Body wood affects tone

Three-ColourSunburst

OK, I have found some real academic research on this topic, overseen by a Professor of physics and acoustics. I have also found a TV clip about their research, a full text copy of their paper and also some discussion by the leading author of other research they have done into this topic, including some blind listening tests. This will do for now. It's in Portuguese, probably because any English speaking academic putting a research proposal forward to study such a topic would risk becoming the next Eric Braithwaite! Looks pretty rigorous, using a mechanical picking device to avoid the problem of human players 'unconsciously' altering their picking technique in order to get the tone they expect.

Sobre o acoplamento corda-corpo em guitarras elétricas e sua relação com o timbre do instrumento. Physicæ 9, 2010, pp. 24 - 29

'String-body coupling on electric guitars and its relation with the timbre of the instrument.'

Rodrigo Mateus Pereira(1), Albary Laibida Junior, Thiago Corrêa de Freitas.

(1) Tecnologia em Luteria, Universidade Federal do Paraná, Brazil.

Abstract.

Nine electric guitar bodies were built in the form of the Telecaster model by the author RMP. These were assembled using the same neck and pickup assembly. Once each body was assembled two strings of the electric guitar were mechanically excited and the sound, obtained directly from the instrument, was recorded for later analysis. Also recorded was a musical piece played with each electric guitar. These sounds were analysed via a Fourier transform in order to obtain the component harmonics of the sound, these harmonics are responsible for the timbre of the instrument. The harmonic spectra of each electric guitar were compared to each other and there were no significant differences between them. Thus the variations of timbre of electric guitars, according to the results obtained here, depend on other factors than the wood of the body itself, a fact that arises from the absence of a significant coupling between the string and the body of the instrument. Also proposed is a modelling of the string-body coupling, which shows that only a negligible amount of energy from the vibrating string reaches the body of the instrument and that a smaller amount still returns up the string.

http://physicae.ifi.unicamp.br/index.php/physicae/article/view/physicae.9.5/116    

Three-ColourSunburst

The blind sound testing using the guitars in those clips, with professional guitarists and luthiers as subjects also sounds as though it was interesting. Basically, they all claimed they could hear distinct differences in timbre as the sound clips of the guitars were rotated. However, there was no consistency in their individual choices,each person made a different set of choices, and they still argued that they could hear distinct tonal differences even when they were presented with the same guitar more than once!

I have also found some forum comments by the primary author where he discusses his methods and research in detail. I haven't yet found any respondents telling him to flush his research "down the toilet where bullshit belongs". Perhaps disappointingly, non of his research seems to have involved 'tapping and sniffing' any bits of wood.

Seems that there is solid academic research into this topic out there, just not in English.

Conclusion? The effects of 'tone wood' are all in the mind and are not supported by the laws of physics. Yes, different guitars may 'feel' different in the hands, may even sound different acoustically and the raw wood might smell differently if you sniff it. However, due to the fact that the string-body coupling is weak, this will not be translated into a different amplified sound, as heard by a properly made, non-microphonic electromagnetic pickup. The rest is just cork sniffing.(Or should that be wood sniffing!)

Unless anyone has any credible evidence to the contrary, of course.

Sassafras

Conclusive proof! One indisputable 'scientific' experiment.
I must get my hearing tested, I hadn't realised I was so cloth-eared.
Either that or I must get one of those machines to do my listening for me.

Three-ColourSunburst

Sassafras said:

Conclusive proof! One indisputable 'scientific' experiment.
I must get my hearing tested, I hadn't realised I was so cloth-eared.
Either that or I must get one of those machines to do my listening for me.

Don't tell me. You only use Pear Anjou speaker cables on your hi-fi, you can really hear the difference. A snip at only $7,250 a pair. 

Rabs

Its one of the greatest and worst things about working with wood...

EVERY piece is slightly different...  So every guitar is slightly different. They all sound like electric guitars within a certain frequency range (which is determined by the pickups) but the exact frequency response will depend on the density of the wood which varies throughout a single piece. Anyone who has worked with wood will tell you that.. As you cut through it you get harder areas.

The most convincing test for this I ever saw (I will see if I can find it again) was a guy who took a pickup and attached it to a block of wood and had a direct output to an amp.. Then he placed a small music box at the opposite end of the wood (one of those old time ones where you have to turn the handle and it revolves a barrel around which pings some metal strips) and as he turned the handle you could hear the vibrations being picked up through the wood.

So if this is the case that the pickups DO pickup vibration from the wood  (and I do think they do) as well as the strings the it makes perfect sense that if each piece of wood is different each one will react slightly differently...

Im not calling this scientific proof before anyone jumps down my throat..

