MASTERGRADE: Have We Been Lied To? 

As a player (and one who buys too many guitars) I can say I am often swayed by the appearance of the guitar (master grade woods always work) but when playing, I always pick up the best sounding guitar first. Sadly, I have occasionally been "tricked" by the beauty of the wood at the point of purchase and I kick myself afterwards! Thanks, John Gig Harbor, WA

Excellent video. I been using the Gore / Gilet books that take you through the process and it is great to see you providing a well put together video with practical understanding. 'Pacific Rim Tonewoods' specialise in accurately grading tops from their billets. They have been working closely together with Trevor Gore to achieve these results. It is important that as luthiers to do these tests for better guitar builds that will perform better. WJ Guitars Australia

That's why I like to choose the tops myself. You can always find some gems in the AAA category that look great and also have good audible quality. Btw. for my doubletops I choose very light tops for the bottom/ inside layer since you can't see it anyways. Most times they are in the AA range. If I order tops bind I always go for Master so to be sure I get the looks at least. Thanks for the video. It really supported my feeling of the grading being mostly based on the visuals.

Did you ever listen to the tones of the Martin SuperD? Many say the Guat RW sounds awesome. So difficult to pull the trigger in it.

I had a wonderful guitar as a child made out of some kind of linoleum. It had a crank on the side and produced some wonderful tones. It only played one tune but it played with such presence. The tune was Yankee Doodle and I can still hear it now. "I'm a yankee doodle dandy, yankee doodle do or die". Magnificent.

Brilliant video as usual Tom 👍 No idea what grade the top for my recent guitar is! I asked them to pick the best sounding one, and I'm pretty sure they delivered. That's all I care about (although I'm happy with how the top looks too)

" My beautiful assistant here." It's lucky you are not a magician! ;-)

Really enjoyed this video, especially with the blindfold exercise.

Outstanding!!! Thank you so much. Fabulously entertaining and educational.

Now, how about a comparison of Sitka Spruce, Adirondack Spruce, Koa, Mohagany and Spele.

Awesome, fantastic video in the way you show those characteristics in a logical, easy to understand way. Giuliano's book does the same. I'm a certified, clinical wood tone nerd and really enjoyed this comparison. I did a similar "drop tone" comparison with bone saddles (without the FFT- using 8 same-sized bones and two Tusq saddles ), arranging them in ascending order of pitch. The differences were amazing, and eye opening with all of them demonstrating a different pitch, probably based on the aggregate density of each piece. The pitch was not well correlated with the weight (mass) of the bone either. Thanks for an excellent video...

09/13/2023: I am retired and just a beginner using my guitar, and so far it sounds OK to me. But, I am no expert at all. I have a 2022 Guild D-150CE Westerly Collection Dreadnaught with cut away. It is built with all solid woods: Spruce top, and Rosewood sides and back, and Rosewood fingerboard. Could you tell me what grade this model guitar has? It sounds warm and loud to me with Elixir 10-47 light NANOWEB strings (I would use lighter strings, if it would help my fingers). Also, you may thik this is crazy, but I boiught a stick-on rubberish bck pad z9doe not hurt the finish), and it gave the guitar a little warmer soud, and no buckle scratches at all. So, what do you think of the grade of Spruce top and using the pad? May I ask a second question. I bought a Taylor high end (about $3,000) rosewood sides and back with Spruse top. The grain had these horrible scatch mark designs in the grain. Taylor representative said that is called Bear Claw design in grain. I hated it and sent it back to by the Guild with really straight grain. What do you think of the Bear Claw grain? Also, the "V" bracing Tayor uses also seems questionable to me. I will stay with "X" or Ladder Bracing.

I have one factory guitar that costs $159 with a solid spruce top that has wide, wonky, varied grain with darker and lighter streaks. Then I have another solid spruce top factory guitar that is worth four times as much. It has a tighter, straighter grain and lovely silking all over. Guess what? I like the wonky spruce better. It just SOUNDS better, sings more clearly, sweeter, sustains longer, etc. Luckily the more expensive guitar was sent to me by accident by Amazon, so it's not only pretty to look at, but also free.

And there you have it..... that should tell you all you need to know about his skills in identifying wood by its feel and tonal properties....... as well as the "premium" materials and prices...... its all a sham

Greeeeeeat video! (I'm a mech eng 😁). Do you have some other books to suggest?! Both building theory and practice or whatever on guitar luthiery! Would be really appreciated!

