2014 Shopis D’Artagnan Model S | Blog

paulmcevoy75 · February 25

Oddly enough I was just doing acoustic testing on a set of redwood someone gave me last night.

Density 383,3 (kg/mCubed) L

Q 212,6 V High

Young's Modulus 9,4 L

Sound Radiation coefficient 12,9 H

That's roughly in range with Redwood

For contrast, Spruce from my personal guitar:

D 439,1H

Q 163,6 H

YM 14,4 H

SRC 13,1 H

(Q is a measure of how much damping the wood has naturally. High Q=Low Damping)

Young's Modulus is a measure of the stiffness of the wood

Sound Radiation Coefficient measures the "loudness" of a material

I'm kinda new to this sort of testing but I think this shows that Redwood is in general much lighter than Spruce. It has extremely low damping, that's off the chart for Spruce. It is not very stiff at all, the YM is lower than every sample of Spruce I have. The SRC is about the same as really good spruce.

I may have accidentally been gifted really exceptional Spruce...I'm not sure what the averages are there.

Anyway, I would guess from these purposes that a Redwood top looks great in general, it is much less stiff than a Spruce top so either would need to be thicker, braced heavier or it would be a worry about its structural health overtime.

I'm not sure exactly how its very low damping effects the sound specifically, it would mostly be very positive but could also make a more unpredictable wolfy instrument potentially.

As far as using Cedar or Redwood all the time, I think (!) in the classical world there's the idea of "Spruce wearing in, Cedar wearing out". Whether that is true or not I'm not sure, I think there is a lot of disagreement there. I have a classical guitar friend in Montreal who concertizes a lot and has two really high end classical guitars by the same maker, one spruce and one cedar and TBH they sound way more alike than they do different. Almost identical.

I sort of think that it's probably easier to build a great sounding cedar guitar than a great sounding spruce guitar, and so for factory instruments, cedar is going to win. There's a lot going for it in a production sense, and if you are building mildly heavy factory instruments, the cedar is going to definitely sound better if the spruce and cedar tops are the same thickness because it's massively lighter. When you are talking luthier made instruments, I imagine that the differences probably become less apparent. And if you are comparing used instruments that have been around for a bit, the differences might become even less pronounced.

Just my opinions, genuinely worthless....

This is all in the abstract and listening to the actual instrument is obviously where the proof of the pudding is. Just thought it might be interesting.

pdg · February 25

I had fantastic redwood once. Another time we cut redwood from another source and it had such low stiffness that it was unusable. Depends on whether it's from fast growing younger trees, older trees, etc. But if a good luthier likes his/her stash, it's probaby good.

paulmcevoy75 · February 25

https://www.djangobooks.com/forum/discussion/comment/124526#Comment_124526

it seems pretty brittle to me, in the sense that it feels like it might split pretty easily. As in...I split the piece I was testing while just flexing it a little bit. That's not desirable to me...

MichaelHorowitz · February 25

As far as using Cedar or Redwood all the time, I think (!) in the classical world there's the idea of "Spruce wearing in, Cedar wearing out".

@paulmcevoy75 Favino made a number of cedar top guitars in the late 70s. These are probably the first Gypsy guitars to ever have been made with cedar tops. They’re now over 45 years old and I’ve always found them to be some of the best sounding Favinos. If cedar “wears out,” it must take a lot longer than half a century.

here’s one that came in recently:

https://www.djangobooks.com/Item/jean-pierre-favino-549

flaco · February 25

When I got my redwood guitar and went back and looked up some of the old threads where it had been discussed. This one has Craig Bumgarner and Bob Holo discussing spruce vs. cedar vs. redwood. Probably very important to the luthier, but I think for the buyer/player all that matters is whether you like the sound of an individual guitar.

https://djangobooks.com/forum/discussion/12398/gj-cedar-tops-and-quot-new-school-quot?srsltid=AfmBOopJhUzZ_1hZHnQyEMuJpHt3-0bHzNc0tagWFLlOylfoZ81kUtHw

paulmcevoy75 · February 25

https://www.djangobooks.com/forum/discussion/comment/124528#Comment_124528

yeah to be clear I was just saying that seems to be the conventional wisdom.

Just wondering then, do you just prefer cedar guitars in general? They are sort of rare birds in the gypsy world?

MichaelHorowitz · February 25

https://www.djangobooks.com/forum/discussion/comment/124530#Comment_124530

I’ve owned both, ultimately it just depends on the individual instrument. However, the difference of a new cedar vs new spruce guitar is not subtle. The cedar is so responsive from the get to, hard to put it down!