Three-ColourSunburst

Rabs said:

The most convincing test for this I ever saw (I will see if I can find it again) was a guy who took a pickup and attached it to a block of wood and had a direct output to an amp.. Then he placed a small music box at the opposite end of the wood (one of those old time ones where you have to turn the handle and it revolves a barrel around which pings some metal strips) and as he turned the handle you could hear the vibrations being picked up through the wood.

Debunked in this video. (Get past the intro, he actually talks a lot of sense in this.)

So if this is the case that the pickups DO pickup vibration from the wood  (and I do think they do) as well as the strings the it makes perfect sense that if each piece of wood is different each one will react slightly differently...

Debunked by Rodrigo Mateus Pereira, Albary Laibida Junior, Thiago Corrêa de Freitas in ''String-body coupling on electric guitars and its relation with the timbre of the instrument.' Physicæ 9, 2010, pp. 24 - 29

Rabs

Well their debunking is just as dodgy as any of the so called tests to prove it.. He may seem like hes talking sense but that doesn't make it so.

This is the issue.  Theres no real proof either way...  So i say think what ever makes you happy.. If knowing you have a classic combination of tried and tested "tonewoods" makes you happy then cool..  If you think they are all the same and it doesnt matter then cool...

I also think that if people maybe paid more attention to how they play than what they play we would all be a lot happier (and im not being patronising saying im a great player or anything cos im really not).. 

NelsonP

In the original vid all of the planks of wood sound pretty decent considering that's what they are. Makes me wonder what you pay for in high end guitars!

Disappearing into the theory rabbit hole for a moment...

I think that Paul Reed Smith makes a very good point  in that an ideal instrument has the least amount of 'subtraction' from the original energy in the strings.

But it's also more complicated than that.

Resonance requires no more energy in (and therefore does not rob your strings of energy). Its simply that all of the energy is going on the right direction to increase the amplitude of the oscillation at that particular frequency. Think of when you sing in the shower. Some notes are louder than others yet you don't have to sing any louder to produce them. Or when you push a kid on a swing. If the input frequency is right then you get resonance and a bigger amplitude for the same energy in. The same is true with your strings and guitar.

But with an electric guitar it is complicated by the fact that you have three (or more?) major components in the system i.e. Strings, guitar and amp/speaker. So you can have resonance between all of them. That's quite a complicated system.

For any frequency that resonates you'll also get some harmonics that resonate with it. When you find a resonant frequency singing in  the shower you'll also get a bit of resonance if you sing an octave higher or lower.

So perhaps guitars that resonate more at the RIGHT frequencies also actually sound better?

The wood probably plays a role here. The material that the guitar is made from probably matters to the extent that it provides a good basis for these resonant frequencies.  This is what I think you can hear in the clip, especially maple vs mahogany.

I suspect there is a lot to learn in this which can either be learned by trial and error or by the application of physics. Art AND science. McCarty, Fender, Reed Smith, Jackson etc have probably all learned this one way or another.

Of course this could all be wrong, but just my two pence....

MartinB

I haven't fully translated that Brazilian paper (I've been out playing a gig, I recommend doing that), but it seems like an interesting bit of testing.  The paper is useful in suggesting that the choice of body wood is not the most useful thing to adjust for overall brighter/darker type timbral content.  Let's not extrapolate too far from the results they actually present though. 
The graphs look like they're measuring harmonic content in a time averaged way, to look at overall differences in timbre between the bodies.  It doesn't look like they've examined time-related behaviour, unless that's buried in the text somewhere.  Since one of the more common claims about body wood choice is that it affects the envelope of the note, this would be a fruitful area for further work.  They're looking at bolt-on neck tele bodies, and it seems not inconceivable that different neck/body geometry, types of neck joint and bridge might behave differently in terms of string to body coupling.  It also seems likely that the neck may have some effect, which is not examined here. 
So, it's interesting reading, I appreciate it being posted here, but what I don't take from it is "That's it for tonewood then". 

GoldenEraGuitars

Sporky said:

I think there's also some confusion in that different people mean different things by "sound the same".

They all sound like electric guitars. None of them sound like bassoons or snare drums or waterfalls. Different bits of wood may well sound different, but it's last 2% stuff, not first 98%.

The thread had no need to continue after this.

Well said.

Three-ColourSunburst

NelsonP said:

...I think that Paul Reed Smith makes a very good point  in that an ideal instrument has the least amount of 'subtraction' from the original energy in the strings.

...with an electric guitar it is complicated by the fact that you have three (or more?) major components in the system i.e. Strings, guitar and amp/speaker. So you can have resonance between all of them. That's quite a complicated system.