Great video. I think the answer to the question of whether mastergrade is worth it is quite simply another question: 'what for?' If you are after a look, you have no choice but to go with the best looking one, or close to it. With regard to sound. I had the same results as you, but I don't believe this is that significant. You are working with boards a more or less uniform overthickness. I guess I just want them to sound vaguely musical, rather than clunky, at this stage. I try and thickness a board till it has a sound I like but isn't floppy like cardboard 😅. However, beyond that, I'm not convinced there's much to be gained from free tapping. After all, you're going to be bracing that top. Why not wait till you have some braces on, then start tapping and refining. Gone to far in thicknessing and got a floppier piece of wood? Won't tougher bracing sort that out? Once you got into the maths, I was fascinated. You managed to put a whole load of information into a meaningful format in a short spell of time. Completely brilliant. Have to get that book now, even if I never do the measurements. Thanks a lot.

Yet we all want to buy that extreme rare 5000 year old woods 😂😂😂

It is interesting... I think we maybe get too hung up on this - especially visual. A Good friend, the classical maker David Whiteman has repaired and restored instruments by Torres and the like, and in many cases the wood used would not be classified as anything other that A by today's approach... Torres would have used what wa available and used his skill in understanding how to build with that wood - getting the most from it... and his results were not bad ;-)

I wish we could share some knowledge some day, some video. I’ve been nerdy about tone woods for 30 years and it’s rare to find a fellow nerd. Can we talk about torrefied tops? I know the real deal story about how we approach tops, bracing, and historic features. It’s no secret!

I have a larrivee C-05 with probably (aestetically at least) an AA grade sitka top and it sounds incredible. The fundamentals are distinct and punchy and the sustain is crazy for a guitar with mahogany back and sides. I have seen others like it. Unless you're really using crap wood, any reasonably well quarter sawn, book matched, sitka top would likely be consistent enough, physical properties wise if not aestetically, across all of those grades to make a good sounding guitar so long as the guitars are designed well enough otherwise.

I wish we could share some knowledge some day, some video. I’ve been nerdy about tone woods for 30 years and it’s rare to find a fellow nerd. Let’s tawk…

That tapping has nothing to do from the end result.. its like HiFi people taling about their speakers with a acoustically shit room. You need to understand how sound works. And that takes decades to learn. These videos useless. I understand that you have done this for alot of time. But sound has rules. And when you understand it. Some use vibrations with the sand/salt shit. In there acoustically shit basement. And dosent understand that the environment is gonna to change the result. No matter what their grade of wood they are using. Sorry for the language. But to do sound, you need to understand sound.

Great Video Tom. Going to buy this book on your recommendation. Do you believe this rank-order would hold true when the tops are brought down to final shape and thickness?

As wood is dynamic and ultimately requires "fixing" after time, why not use a different material with the same or better acoustic properties to construct a guitar? Perhaps a guitar which would not bend out of shape?

Your shop has ambiance of my living room. Nice “set”.

I read once that almost no wood suppliers are tone tapping as part of their grading process. It’s all aesthetics.

Great video. Thank you for your honest approach.

You can't judge a book by it's cover. Neither a guitar it seems.

Curious if the sound difference was more due to the dryness of the wood as some of the boards could have aged far more than others. Including a torrefied board would have been interesting.

*dimensionally stable and moves proportionally with changing temperature and humidity environments* - it is NOT about the tone!!! But, for example, about stable intonation in different environments. You can blindly test and find that A-grade sounds better than AAAA; but you also need to test its' intonation/stability/tone in different environments, and so on... Here is StewMac grading, explicitly mentioning that it is mostly *not about tone* but instead *about appearance*; you can find it at "Western Red Cedar Soundboard" page for example. If appearance is bad, but tone is exceptional.... it will never be AAAA graded by luthiers, and it seems it is common knowledge... Quote: Color: Higher grade soundboards have more consistent color (****color affects the instrument's appearance only, not its tone****). Grain straightness: Higher soundboard grades have straighter, tighter, and more uniform grain. While closely spaced grain has been traditionally favored, luthiers have found that wider grain can produce very good tone. Quartersawn grain: The higher the grade, the more closely quartersawn the wood. Perfectly quartered wood is more dimensionally stable and moves proportionally with changing temperature and humidity environments. This helps to ensure structural integrity and resists cracking better than other types of cuts. Grain run-out: Our soundboards are sawn from split billets to reduce the amount of grain "run-out," caused by a twist in the tree. By splitting the log, the twist is followed when sawing. Higher grade soundboards have less run-out. Origin and drying: Our soundboards (unless otherwise noted) are from western North America, and have been kiln-dried and stored in a climate controlled environment.

