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First build- The physics of 24 frtes?
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Author:  HNS [ Wed Oct 03, 2018 1:17 am ]
Post subject:  First build- The physics of 24 frtes?
Greetings everyone [uncle] [uncle]
I'm new here and on my quest to build my first electric guitar. I tried a few years back but never took the project forward.

I've heard and experienced the neck placement on 24 fret guitars, and that it's not at a node, its quarter way to the antiNode and how that would affect tone by cancelling certain frequencies making the tone thinner compared to placing the pickup at the node (given the humbucker actually picks up a range of frequencies, not just the nodal conflux). For me, 24 fretters are thinner, lower in the low midrange, but clearer compared to the more traditional thicker sounding neck placement associated with 22 or 21 fretters. But they lack volume (I also saw Ed Romans opinion on this).

Can someone please explain this or show me where I could get some info here.
Cheers
HNS
Author:  B. Howard [ Wed Oct 03, 2018 5:04 am ]
Post subject:  Re: First build- The physics of 24 frtes?
so let me ask you this.....what happens when you play say an F chord? Where are the nodes? They all moved! Why? Because speaking length of the string has changed the second you fret any note.....the nodes are formed only by the vibrating length of the string.


Basically the math works like this.... 25.5" scale and you are concerned about the quarter node so we will look at that. 25.5/4= 6.375. So when played open we have a node 6.375 inch from the face of the saddle.

Now let's fret the 3rd fret which shortens scale by 3.58" so now we have 21.92 and 21.92/4= 5.48. So our quarter node is now .895" closer to our saddle. If we move up a whole 5th and fret the 7th fret our node moves to 4.5 inches from the saddle face.....

Now compound that by the fact that when we play a chord every string will have it's node at a different point on the string.... They simply no longer line up with eachother across the strings, so how does that work with your theory? If what you are saying is true then the dynamics should change wildly from chord to chord and even on the same chord by playing it at different positions on the neck. But that doesn't seem to be the case does it?
Author:  HNS [ Wed Oct 03, 2018 10:16 am ]
Post subject:  Re: First build- The physics of 24 frtes?
Thanks Brian

I don't actually have a theory yet, I'm trying to put neck pickup placement between 24 and 22 fret guitars in perspective. What I do experience is that 22 fretters are more robust sounding while 24 fretters are thinner, brighter but clearer. There are many theories on the net as to why I just need experienced hands on this matter to shed light. I grew up playing 22 fret guitars, I only began seeing the 24 frets in the 1980's.
Cheers
H
Author:  Conor_Searl [ Wed Oct 03, 2018 11:12 am ]
Post subject:  Re: First build- The physics of 24 frtes?
Take all this with a grain of salt, I'm in the same place as you are. But I have played a lot of guitars over the years. Have you played 24 and 22 fret guitars that are as much the same as possible in regards to everything but the extra two frets to make that comparison, or are you stacking a Jackson up against a Gibson? I think first and foremost different pickups will cause a much bigger difference to amplified tone than two extra frets, then you have the type of wood the body is made of, how the neck is joined to the body, the string break angle at the bridge, scale length, there are so many variables that play into the end result.

My personal philosophy when it comes to guitar designs is that every guitar is a set of specific limitations for the guitarist, and those limitations influence in unique ways the way a person interacts with the guitar. All that is to say that many design features are trade offs, someone can't say that Fender's 25.5" scale length is definitively better than Gibson's 24.75", they're just different. In my experience there's no such thing as the perfect guitar, and musical equipment that try's to do everything typically doesn't anything very well. So my advice would be if you use the 23rd and 24th fret, and want to incorporate that into your design go for it, and revel in the opportunity's provided by the extra two notes.

