Official Luthiers Forum!

Hi everyone,

I am about to embark on building my first guitar, with the guidance of the Cumpiano book that we all know so well.

It will be a classical guitar. I am looking for a warm sound, not nasal or thin. Something you would get from a cedar top.
But, I want to use a spruce top. So my idea is to balance the spruce with cedar braces etc...

Materials list-

1. back and sides - Black Walnut - just purchased on ebay (crossing my fingers, seller had 100% feedback)
2. Neck - spanish cedar, possibly with a carbon fiber rod (working a practice neck now made out of Home Depot poplar)
3. Endblock - spanish cedar
4. Kerfing - spanish cedar (will purchase premade) should I use Western Red Cedar here ? or rather can I use Red Cedar here? any advantage to either ?
5. braces on top and back - should I use Western Red cedar ? - OR Spanish cedar ?
6. top - Engleman Spruce
7. bindings and purfling (curly maple, and marquetry pattern for purfling)
8. Back interior support strip - spruce
9. bridge pad - made from soundboard cut off - E. Spruce
10. headstock vaneer - Black walnut made from cut offs.
11. Bridge and fretboard - E.I. Rosewood, or Madagascar ebony

Any ideas ? does my idea of balancing a spruce soundboard with cedar interior make sense ?
Any other tips ?

Thanks
John

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It's this new idea from recent decades that everyone gets a participation award. - MUX

The Cedar bracing will not give the Spruce the ring tone of Cedar. The bracing can and will affect tone but the weight to strength ratio of Cedar as compared to most Spruce is significant. So for Cedar to provide the same section modulus through a given cross section, Cedar will need to have more mass.

I am not saying you can’t tune a spruce top produce a warm response. just that Cedar bracing is to the magic bullet to get it done. Also I do suspect that to do so you are likely to loose some of the sparkle on the high frequencies

Just for curiosity what is your reasoning for not using Cedar if Cedar tone is what you are looking for?

Redwood top is another good choice for a dark or warm tone. Yes even on a classical.

Thanks -

I have a spruce and a cedar guitar now. The spruce gives me a good tone - plus I really like the crisp look of spruce on a darker tonewood like Walnut.
My second guitar will probably be cedar - let's see how the spruce/walnut turns out....

are the materials I selected still ok? regardless of it not being able to soften the spruce sound ?


although - thinking about it - maybe a cedar soundboard with curly maple bindings may look really good too.... the binds will pop out nice on cedar and walnut. I would then change all my brace wood to spruce - just to have some contrast inside the box.

Thanks,
John

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It's this new idea from recent decades that everyone gets a participation award. - MUX

Walnut & Cedar !
A magical combo .
Use the premade Sp.Cedar kerfing because you can get it very easily and it smells so good.
Also it's a bit tougher(stronger) then Red.




9. bridge pad - made from soundboard cut off - E. Spruce-
do not make this more than 2mm thick .


Any ideas ? does my idea of balancing a spruce soundboard with cedar interior make sense ?
YES!!
Any other tips ?

Yes it's a way to voice a guitar using wood weights & stiffness.


Cedar bracing is fine for the fans.
I'd stick with spruce for the transverse braces above & below the sound hole.
Cedar will work there but it does not hold a glue joint as good as Spruce does.
If the guitar was to get a good whack to the top the cedar braces may let go -more than a spruce one would.

Get to making it !

Mike

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Mike Collins

Outside of bracing I have no issues with you materials. reall wuld like to talk you into Spruce bracing.


I am not a fan of Wanut on classical guitars but that is only a personal opinion. many classicals have used Walnut.

The problem from my point of view is that you're starting off on nearly the wrong foot. It's a bit hard to explain in one post on a 'board, but I'll see what I can do.

'Warmth' is one of those tricky descriptors. Usually it's taken to mean a sound with a lot of low end, but I think it's more complex than that. Low end by itself usually sounds 'tubby' to me. It seems to me that for a really 'warm' sound you need that low end plus a lot of higher overtones. Your ear assigns the energy from those overtones to the fundamental, and that helps to 'fatten up' the sound, particularly if the high end peaks in the spectrum are well defined, with 'dips' in between, which makes things 'interesting'.