...perhaps guitars that resonate more at the RIGHT frequencies also actually sound better?

These points have already been discussed. Yes, different systems may well have a different degree of damping, but this will just affect the overall level of energy maintained in the system, and so the sustain. The upper hamonics on a stiff steel string always decay the most rapidly in any case, which is an inescapable property of the string itself, so it is not as if the body material could change this, thereby altering the harmonic balance.

As to resonance. For resonance to selectively preserve or enhance certain harmonic frequencies in a way that consistently affects the timbre of the sound, it would have to resonate in a way that affects all frequencies / notes in the same way. However, the body and neck of an electric guitar resonate at specific frequencies, which might not even correspond to any single tuned note, let alone the whole chromatic scale.

Where resonance does show an effect, this is usually in the way it creates undesirable 'wolf tones' (if one keeps adding energy to the system, as with a bowed instrument) or 'dead spots'. Here is a paper on this topic.

https://www.unibw.de/lrt4/mechanik/mitarbeiter/ehem-mitarbeiter/hfleischer/deadspots-en

https://www.researchgate.net/profile/Helmut_Fleischer/publication/282789912_Fleischer_H_und_Zwicker_T_Investigating_dead_spots_of_electric_guitars_Acustica_united_with_acta_acustica_85_1999_128_-135/links/561c9f8208ae6d17308b2365/Fleischer-H-und-Zwicker-T-Investigating-dead-spots-of-electric-guitars-Acustica-united-with-acta-acustica-85-1999-128-135.pdf

Sporky

Three-ColourSunburst said:

For resonance to selectively preserve or enhance certain harmonic frequencies in a way that consistently affects the timbre of the sound, it would have to resonate in a way that affects all frequencies / notes in the same way.

An object cannot resonate at all frequencies equally - that's not resonance. Look up formants.

C-, must think more clearly.

Three-ColourSunburst

lonestar said:

Sporky said:

They all sound like electric guitars. None of them sound like bassoons or snare drums or waterfalls. Different bits of wood may well sound different, but it's last 2% stuff, not first 98%.

The thread had no need to continue after this.

Well said.

But it is that supposed '2%' that those who believe in the myth of solid body electric guitar 'tone wood' think is so important. (And given the foregoing research findings, I think calling it a myth is now fair comment.) Thing is, to make a reliably recognisable difference it would very probably have to make a lot more than 2% difference - and in a way that consistently affects the timbre - and it actually makes a lot less difference than that. Most likely absolutely no difference at all, or next to no difference and, going by the available research, certainly less than is perceptible.

Still, doubtless the 'wood sniffers' will continue to allow their preconceptions about the way things 'should' sound to dominate what they 'hear', perhaps reinforced by subtle, unconscious changes in the way they play to get the sound they expect, and will maintain that they can hear a difference, just as some people  will continue to maintain that they can hear the difference between a $50 speaker cable and one costing $7250.

Unless anyone can point to research showing otherwise, of course.

kin

 When you've finished with this topic could you start a thread on the difference in tone depending on what wood is used in the construction of a speaker cabinet or the density of the grill cloth used?

   

Megii

So - I've been thinking about this, and specifically the implications, just supposing @Three-ColourSunburst is correct... If I understand right, it would mean, for example, that:

I could take a treasured 1962 strat ("amazing responsive instrument, fabulous tone, just sings" etc.) and replace the body with anything of the same dimensions (a cheap copy off ebay? plywood?) and the guitar would sound just the same. Also, as a side note: issues about thick poly finishes vanish, since this is just part of a guitar body that can have no influence anyhow.

And then I think, what about the neck/fingerboard? Does this matter? - since the string attaches to the wooden body at one end, and the wooden neck at the other, either via fret or nut. Body and neck - both solid bits of wood - are perhaps analogous/similar in respect of influence on tone, or lack of it. I can't see why they wouldn't be anyhow. So maybe I could swap the '62 strat's neck for any other of the same dimensions, and still do nothing to degrade the tone.

At which point we're basicaly left with the guitar's hardware, and the pickups - hardware can easily be upgraded these days, and there are fine pickup makers around, able to replicate vintage pickup specs, or produce designs of their own. So this implies to me that someone with a sensibly upgraded Squier strat, or other copy, is no worse off than the owner of the '62 strat... I suppose quite a liberating thought for the more cash-strapped among us.

And also, that pickup makers are hugely important people - even more so than we might already believe, and the cost of quality pickups is utterly justified, as this is one of the few things on the guitar itself, that can influence the tone.

