Designed a new guitar, follow the build. Alpine Spruce, Brazilian RW GF

[Joel Teel]

Originally Posted by Jeff Scott

How much does the book weight?

It's not the weight of the book, as much as the profile of its binding, that matters to the tonal nuances. 😉

[BBWW]

Sorry, weight matters to me. I don't like heavy guitars. I've always liked the mass of a maple neck however. It sounded like a heavy build to me, that's why I asked the question. I had followed the evolution of the 3 1/2 pound Breedlove as I known those guys forever.

[Joost Assink]

Originally Posted by BBWW

Sorry, weight matters to me. I don't like heavy guitars. I've always liked the mass of a maple neck however. It sounded like a heavy build to me, that's why I asked the question. I had followed the evolution of the 3 1/2 pound Breedlove as I known those guys forever.

Actually, weight can be a good thing and a bad thing depending on the location. It has been well established by many builders and many experiments that extra weight in or on the sides really increases volume, response and total top activity because you are increasing the mechanical impedance. That means the energy in the top cannot easily move into the sides and is reflected back instead of absorbed by the sides. Same goes for the neck, where you have much better sustain at higher weights. Especially at the headstock, which is why many studio players place extra weights there to increase sustain.

The other hand, the active membranes of the top and the back need to be as light as possible. Because you are on a limited energy budget, you really need stiffness, and not weight, so you need to find the optimal stiffness to weight ratio to make sure the guitar doesn't implode, but doesn't weigh so much that the strings cannot really actively and effectively move the top. Increasing stiffness while decreasing weight really just means you are making more of the energy that comes from the string, which is a given, if you consider a particular type and brand of string and a particular playing style.

If you just want to build a very light guitar, you should build it out of cedar, Spruce and mahogany, but that doesn't mean it will be any better than an African Blackwood guitar (which has a much higher specific weight and will therefore always be heavier even if built to the exact same specifications).

Actually, many think the idea of looking for a lighter guitar is sort of a myth that came out of the fact that the steel string guitar has always been a factory-built instrument, built to standard specifications, so there is a greater variation in tone because of the differences in individual pieces of wood. Finding a lighter specimen gives you a better than average chance of finding a better than average sounding instrument.

This is not specifically true for general guitar design though, as it is far more complex than that.

[BBWW]

Understood. Like many things guitar, some are personal preference. For a gigging guitar I'd gladly give up some tone/volume for less weight as the guitar will amplified anyhow. After playing all my life, a shoulder surgery, hands beginning to show the abuse of playing. I like comfort, size, reduced weight, bevels, wedges...

I have some very responsive, loud and light guitars. Some are double sided, some are not. All are small bodies.

It's just a player preference thing for me I guess and a balancing act for builders. I don't like weight pulling on my shoulder and back if I can avoid it. I'm an old guy. LOL


I'm looking forward to watching this come together.

[Joost Assink]

Originally Posted by BBWW

Understood. Like many things guitar, some are personal preference. For a gigging guitar I'd gladly give up some tone/volume for less weight as the guitar will amplified anyhow. After playing all my life, a shoulder surgery, hands beginning to show the abuse of playing. I like comfort, size, reduced weight, bevels, wedges...



I have some very responsive, loud and light guitars. Some are double sided, some are not. All are small bodies.



It's just a player preference thing for me I guess and a balancing act for builders. I don't like weight pulling on my shoulder and back if I can avoid it. I'm an old guy. LOL





I'm looking forward to watching this come together.

Ah right. This guitar is not designed to be worn on the shoulder nor amplified. You'd need a reflective back not an active back design if it's to be held against your belly and this guitar'd be much too responsive, meaning it'd be too sensitive to acoustic feedback. (Plus in my experience most people don't want to go out gigging with an expensive hand built acoustic)

[BBWW]

Originally Posted by Joost Assink

(Plus in my experience most people don't want to go out gigging with an expensive hand built acoustic)

Some of us are not that bright! :-) If I can't gig with it, even in an unplugged venue, sitting down, I don't see the point of having it. I gig even with my most expensive guitars. But that is me! Even my most road weary guitars are in great shape after 25 years of gigging. They are beautiful tools! They are art to provide art! Their beauty should be shared. That said, I don't do 180 gigs a year any longer either.

I'm enjoying your thread.

[Joost Assink]

Now all glued up with label and nice back radius!

