Andy Powers Replies to my V-bracing Question

[Earl49]

Originally Posted by Herb Hunter

......I assume that by undertones, Andy is referring to a subharmonics.

Technically there is no such thing as sub-harmonics. That would be a lower fundamental, and the frequency you are interested in might be a harmonic of THAT. In the example of 110 Hz, the fundamental frequency would be 55 Hz and the first harmonic would be 110 Hz -- not the other way around. The harmonic might well be stronger in intensity than the fundamental. The relative amplitude of even and odd harmonics (harmonic series) is why a trumpet or a flute or a piano all playing a "C" note sound rather different.

My spidey sense always begins to tingle whenever someone says "sub-harmonic".

Originally Posted by Proclaimer888

With all the stuff written about this, what really matters to me is how it sounds.
No diagrams, equations or scientific evidence necessary.

^^ This is where the proverbial rubber meets the road. All else is irrelevant.

[Herb Hunter]

Originally Posted by frankmcr

Well, but that's what people almost always mean when they're talking about "intonation." All the posts on AGF re filing the nut or raising the bridge or changing string gauges or myriad other threads on improving the "intonation" of a guitar use the word in that sense.

The point is that V-bracing doesn’t address the intonation most people think of – the type that can be adjusted by modifying the nut, bridge or frets. It addresses the intonation of the soundboard and keep in mind that the listener mostly hears the soundboard.

[Rmz76]

It was nice of him to take the time to give you such a detailed response... Reading his comments I circle back to this idea of the guitar's inherent limitations (and imperfections) being a thing that gives it a distinct and beautiful tone. There is a camp of luthiers (Bob Taylor and Andy Powers included) that have been on a quest to make the guitar more piano like. I understand why for some players that would be a highly desired thing, but while it may get the instrument closer to perfection in a mathematical sense, I find a great deal of personality in those overtones and undertones that bring the pitch just a little off. There's something more organic to it and something very distinctive about it that says "I'm an acoustic guitar".

In the end we get back to the subjective nature of timbre/tonal character. Putting the math aside do these changes that lead closer to "perfection" enhance the tone of the instrument. If the overtones and undertones are being evened out/corrected I'd image it would take their timbre further away from what I'm looking for out of a guitar.

[v32 finish]

I'm really not sure what to make of this thread, but I'd offer my thanks to everyone who contributed.

I tend to agree with whoever mentioned 'where the rubber meets the road' -- until I've played the V braces myself, I can't offer much on the topic of their sound, but people who I trust have had very, very good things to say about them. That being said, I'm very hesitant to rush to conclusions, whether that be "this is just a marketing scheme, drink the Kool Aid, etc" -- OR, "this is revolutionary, redefining innovation, blabla".

As with most things, I think the truth lies somewhere in the middle. My opinion of Andy Powers doesn't matter, necessarily, but I get a weird vibe from him overall. That being said, I like him, and I believe him to be extremely passionate about what he does, and the guitars themselves speak their results.

Not to get lengthy or off topic, but.. I would be curious to learn more about acoustics in general and the properties of sound, I'm wondering if anyone has a good resource to point a beginner to, as all this is very interesting to me. I'm not necessarily technically inclined, but I'm no dunce either, and I'd like to understand better the physics of what makes our guitars so beautiful.


I also agree with whoever said that there's a certain 'character' to an acoustic guitar.. and trying to mathematically perfect every aspect of it may ultimately rob it of some of its charm (of course I'm paraphrasing). Anyway. Thanks again for a thoughtful read, and thanks for posting your response from Andy P. I'm headed to the Taylor show a week from Saturday (Fuller's Guitar, March 17th, Houston) and I'm hoping to A/B a couple V-brace vs. non... and maybe I'll be able to put that 614ce that's been haunting me on layaway


Cheers

[Monsoon1]

Originally Posted by Rmz76

It was nice of him to take the time to give you such a detailed response... Reading his comments I circle back to this idea of the guitar's inherent limitations (and imperfections) being a thing that gives it a distinct and beautiful tone. There is a camp of luthiers (Bob Taylor and Andy Powers included) that have been on a quest to make the guitar more piano like. I understand why for some players that would be a highly desired thing, but while it may get the instrument closer to perfection in a mathematical sense, I find a great deal of personality in those overtones and undertones that bring the pitch just a little off. There's something more organic to it and something very distinctive about it that says "I'm an acoustic guitar".

