How much does an electric guitar's body physics affect the tone, playability, etc?

Question

It makes sense to me based on having some knowledge of physics that on an acoustic guitar the body (and neck, bridge, etc) materials and design has a huge effect on what the guitar sounds like.

But on an electric, as I understand it, the strings don't resonate much with the body (and neck, bridge, etc); they're just there to oscillate a magnetic field on the pickups, and besides the body (and neck, bridge, etc) is usually pretty solid anyway so not much change for the small force of fingers on strings to resonate such a dense object.

Is that correct? Do different electric guitars have significantly different sound purely as an effect of their bodies (and neck, bridge, etc)?

Answer 1

On a solid body guitar the body shape and wood don't matter much. The most important thing about a guitar is the mechanical impedance as seen by the string. The string start vibrating and the rest of the guitar sucks out energy at different rates at different frequencies. This is determined by the mechanical losses in the overall force chain: bridge, body, neck joint, neck, & saddle. The body itself is rigid and hard and so the mechanically impedance of the body is small as compared to the other contributors.While a slab of mahogany as a lower impedance than a chunk of Alder, both are small as compared to the impedance of the other parts of the mechanical chain, so the differences don't matter much.

Answer 2

Paul Reed Smith has videos available where he talks about the effect different woods have on the sound of his electric guitars.

(starting about 2:47 into the video)

He demonstrates by tapping the rosewood neck and fingerboard and mahogany body blanks. If the wood was pine or balsa it wouldn't sound anything close to what you'll hear as the wood resonates because the wood would absorb the vibrations instead of resonate with or reflect them.

Instrument builders over the last several hundred years have learned that certain woods have certain effects on the instrument's sound, whether it's a drum, a clarinet, a violin, a piano, or a guitar. The density of the wood controls its sound, and its ability to resonate and reflect or absorb the vibrations caused by the string vibration, or the column of air, or the strike of the membrane. The builder relies on those to control the sound of the instrument.

The woods aren't just ornamental, as the idea that wood has no affect on the sound would imply, otherwise we wouldn't see so many common uses of certain woods for caps or bodies.

(starting about 1:30) has more on how PRS guitars are picky about the wood and that it affects the tone and 4:30 for PRS himself talking about the wood affecting the sound.

Similarly, Rob Chapman discusses how wood affects the sound of his guitars in

One of the things I do when auditioning new guitars is to play them without plugging them in. That lets me hear how the guitar itself affects the sound. Take two identical electric guitar models that are identical in their wood types, play them "acoustically", and you can often hear differences, even though the strings, frets, tuners etc. are supposedly the same. At that point, the difference is very likely the wood.

So, don't discount the effect of wood and wood quality and a luthier treating it right.

Answer 3

The debate about tone woods is basically a sort of religious war - the sort that arises between people who are perhaps overly passionate about a subject. Like Macs and PCs, VHS or Beta Max, GM or Ford, it's just one of those things that is going to divide people.

Seems to me the science leans towards the 'negligible difference' guys (and I suspect 'negligible' is a better answer than 'none'), but there is a very small amount of actual scientific, controlled, experimental evidence to prove the case either way. The Chapman video is an attempt to show what most people in the business of selling the difference between a $300 guitar and a $3000 guitar believe to be true, but on it's own it's not good enough. Guitars may have identical specs, but without testing more guitars to see the random difference from guitar to guitar based on differences that might arise in manufacturing, it means very little.

To do a test that could actually be scientifically accepted, you'd need to test the sound of a guitar where the only thing that changes is the wood. All other variables have to remain the same. Same nut, same bridge, same setup, same wiring, same glue, same screws. Two 'identical spec' guitars are not close enough - it needs to be the same guitar with nothing changed but wood.

A better test would be to simply screw a pickup to a block of wood and set up a single string (not need for a nut or bridge - a couple of knife edges would do. Record the sound wave accurately using a computer oscilloscope via a pickup, not a human ear through YouTube. Change the wood - but nothing else. Everything else needs to stay the same to the millimetre or less. Look at the magnetic 'sound' wave produced by the cable (no need to actually listen to sound, as that's just adding variables introduced by an amp).