As far as where to place the neck pickup, there's only so much real estate between the bridge and neck, and I tend to agree with Brian. Every time you play in a different place on the fret board you will be changing where those nodes appear. So spending a lot of time worrying about them will likely only matter if you plan on limiting yourself to playing in the keys that work ideally with where your pickup is placed. Rather I'd find some examples of 24 fret guitars that you really like and start with where they placed their neck pickup. Then once your done building this guitar start on the next one and tweak it. :)
Author:  Freeman [ Wed Oct 03, 2018 11:20 am ]
Post subject:  Re: First build- The physics of 24 frtes?
There happens to be a discussion on a similar topic at another forum right now

https://www.harmonycentral.com/forum/fo ... e-position

I think you can learn a lot by comparing the neck and middle pickups on a three p/u guitar, as well as contemplating the effect of slanting the bridge pup. Many people claim that the slant makes the high strings brighter, the low strings darker - I had a customer a couple of weeks ago ask about reversing the slant on his tele.
Author:  B. Howard [ Thu Oct 04, 2018 12:23 pm ]
Post subject:  Re: First build- The physics of 24 frtes?
A few more thoughts.

The fact that a node is a point on the string that does not move relative to its normal axis.... the string moves in between the nodes. So having a pick up that senses string motion directly at a stationary point of the string would not be optimal.

Also there is the sensing width of any given pickup. This is determined largely by the magnetic field which cannot be seen or even readily measured to get a baseline for comparison. A humbucker has two sets of poles projecting one end of the field each centered about 1 inch apart, so which would even see the node? Even a single coil does not create a razor thin magnetic field and still will sense an area wider than the actual pick up depending on magnet strength.

This rabbit hole seems to trace back to one player in particular as it's genesis, I've heard this theory before. And my opinion is said player should stay to wowing with his chops and let the lutherie to the luthiers.... ;)
Author:  HNS [ Thu Oct 04, 2018 2:36 pm ]
Post subject:  Re: First build- The physics of 24 frtes?
Thank you all for your comments .... so the 24 fretters sound thinner just "mainly" because the pickup is 3/4" closer to bridge (other things equal)?

Cheers
HNS
Author:  Conor_Searl [ Thu Oct 04, 2018 5:39 pm ]
Post subject:  Re: First build- The physics of 24 frtes?
I'd say the "thinner" you're hearing is primarily the difference in pickups more than it is the placement of the pickup. If I plugged a Les Paul (22 frets) with PAF style humbuckers into a Marshall, and then plugged a Jackson Soloist (24 frets) into the same amp without tweaking anything I bet the Jackson would sound thinner, but that difference in tone would be the result of a lot of variables, most of which I'd take into consideration before worrying about the placement of the pickup.

I think PRS makes comparable models that have 22 and 24 fret necks, maybe playing some of those side by side will give you a clearer idea of the practical differences...
Author:  Freeman [ Thu Oct 04, 2018 9:10 pm ]
Post subject:  Re: First build- The physics of 24 frtes?
HNS wrote:
Thank you all for your comments .... so the 24 fretters sound thinner just "mainly" because the pickup is 3/4" closer to bridge (other things equal)?

Cheers
HNS


If you look at that link I gave you, the last post (as of today) is kind of interesting. Someone hollowed out a tele and put a rail in it (looks like DIN rail) and mounted a single humbucker so it could be moved from near the bridge to near the neck. He offers no supporting sound clips or results of any study but it would be an interesting way to see what differences you could detect.

Otherwise I would have to base my response on the fact that if I change the location that I pluck a string from the bridge to the neck (or beyond) I know I get a different sound. A good classical player uses this to color their tone, an electric player thinks of rhythm or lead. I also know that a magnetic pickup is sensitive to the strings right in front of it, whatever mixture of fundimentals and harmonics. If I play a string (acoustically) fretted at different places and pick at different places I should be able to find whatever I think is the sweet spot and position the pickup accordingly. Unfortunately you can't do that on a guitar with the pickup already located - that negates the premise. And of course most electric guitars don't sound very good acoustically. Catch 22.

