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Old 08-28-2017, 08:28 AM
Dan of SC Dan of SC is offline
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Default sitka vs adirondack

I'm an amateur builder, having built 5 guitars, 2 mandolins, 2 ukes, and 1 octave mandolin, over a period of about 4 years. The first 3 guitars have sitka tops, the last 2 have adirondack tops. The sitka tops have very tight lines, indicating old growth to me. The adirondack not very tight indicating a younger tree. The adi seems to make a better tone, but it seems this wood doesn't have the strength of the old growth wood, and with medium gauge strings bridge will roll slightly towards the neck early on, causing the action to become higher. These are all OM style guitars with Martin style X bracing. Does anyone here agree or disagree with this?
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Old 08-28-2017, 09:46 AM
redir redir is offline
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You might want to consider getting into doing deflection testing. There are lots of studies that show that there really is not correlation between the tightness of annular rings and stiffness. I've handled enough tops by know to know this anecdotally. I tend to organize them in groups of stiffness and one of the stiffest pieces of top wood I have is a Carpathian top with very wide grain lines.

So my guess is that you probably built these guitars to a planned thickness? That would explain why tour red spruce tops are deforming. Build to a planned stiffness instead. If the top is floppy then it can be left thicker to get the desired stiffness.
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Old 08-28-2017, 10:45 AM
Rodger Knox Rodger Knox is offline
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Spruce is spruce, there's too much variation within each species to make any meaningful characterizations.
There is a relationship between density and stiffness that applies to all spruce.

The narrow growth rings indicate slow growth, and the wider rings indicate more rapid growth, they have nothing to do with the age of the tree. "Old Growth" spruce does generally have narrow grain lines because growing on the forest floor of a mature forest results in slow growth. Width of grain lines has no correlation to stiffness.
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Old 08-28-2017, 11:10 AM
martingitdave martingitdave is offline
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I can only answer from my perspective as a player, and with respect to Martin, Taylor, and Martin styled guitars, and more specifically, rosewood dreadnoughts.

The guitars I have owned with Stika tops, tonally, seemed to be more scooped in the mid range. They also had a high pitched shimmer to the overtones. Sitka seemed to "break up" when a heavy right hand is used. My Sitka guitars sound very sweet when finger picked at moderate volumes.

The guitars I have owned with red spruce "Adirondack" tops appear to have more mid range contribution, and don't, initially, have that same higher end shimmer. Also, the guitars with red spruce tops also have a higher volume and require more force before they "break up" in the high end. As the red spruce ages, it seems to gain more of the high end shimmer. This is also evident in two of my nearly identical guitars that are VTS and non VTS, respectively.

I've heard equal potential for bass response from both species. But, the red spruce topped guitars I have exude more volume in general. When measured with in dBA and dBC, red spruce and Sitka were within a 3 to 5 dB of each other. But, there was more pass punch from the red spruce topped guitars.

These are only my observations.
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Old 08-28-2017, 12:49 PM
Alan Carruth Alan Carruth is offline
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The longer I'm in this business, the less credit I give to any description of the tonal character of one or another species of wood. There is so much variation in measurable properties within species, and so much overlap between them, that talking about the properties of the different woods in anything other than a statistical way seems pointless. As far as the subjective aspects are concerned, that's another can of worms. We all tend to hear what we expect to hear, and it's difficult, once you have been told that a given top is Sitka spruce or whatever, the hear it in any other way. It would be really helpful to have some 'blind' test results to sort this out, but that's a major problem in itself. Having tried to do so, I can tell you that making guitars that sound alike, even from flitch-matched wood using careful controls, is difficult, and may well be impossible Given that the differences between two such instruments can be as great as the ones that are commonly ascribed to the differences in species, I can't give much weight to any of the 'magic wood' arguments. If we ever do understand these things well enough to make 'matched pairs' that sound alike on demand, then we'll be in a position to settle some of those questions relatively simply. Don't hold your breath. Otherwise we're stuck with statistical studies of large numbers of 'blind' tests, which nobody would bother to finance.
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Old 08-28-2017, 04:35 PM
printer2 printer2 is offline
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I have a size 5 guitar on the shelf (Poor thing feels abandoned, when will I get around to finishing it?) that has about three lines per inch. If it were true that the wider the grain the floppier it is this one should feel like balsa. It's stiffness is a little lower than the middle of the pack but not by much.
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Old 08-29-2017, 06:52 AM
redir redir is offline
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I've actually built two guitars side by side from wood that was cut right off the same log one after the other. I didn't do deflection testing back then nor did I even weigh the parts but I did thickness everything the same and built them as close as I could together. Sure enough I ended up with two different guitars. It's really amazing how it works like that but it does. It's what puts the 'magic' in this craft, something that has intrigued luthiers and musicians since the beginning of time.