In the end we get back to the subjective nature of timbre/tonal character. Putting the math aside does these changes that lead closer to "perfection" enhance the tone of the instrument. If the overtones and undertones are being evened out/corrected I'd image it would take their timbre further away from what I'm looking for out of a guitar.

I've read many posts like this over the years here. And all reflecting that a great number of joyous sounds have been created over the years by guitars with loose tops running on the ragged edge, with bridges that rock back and forth like my grandma's rocking chair.
Will there come a time when this will be a thing of the past?

[Seagull S6]

Originally Posted by Picker2

I really appreciate Andy’s extensive response and I thank you for asking permission to post it here. But a lot of what Andy writes does not make sense. Such as “undertones” at half the fundamental frequency of a string. Never heard of or read about them.

If I find time I might elaborate on Andy’s story and pinpoint the flaws. On the other hand, I might as well not.

Just because you haven't heard about something does not mean it doesn't exist. I would say that Andy was asked a question and answered it with just plain old boring scientific fact. I don't see any "story" to try to shoot holes in.
https://en.wikipedia.org/wiki/Undertone_series

[Rmz76]

Originally Posted by Monsoon1

I've read many posts like this over the years here. And all reflecting that a great number of joyous sounds have been created over the years by guitars with loose tops running on the ragged edge, with bridges that rock back and forth like my grandma's rocking chair.
Will there come a time when this will be a thing of the past?

Entirely different thing. You're talking about problems beyond the design that the player could get fixed vs something that is distinctly part of the guitars tone and has been distinctly part of EVERY GREAT STEEL STRING ACOUSTIC GUITAR RECORDING throughout the decades of the recording industry (putting aside the occasional outlier like the ladder braced Harmony Page used on Stairway to Heaven).

To the group that is all in on getting the guitar as close to intonated perfection as possible (regardless if the end result takes us further from that signature acoustic sound), I would question just how much the new V-Class bracing gets us to the desired piano like result than X-bracing.

Taylor has only claimed that it gets the guitar closer to these targets Andy identified than Taylor's X-bracing before, but he has been careful not to talkin quantifiable terms and drop percentages, etc... No doubt these are measurements Taylor has taken and could release if they wanted to. Even if V-Class bracing got say 5% closer that would be all marketing would probably need to champion pushing this "Better intonation" idea.

Who knows? I think if he's going to take the discussion to a deeper technical level as he has and as he's going to be forced to in the coming months as players and builders are interested (I'm certain third-parties will listening careful to Andy's comments and taking measurements between the 2017 and 2018 models that apply). Looking forward to finally putting hands on one of these new Taylor models next week.

[Erithon]

Originally Posted by Seagull S6

Just because you haven't heard about something does not mean it doesn't exist. I would say that Andy was asked a question and answered it with just plain old boring scientific fact. I don't see any "story" to try to shoot holes in.
https://en.wikipedia.org/wiki/Undertone_series

Yes, the undertone series and subharmonics are real, but do they really apply to the acoustic guitar? (I have no idea - if someone knows, please jump in!) The very Wikipedia article you cite states that "The overtone series can be produced physically in two ways—either by overblowing a wind instrument, or by dividing a monochord string." The former is clearly irrelevant, and the latter seems to be too (unless someone has a guitar with a movable bridge). Now it may be that the information on Wikipedia is wrong or incomplete, and Andy certainly would be knowledgeable in this area so I'm willing to take his word (albeit with a grain of salt because: marketing); if Andy is correct, does anyone know how exactly the acoustic guitar produces undertones?