All this is great. I personally perform some tests like these too, but the incredible (at least for me) is that in the end, after having the guitar strung and the wood well settled (after about 2-3 months of daily use), I could figure out that sometimes the “worst wood” makes the better sounding instrument, and vice-versa. At least in the short-term time. So, there must be something else to discover. I keep learning. Thanks for the information.

The grading has always been subjective and relative. AAA beats AA which beats A. The best looking, again LOOKING, of the AAA are sold as "master grade." No stiffness testing is done. Runout is up to the sawyer to determine, though under finish, runout is obvious--one side of the bookmatch shows darker than the other. One of the criteria for grading was always lines per inch, which is not not necessarily indicative of quality. Too slow growth is probably detrimental to spruce stiffness. It might be good for WRC, which yields guitar tops (and shingles!) from trees many hundreds of years old. In my experience, species come first and then climate. European spruce varies a lot by location. Douglas Fir, not often used for instruments, varies so much by climate that Coastal DF has historically been a different lumber grade than Interior. Modulus of Elasticity numbers in the literature are averages. Stiffness and density can vary from one side of a log to the other, and can vary greatly according to height in the tree. Overall stiffness is easy to measure by tap tone. All dimensions being equal the one with giving the higher note has the higher stiffness to weight ratio. Watch the thickness though. Stiffness of any beam varies to the third power of its thickness (and inversely to the third power of its length).

Your tap test was actually accurate! Your conclusion at the end is wrong about which one has the highest specific modulus. Specific modulus is the technical term for "stiffness to density." Assuming you calculated modulus correctly and measured accurately, the actual order for these is as follows, with their specific modulus in MPa*m^3/kg, by dividing elastic modulus by density: 1. AA - 27.7 2. A - 27.6 (certainly within the error range of this test of AA) 3. Master - 24.1 4. AAA - 23.5 5. Master+ - 23.2 What this means is that your tap test was actually just as accurate as measuring everything scientifically! I bet you have a great ear at this point. I also love tap testing wood. While your order for AA an A was reversed, they are so close that it's well within the error range. A specific modulus of 27.7 is actually crazy. I have a running list of data that I've been compiling from The Wood Database, and a specific modulus of 27.7 is higher than any wood on the chart. This is why I do not want to order tonewood online as I continue getting into lutherie. I'd rather be personally present to tap boards so I can listen myself. As I keep getting into it, I keep getting the sense that I'm running into a lot of voodoo and marketing about wood grades, and that the grading of wood is really not going to be particularly reliable. If there were actually rigorous testing of boards where you measure specific modulus and Q factor, that would be a far greater determining factor for guitar woods, rather than this voodoo type of thing we have going on now with grain density being a factor. I've seen denser grains fail people's blind intuition before - Daisy Tempest did a blind tap test, and the so-called high value moon spruce was inferior to different tonewood. Technically speaking, specific modulus is only going to correlate to volume. The other thing you can't really account for in this test is that wood is anisotropic, which means that its properties are not the same in every direction or evenly distributed. Funny story, I actually built a lyre recently as my first instrument. The wood is literally cedar from the hardware store, which I found by tapping a huge amount of boards until I found the ones that seemed to ring the longest and clearest for their shape, with the most harmonics for their shape. This is really the way. By the way, you can also estimate Q by using a microphone and looking at the waveform amplitude diminishing. If you think about it, Q is a measure of how much energy is lost after each oscillation, and it follows an exponential decay pattern. If you had the same dimensions, to rank wood by Q factor, you can simply compare the timestamp of the tap to the timestamp that the tone is no longer picked up by the microphone. This might sound like it would be hard to see what's going on, but really you can see it very clearly if you just do it in a DAW - the higher sustain woods will very clearly have a longer envelope, so it's actually not too hard to eyeball it. I bet this is probably why douglas fir isn't used as much - it probably has a high Q factor compared to spruce, despite being very stiff, so it just doesn't sound as "nice." Woods that lack sustain probably make good guitars if your aim is to make a punchy, articulate instrument. What you should do next as a video is actually measure these characteristics for a bunch of the wood in your shop, and then make a guitar out of the woods that have the highest Q factors and specific modulus. What I also suspect though is that Q factor is going to impact the tone of the guitar the most. If you have high Q wood, it's going to absorb more energy into the wood rather than into the air, making your guitar have less sustain. Q factor shouldn't necessarily have a correlation to specific modulus, but maybe it does, I don't know, you should actually test this. It might actually correlate, but you'd need a lot of data points. I think I'd prioritize wood that has a very low Q factor compared wood that is absolutely highest on stiffness to weight.