Repeat with many versions of the test woods, not just one subject. Compare the variation in tone produced by 'guitars' with the same wood vs variation between woods, and see if the difference is statistically significant.

My guess would be that, properly tested, the difference would be negligible. My reasoning is that solid body electric guitar pickups, and indeed solid body guitars, were designed specifically with the intention of NOT resonating. Early guitars had massive feedback issues - so they cut out the resonant boards, and designed pickups that were meant to 'pick up' only the magnetic distortion created by a moving string, and nothing else. But that is only my hypothesis completely untested by valid experimental data. I doubt anybody has done a proper test, but I'd be interested to see one if they have.

As a control you might include a variety of 'strings' which are stung to some sort of non-resonant surface that is not wood at all, to prove you can actually reproduce multiple instances of identical sounds in identical circumstances when something is set up by human hand.

What we have instead are some very angry people (who, by the by, should maybe consider getting out and relaxing more) competing over whiteboard drawings to 'prove scientifically' one side or the other. Real scientists know that the proof is through experimental data, not whiteboard hypotheses, however well constructed.

Answer 4

It depends on who you ask. Some musicians swear up and down that one tonewood is far above the rest. While the woods and materials involved do affect the sound, its so slight that most people could never tell the difference.

The pickups and strings are what really control your sound on the electrics, as does other factors such as pickup height, string gauge/type, etc...

As far as playability, thats purely on the build of the guitar, as a poorly built guitar will feel and play like a poorly built guitar. It may sound just as good as that $4000 custom built top-of-the-line premium guitar, but it will NEVER feel like it.

The only thing that the 'Body' consists of, is a shaped slab of wood with no hardware in it. Hilmar was correct to list each part separately because they're all unique parts of the guitar(making a special case for neck-thru guitars, where the body includes the entire neck), and as such, fulfill unique tasks. Your question is somewhat broad, but not unreasonably so.

You won't notice so much difference in tone between woods, only your sustain (Although, string age and bridge construction both factor in as well) will really be affected, but its hard to pinpoint it as just the tonewood or just the bridge, or just the strings, as they all weigh in on the equation.

Basically, with the right parts and enough patience, you can make a piece of plywood sound close to a $4000 guitar, but your hands will absolutely notice the difference, where a listener won't hear it, especially not one who hasn't trained their ear.

Answer 5

Some electric guitars are "lively" and sustain forever while others "die like dogs" (even with brand new strings)?

I used to wonder about all of this too until I was offered an explanation by a wise old bass technician.

He told me that what makes all of the difference is not the type of wood used but rather the relationship between the "notes" produced when you turn the guitar over and tap the neck and the body of the guitar (with the tip of a finger - On a guitar that's made of more than one piece of wood then the section that has the bridge is the crucial part)

If the difference makes what you tap sound like a set of bongos then the chances are that you've got a "live" one? He went on to explain that it was about "sympathetic" wave forms and strong intervals like octaves and fifths versus an unsympathetic combination of notes that would fight each other and cause the picked notes and chords to die sooner.

He also said that this explained why so many old fender necks from the early days ended up attached to a different body to the one that they left the factory with. Simply by swapping necks it is possible to turn two "dogs" into guitars that will sustain for ages.

This works for me and explains why when playing without an amp some guitars are "putter downers" while others long to be played?

Answer 6

There is a lot of debate on this subject but I will try to do my best to answer to this question and explain my position.

Based on my knowledge and experience, there is no audible difference in tone of the guitar because of how electric solid body guitars work.

As you said, in electric guitar, signal is generated in pickups by disturbing its megnetic field with metal strings.