[Goodallboy]

Until I play about three dozen V-Braced Taylors, I'll have some idea if I like the concept.

Reading the opinions of those that haven't played about three dozen V-Braced Taylors, is a monumental waste of my time, if I think I'll learn anything from reading those opinions.

So keep a good attitude since most of what you're reading is for entertainment purposes only, and isn't meant to imply knowledge of the subject.

[Dwight]

Some of the references Andy was making are similar to harmonic and intermodulation distortion common in audio and radio frequency electronics.
He's going to need to demonstrate what he's talking about with spectrum analysis as to how that makes his design superior. I've never felt like I was being BSed when Bob Taylor presented a new idea like I do now.

He really should have stuck with "we made it different and we think it sounds better".

[Monsoon1]

Originally Posted by Rmz76

Entirely different thing. You're talking about problems beyond the design that the player could get fixed vs something that is distinctly part of the guitars tone and has been distinctly part of EVERY GREAT STEEL STRING ACOUSTIC GUITAR RECORDING throughout the decades of the recording industry (putting aside the occasional outlier like the ladder braced Harmony Page used on Stairway to Heaven).

To the group that is all in on getting the guitar as close to intonated perfection as possible (regardless if the end result takes us further from that signature acoustic sound), I would question just how much the new V-Class bracing gets us to the desired piano like result than X-bracing.

Taylor has only claimed that it gets the guitar closer to these targets Andy identified than Taylor's X-bracing before, but he has been careful not to talkin quantifiable terms and drop percentages, etc... No doubt these are measurements Taylor has taken and could release if they wanted to. Even if V-Class bracing got say 5% closer that would be all marketing would probably need to champion pushing this "Better intonation" idea.

Who knows? I think if he's going to take the discussion to a deeper technical level as he has and as he's going to be forced to in the coming months as players and builders are interested (I'm certain third-parties will listening careful to Andy's comments and taking measurements between the 2017 and 2018 models that apply). Looking forward to finally putting hands on one of these new Taylor models next week.

What on Earth are you carrying on about?
I have no problem with guitars as they have always existed.

[Rudy4]

Originally Posted by Picker2

I really appreciate Andy’s extensive response and I thank you for asking permission to post it here. But a lot of what Andy writes does not make sense. Such as “undertones” at half the fundamental frequency of a string. Never heard of or read about them.

If I find time I might elaborate on Andy’s story and pinpoint the flaws. On the other hand, I might as well not.

Oddly it makes perfect sense to me.

I've studied the complexities of sound produced by stringed instruments for a long time, and even though Andy Powers is using terminology that is sometimes more associated with layman's explanations the science is basically sound.

When you study the physics of sound it quickly becomes obvious that there's a lot more going on "under the hood" than what it appears from only having a cursory understanding of the complexities of sound produced from a stringed instrument.

When you start breaking down complex waveforms with techniques such as Fourier Analysis you begin to understand that each new harmonic of the primary tone has generated lower level frequencies that are sums and differences of each of the frequencies and harmonics, with those in turn generating even more partials and "sub-harmonics" of those frequencies generated as a result of the sums and differences of THOSE partials. It doesn't take long before all this gets way beyond the ability to grasp the mechanics easily. Then you have to figure out what the instrument itself is doing with those complex frequencies.

That's what Andy Powers is chasing, and his logic is firmly rooted in a good basic grasp on what may influence all this stuff happening behind the scenes. Make no mistake, this isn't something that it would be easy to tame the outcome of. I personally would suspect that a long history of experimentation by Andy Powers (and company) has resulted in a fortuitous, and possibly purely lucky, outcome.

Time, and feedback from a lot of players, will really tell if it's ultimately a "game-changer" or not. I'd be fairly skeptical, and I'm a huge Taylor fan.