Today we have many more luthiers taking the scientific approach but even still there is something that is not tangible in instrument building, in my humble opinion of course. As such you still have luthiers and musicians that seek out each other to make that perfect connection.

I'm think that body shape and size are the foremost consideration in the tone of the instrument over all. On a whim I started building a parlor guitar based on a late 1800's design, added my own bracing philosophy and a few other traits to it and out came a wonderful little guitar. I've built many of the same since then, each individual one sounds different relative to each other but they all have that characteristic C. Bruno Parlor copy guitar sound, regardless of what the top wood is or the backs and sides.

I know there are many luthiers who won't touch Sitka for anything other than bracing and I don't get that honestly. They are very well accomplished in their craft so it's not my place to even argue. They have their reasons and they are solid I'm sure. But I think I'm more in Alan's ball park in regards to the wood used in guitar making is so wide spread in it's physical properties that it's just not cut and dry in determining that sound you are after.

So how do we get the sound we are after? I don't know but I'll be chasing that for many more years to come.
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Old 08-29-2017, 07:21 AM
Dan of SC Dan of SC is offline
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I appreciate all the responses on this. Being a retired design/home builder, I equate guitar top wood with the floor system of a house. If I think about a piece of quarter sawn spruce, looking at the end grain, I see little dark vertical lines. These are the harder, stronger parts of the wood, and I equate these with floor joists. The closer together they are, the stiffer the floor or guitar top will be. To me it seems the reason spruce is the wood of choice for guitar tops is it's great strength to weight ratio. It is strong enough to resist the pull of the strings, but light enough to vibrate or resonate freely. Is this logical?
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Old 08-29-2017, 08:40 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by Dan of SC View Post
... I equate these with floor joists. The closer together they are, the stiffer the floor or guitar top will be. Is this logical?
It's logical, it just isn't true.

Ancient philosophers and physicists believed that heavier objects fall faster than lighter ones. It's logical, it just isn't true. It's easy to convince ourselves of all sorts of things that are not supported by real-world observation.
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Old 08-29-2017, 09:29 AM
redir redir is offline
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Dan SC I used to think the EXACT same thing as you. As Charles mentioned it simply is not true. You can test it yourself too. In fact I did once test brace wood. Just a few months ago I was building a parlor guitar and after taking the clamps off of one of the braces I realized I glued it on such that the vertical grain was horizontal... doh!

But I remembered reading somewhere that someone had done some testing that showed that the years old age old idea that vertical or quartersan bracing was the strongest was wrong. So I took some of the same brace stock and cut it in equal proportions and did a deflection test on it which indeed showed that the flat sawn braces were stiffer then the QS braces.

Out the window went 25 years of my own personal guitar making philosophy.

Of course there are still very good and valid reasons why one would still want to use QS for bracing. But still...
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Old 08-29-2017, 12:55 PM
Alan Carruth Alan Carruth is offline
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The floor joist analogy would be true enough if all of the joists were the same width, and otherwise equal in their properties. Usually they are not.

Wood that shows a 'normal' growth pattern tends to have hard latewood lines that are roughly proportional to the softer early wood. In a good year the width of the two sorts of lines varies together; if one is wider so it the other. Often the thing that dictates the ring spacing is the availability of moisture, but other things, such as sunlight and so on, have an impact.