I'm going to add that I build mostly 22 fret guitars with humbucking pickups as close to the end of the fretboard as I can get them. I have no need for 24 frets and I doubt if I could hear the "thinner" sound you are describing.
Author:  HNS [ Fri Oct 05, 2018 1:56 am ]
Post subject:  Re: First build- The physics of 24 frtes?
Thanks Conor_searl and Freeman
I played the PRS 22 vs 24 both with the same pickups and there was a difference in tone (the thinner sounding aspect i heard), especially if you don't tweak the amp or eq it just as you said Conor, but these could be my old ears. In addition, there was also a more nasal sound that was not related to lesser lower mids or anything, but I attributed that to the neck pup placement (at least I thought so), but again they may be just the differences related to those particular guitars. I'm newbie here.

Freeman, that rail guitar would answer it no doubt, I'll see youtube maybe someone put a clip up there sometime. It's really interesting because that eliminates many variables that could affect the comparison.

Thanks a million folks. It's much appreciated
HNS
Author:  HNS [ Fri Oct 05, 2018 2:04 am ]
Post subject:  Re: First build- The physics of 24 frtes?
There are a few, they are, not perfect tests but interesting ....Thanks Freeman for the tip.

https://www.youtube.com/watch?v=YUJ1-LKXs-c

https://www.youtube.com/watch?v=MS02YaLw1uM

https://www.youtube.com/watch?v=cwNebC08S50

https://www.youtube.com/watch?v=zxULNwyQKX8

https://www.youtube.com/watch?v=EPpvDA1XDwA
Author:  Freeman [ Fri Oct 05, 2018 11:00 am ]
Post subject:  Re: First build- The physics of 24 frtes?
HNS wrote:
There are a few, they are, not perfect tests but interesting ....Thanks Freeman for the tip.


I love the Leggo wheels and drum sticks
Author:  Conor_Searl [ Wed Oct 24, 2018 11:56 am ]
Post subject:  Re: First build- The physics of 24 frtes?
I found this comparison... https://youtu.be/8TCnptoc2yo

There's definitely a slight tonal difference. I thought the 22 fret guitar sounded a little more even across the frequencies, while the 24 fret had a bit more of a scooped sound. But to my ear I preferred the 24 fret guitar, I thought it sounded warmer.

I don't know anything about nodes, but I see now that the neck pickup being that much closer to the bridge would definitely change the amplified sound. Much like how the middle pickup on a strat has a very different sound than the neck pickup.
Author:  MythicGuitars [ Mon Jan 07, 2019 10:07 pm ]
Post subject:  Re: First build- The physics of 24 frtes?
B. Howard wrote:
so let me ask you this.....what happens when you play say an F chord? Where are the nodes? They all moved! Why? Because speaking length of the string has changed the second you fret any note.....the nodes are formed only by the vibrating length of the string.


Basically the math works like this.... 25.5" scale and you are concerned about the quarter node so we will look at that. 25.5/4= 6.375. So when played open we have a node 6.375 inch from the face of the saddle.

Now let's fret the 3rd fret which shortens scale by 3.58" so now we have 21.92 and 21.92/4= 5.48. So our quarter node is now .895" closer to our saddle. If we move up a whole 5th and fret the 7th fret our node moves to 4.5 inches from the saddle face.....

Now compound that by the fact that when we play a chord every string will have it's node at a different point on the string.... They simply no longer line up with eachother across the strings, so how does that work with your theory? If what you are saying is true then the dynamics should change wildly from chord to chord and even on the same chord by playing it at different positions on the neck. But that doesn't seem to be the case does it?


What was said is correct, however I don't know many people who strum chords on a 24 fret. Most people play arpegiated scales and bar chords in drop D with teeth shattering gain and distortion while slinging their hair around their heads violently while playing one. So playing style and electronics with screamo ceramic magnets has something to do with it too I'd wager. Lolol

With that said.. I learned something by reading this.
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