I DO think it deserves a fair evaluation, and not the brush-off I've seen from some of the naysayers who might not give a fair chance to anything that may (or may not) improve the volume, tone, or robust design of the instrument that we all love so much.

[printer2]

I read the first part of his response and thought he is saying the right thing without getting too much in the technical side of resonating systems. I think he left out one bit that would have helped but no big deal. Where I started to be let down is when he got to this.

Moving now to the V class guitar designs. The unwanted motion of the guitar (or certain parts) is restricted. Most notably, the front to back rocking in line with the strings is reduced, much like an electric guitar. Once this aspect has been toned down to a more manageable level, the inherent resonant hot spots of a body which react in weird ways can be evened out. What is left is a body which has little preference as to which exact frequencies it vibrates at. Rather than trying to move in its chaotic type of motion, it relies more simply on the speed it is vibrating at. Think of it as the time of motion instead of the type of motion. Just like the cone of a loudspeaker. The effect of this we hear as richer overtone and harmonic content (since those are allowed to be amplified instead of muffled by the body) and notes which have audible pitch closer to the intended one.

On what their new system actually does.

Most notably, the front to back rocking in line with the strings is reduced, much like an electric guitar.

No idea why he mentions an electric guitar as they do not behave like an acoustic guitar, different animal. The rocking inline with the strings is a good piece of information which makes sense with the design of the bracing pattern. He is talking about the ling dipole.

Once this aspect has been toned down to a more manageable level, the inherent resonant hot spots of a body which react in weird ways can be evened out.

Just a 'I think this might work' statement, nothing wrong with it.

What is left is a body which has little preference as to which exact frequencies it vibrates at.

Which implies the resonant peaks are lower. A little guitar I made once. The peaks relate to the earlier diagram with the dipoles.

Rather than trying to move in its chaotic type of motion, it relies more simply on the speed it is vibrating at. Think of it as the time of motion instead of the type of motion.

????

Just like the cone of a loudspeaker.

Oh. Basically acting as a monopole. Like a lattice guitar. The center is more ridged and the edges are more compliant allowing the top to move. They have been doing this with their earlier guitars with their relief rout. Also they cordoned off the top of the guitar with the cross brace below the sound hole. More in lines with a classical guitar.

The effect of this we hear as richer overtone and harmonic content (since those are allowed to be amplified instead of muffled by the body) and notes which have audible pitch closer to the intended one.

50/50 on this one. Not sure how the notes are now not muffled as compared to before. The audible pitch closer, maybe.

[mattcran]

Originally Posted by printer2

I read the first part of his response and thought he is saying the right thing without getting too much in the technical side of resonating systems. I think he left out one bit that would have helped but no big deal. Where I started to be let down is when he got to this.



On what their new system actually does.



No idea why he mentions an electric guitar as they do not behave like an acoustic guitar, different animal. The rocking inline with the strings is a good piece of information which makes sense with the design of the bracing pattern. He is talking about the ling dipole.





Just a 'I think this might work' statement, nothing wrong with it.



Which implies the resonant peaks are lower. A little guitar I made once. The peaks relate to the earlier diagram with the dipoles.





????



Oh. Basically acting as a monopole. Like a lattice guitar. The center is more ridged and the edges are more compliant allowing the top to move. They have been doing this with their earlier guitars with their relief rout. Also they cordoned off the top of the guitar with the cross brace below the sound hole. More in lines with a classical guitar.





50/50 on this one. Not sure how the notes are now not muffled as compared to before. The audible pitch closer, maybe.

I was just going to say the exact same thing, but you beat me to it! Well done.

[endpin]

It would be interesting to me if someone with access to these things would check for "Wolf-Tones" and what frequencies (if any) they occur at.

Wolf-Tones are known to be a "Real-Thing" accepted by most everyone that plays or builds a stringed instrument.

My Taylor (a prototype with non-production bracing) has a marked "Wolf-Tone" at F# (on low E string)