If someone claims that pickups pick any of guitar's body vibrations, try using nylon strigs on electric guitar and you will hear nothing (if you hear anything then your pickups are broken)

Another test is to turn the volume down to zero (or unplug your guitar) and touch something that resonates (and is made of wood preferably), eg. cupboard or a piano with tip of your guitar's head while playing. You will easily hear that while touching the cupboard, vibrations are transfered to it so thus the guitar becomes more audible acoustic-wise. By touching the cupboard, your guitar becomes one with the cupboard and resonates as one big acoustic instrument. Now, turn the guitar and amp on and do the same thig: play a chord, listen how it sounds and while it is still going, touch the cupboard. You will hear NO difference from the amp, no matter how the guitar sounds acoustically because the sound is coming from the pickups and strings only, not from the wood! Of course, you could try some more destructive tests like chopping off a part of the guitar body (so it affects the accoustic tone, right?) or gluing/screwing the guitar to your desk or floor.

So, how is possible that two guitars sound different? The answer to this question is easy once you forget about all the "facts" that most of the guitar manufacturers say.

First of all: setup - to get similar tone, all pickups need to be set in the same distance from each other and from strings. All strings need to be of the same gauge and type, also in the same distance from the fretboard.

Another, and the most important thing is that you have to know that all passive electronic components (i.e. resistors/pots and caps) are made within a range of tolerance (eg. 1% 5% 10% etc.):

https://en.wikipedia.org/wiki/Preferred_number#Electronics

These components are present in your guitar (tone and volume control) and do affect the tone. Also, the wire and magnets used to make pickups can vary to some extent.

This is the factor why the "proof" posted here:

How much does an electric guitar's body physics affect the tone, playability, etc?

is invalid because these two guitars had different electronics (of the same type but not exactly the same).

It would be scientifically better to take two guitars made of different wood, play some chords on one, swap ALL the electronics (including pots), measure the distance between strings, pickups etc, then record some chords, repeat the process about 10 times or so and then do a double-blind experiment.

So, if there is no difference, should all guitars be made of one type of wood (possibly the cheapest one or a plyboard)? I say no. Here's why:

• visual difference (a matter of personal preference)

• mass (some players prefer lighter, some prefer heavier guitars)

• other physical aspects like durability, humidity and thermal expansion of wood

• and more.

To get a decent sounding guitar, you should worry more how well it is made and not what wood it is made of.

Answer 7

In my experience I would say that the last thing you would want from a solid guitar is for the body wood to absorb any of the sound the string makes (you can get Perspex body guitars!) The usual magnetic pick-ups generate a small voltage in their coil/s when the string moves or vibrates in the magnetic field of the pick-ups magnets - vibrating wood is not picked up any more than the vibrations of nylon strings is. To me, the main criteria of a solid guitar is for it to be dense and rigid enough for the string to vibrate to its maximum. The moment the wood starts to vibrate as a result of the string vibrating, the string vibration is being damped and is being sent in the wrong direction i.e. away from the pick-up. Now, a piezo pick-up is a different matter altogether because these do pick up body vibrations made by nylon strings and body wood - with an acoustic instrument this would be particularly marked and in the case of a solid instrument probably to a much lesser extent. I've heard great guitarists get an amazing sound from a cheap instrument and I've heard expensive instruments produce dire sounds from poor guitarists! I reckon there is a bit of a mystique that has been created here which is commercially important to perpetuate.

Answer 8

Presently I add can one subjective bit of experience. After I built my custom Tele (1/4" quilted maple cap over chambered mahogany body, with a 1-pc maple neck), I was disappointed with original acoustic sounds. Upon fitting a Tusq nut, it brightened pleasantly. Then I fitted Tusq saddles, and it improved further.

My experiment did not vary the tonewood, but it DID alter the most significant elements of the string-to-body interfaces -- the nut & the bridge saddles. The results were audibly noticeable. Surely there would be measurable as well.

As far as the tonewood effects, you would really need an A/B experiment to offer any scientific feedback, provided that you can keep all other variables equal. And there are many variables to manage.