In some circumstances wood will form latewood lines that are heavier in proportion. One of these is 'reaction wood'. In softwoods this forms on the down side of a tree that is leaning, or otherwise loaded in a way that might cause it to bend, such as on the side of a tree on a hillside, where there are more branches, or simply on the south side of a tree in the open. You also see reaction wood on the lower side of a branch, of course, and in the trunk below knots. Reaction wood grows with interlocked fibers that help to fight the tendency of the wood to 'cold creep' and droop. The latewood lines can be very thick, but because of the fact that the fibers are no longer well aligned with the axis of the tree the wood is not all that much stiffer along the grain. I have a pair of samples of old European spruce cut from the same beam a few inches apart, one showing strong reaction wood, and the other with more normal grain. They are both very dense, but the one with the reaction wood has a Young's modulus along the grain that is half that of the other piece. It's easy to hear the difference in the tap tone of the two bars.

Often you will see something similar in the grain of wood from near the base of a vary large tree. Although it lacks the strongly interlocked grain of true reaction wood, you will see the relatively heavy latewood lines. This is common in Douglas fir and redwood, and often shows up in many other types of softwood. Some folks call this 'compression grain'.

Trees can react very quickly to changes in loading and form compression or reaction wood for a few years when the situation warrants. This is one cause of 'racing stripes' in softwoods, I beleive.

In softwoods with 'normal' growth the Young's modulus along the grain tends to track density quite closely, with at least 60% of samples I've tested being within 10% of the same line. 'Reaction wood' or 'compression grain' tends to raise the density of the wood without a concomitant increase in Young's modulus. A top that shows compression grain will tend to be heavier when worked to a given stiffness. This works against 'responsiveness', but can help with 'headroom'. I have seen no particular correlation between Young's modulus either along or across the grain and ring spacing. Another report has it that there is a slight increase in crosswise E with tighter grain, up to a point (about 32 lines/inch, iirc). Whether that's important (if true) depends on what you think the role of crosswise stiffness is.
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  #12  
Old 08-29-2017, 03:13 PM
Frank Ford Frank Ford is offline
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Alan - THANKS FOR YOUR CONCISE, ENLIGHTENED RESPONSE!

It deserves repeating:


Quote:
Originally Posted by Alan Carruth View Post
The longer I'm in this business, the less credit I give to any description of the tonal character of one or another species of wood. There is so much variation in measurable properties within species, and so much overlap between them, that talking about the properties of the different woods in anything other than a statistical way seems pointless. As far as the subjective aspects are concerned, that's another can of worms. We all tend to hear what we expect to hear, and it's difficult, once you have been told that a given top is Sitka spruce or whatever, the hear it in any other way. It would be really helpful to have some 'blind' test results to sort this out, but that's a major problem in itself. Having tried to do so, I can tell you that making guitars that sound alike, even from flitch-matched wood using careful controls, is difficult, and may well be impossible Given that the differences between two such instruments can be as great as the ones that are commonly ascribed to the differences in species, I can't give much weight to any of the 'magic wood' arguments. If we ever do understand these things well enough to make 'matched pairs' that sound alike on demand, then we'll be in a position to settle some of those questions relatively simply. Don't hold your breath. Otherwise we're stuck with statistical studies of large numbers of 'blind' tests, which nobody would bother to finance.
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Old 08-29-2017, 03:25 PM
murrmac123 murrmac123 is offline
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Quote:
Originally Posted by charles Tauber View Post

Ancient philosophers and physicists believed that heavier objects fall faster than lighter ones. It's logical, it just isn't true. It's easy to convince ourselves of all sorts of things that are not supported by real-world observation.
Charles, try dropping a cannon ball and a feather out of a top story window and see which one hits the ground first ...





and please don't give a serious answer ...:-)
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  #14  
Old 08-29-2017, 06:04 PM
Dan of SC Dan of SC is offline
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You guys seem to know a lot more about this than me. Not surprising, but if all I see here is correct, why do folks make such a big deal about quartersawn?
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Old 08-29-2017, 06:55 PM
6L6 6L6 is offline
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Welp... I'm no expert on the various species of woods. However, I know what sound I like and it goes like this:

* Unplugged I like a dread with Adi top best.

* Plugged in I definitely prefer a Sitka top (all of my guitars sport a K&K Pure Mini pup).

Of my eight acoustics, only one has an Adi top (Collings D2HA).

I play mostly finger style and use a plastic thumbpic and two metal fingerpics. Otherwise I play with a Medium plastic flatpic.
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