The way you get that sort of spectrum is to reduce losses in the wood. The 'warm' sound of rosewood has a lot to do with it's long 'ring' when tapped, a sign of low losses. Cedar also tends to have lower losses than spruce, and I think that has more to do with the 'warmth' of it than it's low density. I'll note that one of my recent classicals has a redwood top that is as dense and stiff as most spruce, but it also has notably low losses, and the guitar has the sweetest and clearest trebles of anything I've made.

That guitar, BTW, has walnut B&S. That was a deliberate pairing: I've found that most of the spruce/walnut classicals I've made have been overly 'bright' and 'forward'. I attribute this, in part, to the low density and rather high losses of the walnut, which gives the guitar a lot of 'punch' without a lot of sustain unless something is done to compensate. (Yes, I know I said the low losses of rosewood contribute to warmth, and now I'm saying that high losses in walnut contribute to 'brightness': I told you it was complicated. It has to do with the pairing of density and loss factor)

Engelmann spruce is often low in density, and can have reasonably low losses, but it varies a lot. I've got Engelmann tops that have a lengthwise Young's modulus (E) of around 8000 megaPascals, with a density of 360 kg/cubic meter, and others that are at 500 kg/m^3 with Elong around 17000 mPa. The low end ones are right in there with the lightest cedar, and the high end ones are more like dense Red spruce. The irony is that I got the dense ones when I asked a supplier to send me their lightest tops: they're all sanded thin, so...

Anyway: try to figure out what the density of your top is. One way is to wrap it in a plastic bag and put it in the water endwise. Mark how deep it floats: if 40% of it is in the water, the specific gravity is .4, and that's a density of 400 kg/m^3. One of the nice things about metric... If it's at the low end of the scale, below .4 sp.g., then I'd leave it about 10% thicker than C&N tell you to, and go from there. If it's light and rings a long time when it's tapped, then you might end up with the sound you want.

Oh yeah: use the spruce bracing.

ok -

so I will use spruce bracing -

Alan thanks for the feedback - as well as the advice from everyone else... I think I will now go with Cedar then as it will be much easier to get the sound I want, and I will have all spruce bracing.
Thanks to Mike Collins enthusiastic reponse I am leaning toward his advice.


Anyone else have thoughts on this ? Attached is the back and side set I just bought.

Any pictures out there of Walnut and Cedar guitars ? Walnut and Spruce ?

Thanks !

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It's this new idea from recent decades that everyone gets a participation award. - MUX

I love the symmetry of the figure in that set. Don't use a center purfling! At least that my opinion. I love the color as well

Beautiful set of walnut! Very similar to a set that I used for a Walnut - Red Cedar steel string. I won't give you any advice on building your classical, because I know next to nothing about building clasiscals. but I really like the walnut/cedar combo for my 000 sized steel string. The cedar was wide open from day one...

Oh, well, maybe one bit of advice. Cover the soundboard with a caul as soon as you can - cedar is much more fragile than spruce - really easy to put a divot in that top.

Enjoy!

Alan, can you compare walnut to maple?

Thanks.

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Build log

I'm in the final stages of making my first guitar, so I can't comment on your choice of materials, but I wholeheartedly commend your "working a practice neck of poplar".
I tried most of the operations on scrap wood first, and even made an ebony practice fretboard before making the actual one. I made most of my mistakes on the "practice" pieces, and learned a lot.

Ray

In terms of measurable properties, such as density, Young's modulus along and across the grain, and damping, soft (European) maple and walnut are very similar. I tend to think of the sound as similar as wel, except that walnut seems 'darker' to me: maybe I'm hearing with my eyes on that, though. As always, there's a lot of varioation in any species, so the only way to be sure is to measure. Rock maple is a lot harder and denser, and might lean a little toawrd the 'rosewood' camp.

After reading these posts, I am very tempted to make a flamenco with spruce top and walnut B&S. Minimal sustain, high volume, brassy...might be very cool....Thanks!

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John Nowicki