It could be you're poor at grading tops? :) Kiddin'

I never believe in it.

I think I know the supplier...what a great wood he have!

I think for the most part grading is based on visuals with good tap tones

Times the acceleration due to gravity?

I have owned many guitars, down to 6. 15 of my guitars were Martins gong all the way back to a 1939 00-17, my first guitar. bought in 1961 for $4.. yes, four dollars. I was ripped off, no case. Among my current guitars is a 2015 a Martin 00-18V with a cosmetic #8 top up to 20 lines per inch and lots of silk. (Martin's highest grading) . Highly flamed mahogany backs and sides, genuine mahogany v neck no wings one piece. I also own a (one of 370 made) 0000-1 Martin from 1997, this is my second... sold the first in a fit of poverty. It has a grade 3-4 top with 5 lines to the inch up to 8 and then down to 4 lines per inch. . No runout. It has laminated backs and sides and absolutely top quality genuine mahogany backs and neck. I very much enjoy the 00-18v as I am partial to 00s. The 0000-1 has more base and is the "universal" guitar. The 00 has a value of $2800 and the 0000-1 has a cash value of $700-$900. I consider them equals in the joy of playing them. Proof that a cheap apple crate top is not a deterrent to tone, playability or purchase. Get over the cosmetics and obscene pricing, .. its a scam. One of the worst Martins I bought (new) was a D-18 GE.. what a dog .. bought it because I thought it would come around, never did, that in spite of its "perfect" numero uno Adirondack top.

Great video. Unfortunately I couldn't find the link to the software you used in the video. Could you please share the link or name? Thanks!

This is SUCH a cool video seems like from this that flexibility is also actually a good thing! Which makes sense right? The wood needs to flex with the sound waves or it would dampen or muddy up the sound. As well as needing to be thin and somewhat rigid. The more lines the slower growing the tree the tighter the grain the denser the wood that if very straight would flex really well in one direction. Allowing all the desirable attributes of tone woods to coexist maximally! Thats so freaking cool!!! Thats why the visuals of the tone wood actually are important to the quality because in that way it actually does directly if minimally affects the sound. Im blown away! Thank u for this vid!!

Very interesting... though I think as a builder, one would be able to "work" with the properties of any wood to achieve the desired result. For example, the A grade board is the heaviest, but also can be theoretically worked the thinnest of the five since it's also the stiffest, while another board may be lighter, it's a little less stiff and thus needs to be kept a little thicker, which negates some of the benefits of its lightness. So I wonder what would be the effect if this test were run again, with each board taken to the thickness that produces your target stiffness by deflection, to see how that effects sound transmission...

A lot of snake oil salesmen in the guitar world…

You use mathematics, but not statistics, to draw conclusions from subjective and objective tests. If you had done the same experiment on at least 40 games of each type of grade, then you would have a better idea of ​​which is better and that is just barely touching the line of statistically valid. Still, I really liked your video.

Fascinating video. Thanks for sharing

It s soooooo simple… “low grade” wood is by definition already “broken” and will sound 10x better than master grade. However, 50 years from now, master grade will sound better.

Thanks Tom your ability to provide such wonderful experiments... feels like being back in physics class, I really enjoy your creativity with your presentations!!! it would be interesting to execute this test 5 times or a number greater 1... keep up the Great Work!!!

Now, isn’t all that fascinating! Don’t judge a book by its cover, springs to mind; having said that, you do look at a guitar when you’re not playing it and visual inspiration is all part of the joy of guitar ownership. Did you say the boards all scored 13? Perhaps Douglas Adams got his sums wrong…hit the Level 42 soundtrack button, Ted! (You may have some explaining to do to your padawan, Tom…)

Great Video Tom, I’ve just started watching your channel and I’m blown away, great content. What other books would you recommend? Thanks 🙏

5 yrs ago I built a 17” jumbo for myself. It has the best Sitka , or any other type wood top I have ever seen. Incredibly tight, perfectly straight, perfectly quartered , medullary rays across the whole top, perfect colour. Since then I have gone to torrefied tops almost exclusively on my steel strings. Wider grain, but straight. Consistently better sounding guitars. I’m sold!!

Great video Tommy. Thanks for sharing buddy.

Thanks for the excellent detailed analysis and tests you've carried out. The results were quite interesting. There are also interesting comparisons of wood grain used on some famous Stradivarius Violins, some of which have maybe "A Grade" looking wood. Knowing how to get the best results from the wood you've got is where the Art lives, and a great Maker can get outstanding results from a wood that looks quite mediocre.