Answer 9

You might well argue that Paul Reed Smith is simply encouraging people to purchase really expensive Private Stock models, but the same cannot be said for Rob Chapman who deliberately produced a quality, affordable guitar. The website for Carvin guitars gives lists of available body and top woods for their custom-built guitars, together with a detailed description of how that wood affects the guitar's tone - it doesn't strike me that they have an axe to grind, either. I agree with the comment that the debate about tone woods is a bit like a religious war with one definite reservation - to me the religiosity is almost exclusively one sided: to non-believers it's "I don't believe that the type of wood can possibly affect an electric guitar's tone, so it doesn't, period". On the other side, it's more like "Screw your beliefs, I build/repair guitars for a living (or I own/play a lot of them) and I KNOW the type of wood makes a difference because I can HEAR it!"

Answer 10

The question is "does the body of the guitar affect the tone?". The tone is composed of many frequencies which are present on the vibrating string. I believe there are two things that need to be answered to know if it does.

1. What is the amplitude of the reflection coefficients at the two boundaries (the nut and the bridge) from 0 to 20 kHz on two identical guitars except for one parameter ( i.e. their bodies made from different wood)? If this is known, then it would let us know how much of a particular frequency makes it through the boundaries and how much is reflected.

2. When the guitar is strummed, the body vibrates and therefore the pickup vibrates. This will affect the magnetic field around the pickup. The physics is the same (Faraday's law) regardless of which is moving relative to each other( i.e. the pickup can move relative to the string or the string can move relative to the pickup to cause a change in the magnetic field and thereby a change in the voltage). How will the vibration of the pickup change the output voltage of the pickup, and is it different on the two guitars?

Answer 11

I don't know if the material and construction of the body and neck lead to non-trivial differences in the sound achieved or not. The vibrations travelling through the materials clearly will behave differently but whether that difference is non-trivial compared to how the strings interact with the nut and bridge, the pickups & electronics, I have no idea.

But what I can say is that if it is the case, then this will be affected by holding the guitar, and how your hold changes as you play. If you grab a vibrating metal rod, the vibrations stop almost instantly as your hand damps them. The same effects would affect your guitar... how tightly you hold the neck, where you hold the neck, etc. When you play a standard F on the first fret, and then play a D using the F-shape on the 10th fret, you will be affecting differently the way vibrations travel through the guitar and how they are damped. If you just pluck an open string with your hand grabbing the neck, and repeat without touching the neck at all, you would/should hear a difference in this case.

Answer 12

The body wood on an electric guitar makes little to no difference. 99% of you would agree. Especially if you were in a room, blind folded, and just asked by sound to say what type of wood is used or if the demonstrator switched to a different guitar. In fact, I've seen it where someone straps on and plugs into one of those plexiglass guitars. Everybody that was blindfolded and asked to guess what type of wood the guitar was made out of answered wrong. Also, take note of the fact that many guitars will be plugged into stomp boxes, effects etc. and also played with very high gain. At that volume, you just hear a massive wall of distortion (which isn't a bad thing). Especially at that point, the type of wood won't matter one bit.

Answer 13

For simplicity's sake (and as a viable comparison) think of it this way:

Does changing the material a microphone stand is made of change how the microphone picks up noise of any type or when a vocalist takes the microphone out of the stand and holds it, does it sound differently?

The easiest and most accurate way to prove or disprove this is as follows:
Compare several strat bodies of different material including but not limited to:

• Plywood
• Alder
• Ash
• Pine
• Acrylic
• MDF

Use the same neck, bridge, loaded pickgard, strings, tuning, pick, cable, amplifier, and settings (all pickups, pots, screws, tuning, and electronics reused on each body in the exact same pickgard).

Compare each sound curve,compare db and use any other viable sonic comparison analyze the data and for the love of music put this damn argument to rest. This honestly does not seem that difficult, I've personally got most of the required items other than the multiple strat bodies.

Preferably use a looped sample and use a scope / visual equalizer and view and compare the sound curves, peaks and low points and let us all know.

Answer 14

Wood is the most important. If you don't believe it, compare the Gibson Les Paul, SG and 335 models. They have the same hardware, pickups, scale etc. The only difference is body wood, yet they sound completely different.