean. . . you could take two presumably identical guitars from the same manufacturer and hear an obvious difference between the two. Take two new D-28s (for example) and after playing both for a while, many (if not most) people would have a preference and would be able to tell the difference between the two.

Taking two different guitars made at different times from different wood (of the same species even), using different bracing patterns, different bridge design, all the way down to different tuners, different fret wire, different adhesives and different finish, then claiming that the audible difference between the two was because of the neck joint is pure assumption and guesswork with no tangible evidence to support it.

[jim1960]

Originally Posted by cliff_the_stiff

Well, I won’t argue that I wasn’t oversimplifying what makes a good guitar. I was. Regarding physics, it’s not a guess, the theory is observed in simple experiments.
Waves: Take a length of rope and create a wave with it.
Next tie a knot in the rope. Now create the same wave and the wave will behave differently when it hits the knot. (or has the knot now created a fixed node?) Add more mass to the knot by tying some bolts into the knot, the wave will have even more trouble traveling through the increased mass at the same pace.
The nodal locations will determine the maximum wavelengths and impact focused overtones.
from the SCGC website: https://santacruzguitar.com/faq/

You're misunderstanding what I'm saying. I'm not arguing that there is no science involved in the building of a guitar, including the neck joint. I'm saying you're not making a science-based argument because you have no way of accounting for the dozens of variables between your two guitars. In other words, you can't say the laws of physics that determine what effect a neck joint will have on tone matters but the laws of physics regarding every other variable do not.

Originally Posted by cliff_the_stiff

Q: Why does SCGC use a dovetail jointed neck instead of a bolt-on neck?
A: Dovetail joint is an integral connection between the neck and the body. The counterpart is a bolt-on neck. Both function mechanically well – bolt-on is easier, advantageous to the manufacturer as it requires less skill, is cheap to do and takes less time. They say it is a great advantage to the end user as the neck can come off quickly for repair, and that you have to rip a guitar apart to take off a dovetail jointed neck, but this is not so. If a dovetail neck wasn’t superior sonically, we wouldn’t do it. We voice and tune our instruments to be very responsive. The dovetail jointed neck allows us subtle degrees of control to give the guitar the optimal presence to sound its best… it’s like a laser beam as opposed to a flood light, or clean, clear and precise vs. open, airy, friendly and blended. A trick that we use to control getting these different sounds is to either allow vibration from the strings/body to chimney up the neck or to block it. This is done by manipulating the density of the wood in the neck, using heavier gears or a larger peghead, which blocks vibration up the neck and gives guitar more focus. The opposite is a slotted peghead, light open back gears and less dense wood in the neck; this allows vibration and gives a more open, airy ambience. The Dovetail neck facilitates that, allows focus or vibration freely, whereas the bolt-on neck is already adding mass in addition to the wood and doesn’t allow for this trick. By design, the dovetail joint is accessible – simply by removing the fret above the body joint towards the sound hole, we can drill a hole and inject steam into it, which melts the glue and allows for easy removal for repair. A dovetail neck, by nature, is strong enough to hold string tension… just a little glue is used, so facilitating the repair is a straightforward process. We take extra time, expertise and money to make these necks, as it is extremely beneficial to the customer.

Can SCGC show us empirical evidence for this claim? I understand whoever wrote that has an opinion, and it may even be a correct opinion, but unless it can be proven, it has no more weight than a builder who argues a contrary opinion and everything in the "answer" you quoted is nothing more than marketing copy. You can't bring science into this and then toss the scientific method out the window.

[Sadie-f]

First, at this level, we're way beyond the scope of the OP's topic, however:

Originally Posted by jim1960

You're misunderstanding what I'm saying. I'm not arguing that there is no science involved in the building of a guitar, including the neck joint. I'm saying you're not making a science-based argument because you have no way of accounting for the dozens of variables between your two guitars. In other words, you can't say the laws of physics that determine what effect a neck joint will have on tone matters but the laws of physics regarding every other variable do not.

...
Can SCGC show us empirical evidence for this claim? I understand whoever wrote that has an opinion, and it may even be a correct opinion, but unless it can be proven, it has no more weight than a builder who argues a contrary opinion and everything in the "answer" you quoted is nothing more than marketing copy. You can't bring science into this and then toss the scientific method out the window.

I think questioning whether SCGC would publish that without foundation is a bit of a stretch, and @cliff's discussion of the effects of discontinuities in a vibrating structure is spot on. As for putting weight in the words of this or that builder, well I'm an engineer specializing in material science.

I have listed to various luthiers talk about technical aspects of guitar design and effects on sound. I don't doubt that anyone who's building customs at the level of SCGC, or any of the shops that tap-tune top and back do fully understand what they're doing. Many, however pretty clearly do not have a solid understanding of the underlying math & science, and some pretty clearly do.

I happen to believe the SCGC design approach on their neck joint. I also *think* the mass of the connection is probably lowest using a dovetail joint. This said, I'm also impressed with Howard Klepper's designs, and he holds that a bolted joint can be made to an equal quality as a dovetail (subject to using optimized fasteners etc).

However Klepper is also quite clear on the impact of individual pieces of wood in a guitar construction: this is the reason tap-tuning makes such a difference in construction, if all sections of sitka, or Adi spruce, or whatever grade of rosewood, mahogany, etc were identical, then these parts could be pre-cut to an exact design, however they're not.