As it happens, I'm a fan of upgrading pickups anyhow, and to be clear, I'm not convinced at all that body (or neck) wood has no discernible influence - but I would genuinely be interested to know how far you agree with the reasoning above TCS.

Three-ColourSunburst

Rabs said:

Well their debunking is just as dodgy as any of the so called tests to prove it.. He may seem like hes talking sense but that doesn't make it so. This is the issue.  Theres no real proof either way...

Just take a look at the academic research I linked to. Here are the academic and research records of the lead author and supervisor, who work at the federal university of Parana in Brazil, which has a specialist school of luthiery.

https://www.escavador.com/sobre/8006405/rodrigo-mateus-pereira

https://www.escavador.com/sobre/5917495/thiago-correa-de-freitas

http://www.luteria.ufpr.br/portal/

Perhaps Homer should have the last word?

Sassafras

Good morning everybody, I just thought I'd pop-in to see if the patient was still alive

I'd hate to go guitar shopping with you @Three-ColourSunburst ;
It must be a very grim and joyless experience.
As well as a long drawn out one if you insist on taking all your scientific measuring equipment with you.

richardhomer

Sassafras said:

Good morning everybody, I just thought I'd pop-in to see if the patient was still alive

I'd hate to go guitar shopping with you @Three-ColourSunburst ;
It must be a very grim and joyless experience.
As well as a long drawn out one if you insist on taking all your scientific measuring equipment with you.

I think he's permanently changed my buying habits.

I'll be testing the frequency response of every guitar I try from now on. As if I haven't got enough to carry into a guitar shop already, with my scales and calipers to measure the depth of the neck....

OilCityPickups

Megii said:

So - I've been thinking about this, and specifically the implications, just supposing @Three-ColourSunburst is correct... If I understand right, it would mean, for example, that:

I could take a treasured 1962 strat ("amazing responsive instrument, fabulous tone, just sings" etc.) and replace the body with anything of the same dimensions (a cheap copy off ebay? plywood?) and the guitar would sound just the same. Also, as a side note: issues about thick poly finishes vanish, since this is just part of a guitar body that can have no influence anyhow.

And then I think, what about the neck/fingerboard? Does this matter? - since the string attaches to the wooden body at one end, and the wooden neck at the other, either via fret or nut. Body and neck - both solid bits of wood - are perhaps analogous/similar in respect of influence on tone, or lack of it. I can't see why they wouldn't be anyhow. So maybe I could swap the '62 strat's neck for any other of the same dimensions, and still do nothing to degrade the tone.

At which point we're basicaly left with the guitar's hardware, and the pickups - hardware can easily be upgraded these days, and there are fine pickup makers around, able to replicate vintage pickup specs, or produce designs of their own. So this implies to me that someone with a sensibly upgraded Squier strat, or other copy, is no worse off than the owner of the '62 strat... I suppose quite a liberating thought for the more cash-strapped among us.

And also, that pickup makers are hugely important people - even more so than we might already believe, and the cost of quality pickups is utterly justified, as this is one of the few things on the guitar itself, that can influence the tone.

As it happens, I'm a fan of upgrading pickups anyhow, and to be clear, I'm not convinced at all that body (or neck) wood has no discernible influence - but I would genuinely be interested to know how far you agree with the reasoning above TCS.

And if you believe another argument, then high priced pickups are a waste of time as your average ... insert name of favorite  cheap brand here ... are just as good. This argument is put very vociferously in some quarters.
Actually I'm a believer that there is a brice above which you don't get better pickups, just prettier ones with more bells and whistles and more 'mojo' if you like. They are just wire and magnets in the end ... and compared to measuring what's going on with 'tonewoods' measuring the tone spectrum of a pickup is both child's play, and repeatable and predictable. The 'art' of pickup making is in being prepared to experiment, make notes and analyse ... so to me, it is really more science than art.  
Oh, and I am son of an engineer and grandson of an engineer ... I see what I do as science backed up with good engineering! 

NelsonP

Sporky said:

Three-ColourSunburst said:

For resonance to selectively preserve or enhance certain harmonic frequencies in a way that consistently affects the timbre of the sound, it would have to resonate in a way that affects all frequencies / notes in the same way.

An object cannot resonate at all frequencies equally - that's not resonance. Look up formants.

C-, must think more clearly.

I think most rock music is built around the same base notes and intervals e.g. G, C, D and or E, A, B.

So it's just a theory, but maybe the guitars that most folks think are great just happen to be made out of wood at the right size, shape and density to provide a little bit of resonance through the body at those frequencies (eg 330hz, 440hz) and the harmonics of them.

It would be pretty easy to test this in a lab, with the right equipment. It's essentially just a frequency response curve for the guitar body.