Ive built a guitar with two knots in the top just because that piece was extraordinary when tapped. Only cost me 10 euro because of the visual flaws but ended up being one of my best sounding builds. I love that most companys grade by look because it means i get to pick some not so good looking but great sounding soundboards that i would class mastergrade for sound from the a or aa pile.

Thought-provoking indeed! Nice work, Tom!! Thank you, kindly!!

Wow, how interesting. Made me smile. Thanks.

I'm curious to know how much the bracing can tune out the variances in the performance. For example, can a low score on a blank board be improved with careful bracing shaping.

Starting my build of my first instrument this week, a trapezoidal violin. This video reinforces my decision to go to the local Aircraft Spruce and pick out some A grade Sitka

... young master Smith, there will be a test on relative density at the end of this lesson, not however on Girls netball which you seem much keener on studying out of the window .....

Does the tape stuck on the boards not alter the frequency of the monopole measurement?

Wonderful video! It reinforces for me the need for luthiers and musicians to develop their hearing. I have on order a custom made guitar from luthier Ben Wilborn -- his videos & yours always amaze me of the subtleties each of you hear, e.g. to notice the sonic differences of a guitar made with the same species. It's like me learning to play a guitar and muscle memories in my fingers develop as I play more. I think we all need to develop sonic memories to appreciate hearing the differences in tapping tonewoods and finished instruments. These videos help me know what to listen for. Thank you.

I bought a guitar with “AA grade” top wood and a few builders looked at the guitar and said it looks like like a really good piece of spruce. It was still very straight right grained, but lacked the medullary rays. And every guitarist loves the tone. Goes to show that sometimes you can still find a gem within those budget tops

I'm not that surprised by the result.

I have two dreadnoughts built in the 1970s. One is American with solid Mahogany back and sides, and going by the visuals probably a double A top. The other is Japanese with laminated rosewood back and sides, and at least a master grade top and likely plus. There are a lot of different factors, and they both sound excellent, but I prefer the sound of the American one.

Really insightful! Answered some questions I’ve always had.

I have already read the book and been making measurements and I found the video very entertaining. The blindfold test was great! I have to say I find very important the measurments along the way especially when the top is attached to the rims cause there is when you can fine-tune the tops to your liking.

Most interesting to me are little bits of info I come across on the internet like John Greven saying he can, when tapping the raw plates, hear the qualities of the in the raw top in the finished guitar (I think he’s built about 2000 guitars by hand now). Or Bruce Sexauer building two identical guitars, one with adi and one with englemann, passing them around a luthiers meeting and having them guess which was adi and which was englemann, and the luthiers all thinking the englemann was the adi.

Good video! I learned something today 👍

Two bottom lines; first the measurable sonic performance of the differently graded tops should be swamped by build quality and design, and second, for builders it would make sense to pair the beautiful and expensive woods and add in the best embellishments for the buyers who value and can pay for looks while saving more plain but perfectly serviceable woods for serious musicians who would benefit from but have difficulty paying for a hand built guitar. Given that I don't need to make a living at this, I will focus on the less expensive good players.

Very informative video. A great reminder to all that when it comes to the magic of tone wood, we really can't reduce it down to a single or a small group of metrics... There's lots of room for audial vs aesthetics vs craftsmanship judgements needed to build quality instruments.

This is actualy an extraordinary video! Could you please share your thouthts regarding aukume wood? Sorry if my language is not correct

The placebo effect is REAL!!!!

WOW a Luthier on RU-vid that actually knows what he is talking about. Yes it is understandable Math and Science.

Oh man the Maths!!!!!!!

Great demo. I would be inclined to buy 3 or 4 sets of single A tops, select the best 2 sets, and return or sell the rest.

How do you find out if a soundboard has runout?

Brilliant

This is amazing! Great job man

Science, baby x

Great video Tom. It's heartening to see that tone isn't all hit and hope where getting a good one isn't just a matter of luck. Would be interesting to know how much maths was applied by Martin in the 30's. And also exciting to wonder how this approach will convert to tonal maturity as these guitars age.

This was super interesting. It really seems that we humans tend to hear with our eyes,at least in part.

Brilliant video.

What a honest Luthier!

Appreciate the great video but this is not science. Science is a method of establishing cause and effect of a natural phenomena starting with a hypothesis then experimentation with independent and dependent variables. This video is measuring, testing and maths but that's not actual science. Cheers