[seminex]

Hi all,

I'm not a builder and absolutely an amateur player but i do like to learn about building process and the correlation between the design, building techniques,... and tone.
now I do understand the difference between an active and a passive back but I never understand why a active back is absolute active. when I play (maybe wrong technique) the back off hte guitar is always more or less against my body so why make an active back then?
I saw that somogy makes active backs but Ryan makes very stiff backs with an 7 degree radius, to me Ryan makes more sense OR am I missing something????

[Joost Assink]

Originally Posted by seminex

Hi all,

I'm not a builder and absolutely an amateur player but i do like to learn about building process and the correlation between the design, building techniques,... and tone.
now I do understand the difference between an active and a passive back but I never understand why a active back is absolute active. when I play (maybe wrong technique) the back off hte guitar is always more or less against my body so why make an active back then?
I saw that somogy makes active backs but Ryan makes very stiff backs with an 7 degree radius, to me Ryan makes more sense OR am I missing something????

Well that is a very good question with a complicated answer. Whether you can hear it really depends on the guitar you have, the back design and your level of playing. It could be an interesting experiment to keep your guitar horizontal, floating above your knees and just strum the open strings, then press it down on your knees and do the same thing. You should be able to hear a significant difference.


Now to answer the second part of your question, one is not better than the other, it just depends on your taste and the intention for the instrument. A reflective nonactive back is best for strumming, especially if the guitar is going to be played on a strap against your belly, where an active back would not add anything at all. All things being equal, a passive back gives you a little bit more projection and volume, where as an active back should give you a better balance and really add more complexity to the tone because the back now plays a more active part in the tone production. It also helps flatten the resonant peak from the top and even it out with the back some more.

In both cases, I suggest you try changing your playing position to keep the back away from your body, because both an active back and a passive back will lose energy to your body if they are dampened by it

[cigarfan]

Thanks Joost for sharing. This is all very interesting. I look forward to following along.

... dennis

[Joost Assink]

Today, all the sides were bent on what is probably the hottest day of the year. Two guitars with double hard wood sides means bending eight sides that are now glued together in a CNC made jig for the exact correct shape and thickness. Strong, no worries about cracking, and high mechanical impedance and stiffness to make sure the sides don't absorb energy that could be used to generate tone.

[Badcrumble]

Originally Posted by Joost Assink

I have discussed it extensively with casimi and Ryan. Both are very supportive though all in all it will be a very different beast compared to both builders. The bevel will be typical Ryan and the rosette is a variation on casimi but the rest will be very different.

I'm not sure how fair this comment is.
It looks a set of very nice guitars indeed, but in my view, not just the rosette, but the cutaway and upper bout are all very reminiscent of Casimi designs.

I think it may also be worth noting that at the time that I first came across this thread, no contact had been made with Casimi, and that Casimi initiated the conversations that followed.

[gitarro]

Originally Posted by Badcrumble

It looks a set of very nice guitars indeed, but in my view, not just the rosette, but the cutaway and upper bout are all very reminiscent of Casimi designs.

I have to say the overall look and the rosette can remind one a lot of Casimi guitars.

Having said that however, Casimi themselves have pointed to Matsuda as a strong influence design-wise, and I certainly recall the bevel around the cutaway design in particular from some of Matsuda's previous guitars, so I believe that most of the individual pieces of Casimi'a designs were not introduced by them.

I would suspect that if Uchida and Matsuda were expressly referred to every time a luthier uses a motif pioneered by them, the internet references to them would probably double at least overnight...

[Badcrumble]

Casimi guitars don't feature a bevel at the cutaway? I was referring to the shape of the bout and the shape of the cutaway, when married to the continuous purfling (I'm not sure who first did continuous purfling)

But sure, point taken, influences are everywhere.

[gitarro]

Originally Posted by Badcrumble

Casimi guitars don't feature a bevel at the cutaway? I was referring to the shape of the bout and the shape of the cutaway, when married to the continuous purfling (I'm not sure who first did continuous purfling)

But sure, point taken, influences are everywhere.

BTW I'm not discounting the creativity and imagination it took for Casimi to come up with their overall "look".

Even though the individual components may be borrowed from elsewhere, the overall look can still look distinctive.

On the bevels around the cutaway and flowing into the soundhole, I was referring to for example the following:-


http://www.dreamguitars.com/sold-gui...matsuda_m1_50/

https://www.google.com/search?q=mich...GQUgrwHGOGM%3A

http://symphontreemusic.com/portfolio/casimi-guitars/