“Does Tonewood Affect My Guitar’s Sound?”
This is the age-old question that probably causes the most amount of arguing between luthiers and guitarists (other than the question of whether or not there’s a difference between types of capacitors).
Some would say that the fact there’s even debate over tonewood properties would be enough to say that it’s inconsequential. For the most part, I think that’s a pretty rational point of view – but I also believe the issue isn’t that simple. I have my reasons for not completely dismissing the consideration of tonewood selection and preferences.
I’d like to bring your attention to this video – the sounds are recorded on identical setups and pickups with differing woods. The results are actually more profound than I would expect, more than my article gives credit for. But taking into account a very small +/- in pickup height and location, I’d say it’s everything I’d expect.
Considering Properties of Wood
To consider the matter, let’s pan out for a moment and look at how tonewood affects acoustic instruments.
It’s a general rule of thumb that the more dense the wood, the brighter the tone. Softer woods will have a darker tone with less bite. This is because the wood itself is mimicking the string’s vibration at two separate points:
- Mechanical energy transferred from direct contact with the string (at the bridge and nut).
- Mechanical energy transferred through the frequencies in the air molecules reverberating in the chamber (and above the sound hole to some degree as well).
The ability of the wood to transfer mechanical energy is its value – denser wood is not as flexible as more porous wood and responds much more easily to higher frequencies. Porous wood absorbs more of the higher range, responding better to bass frequencies.
These same principles are being applied to electric guitars, but a major factor is removed: there is no reverberation of mechanical energy through the air molecules. Electromagnetic pickups function by detecting the change in the magnetic field the poles create, which are directed upward at the string.
Tonewood Critics Are Satisfied
Critics of the tonal values of wood in electric guitars are often pleased to end their arguments here, placing all of the tone’s value the pickups after the mechanical energy of the string’s vibration is transduced into electrical energy – from the string and nowhere else.
And they’re right, up until the idea that the guitar’s strings aren’t being affected by their own reverberation.
I believe there is an amount of reciprocal energy being transferred back into the string. Even though the mechanical energy from the frequencies reverberating in the air has been removed from the picture, there’s still energy to consider from direct contact with the string.
How much energy exactly?
Let’s make a miniature amplifier to test it out! Pick up an electric guitar and face the strings at the wall, then pluck an open E…just about nothing is bouncing off the wall to make much of a difference in volume.
But place the end of the headstock against the wall and pluck the same string. Suddenly, you’ve increased the volume significantly – all from direct transfer of mechanical energy from the string, through the bridge and nut, through the wood, and into the wall – which then vibrates and reverberates the tone inside itself since it’s hollow like a soundhole.
That’s a significant amount of energy and I don’t believe it should be discounted at all.
Part 2 of this demonstration involves a tuning fork. Tap it and place the un-forked butt end on the body of your guitar to see the energy transferred into the strings through the body.
This is a form of sympathetic resonance – its presence is undeniable in any stringed instrument. So that’s my evidence for tonewood: there’s a resonant relationship between the strings and body when energy is transferred into the wood through direct contact, and then having it returned through the same points of contact.
If the woods have different consistencies then it goes without saying that the energy returned to the strings will have a new harmonic spectrum based on what the wood was able to transfer.
I’m no physicist, but it looks like everything is there to support my argument so far.
But How Significant is this Reciprocal Energy?
I can’t give you a definite answer there, but considering that this is all occurring at a stage before induction to electrical energy, we can assume that whatever goes into the pickups is going to be affected much more by the time it’s amplified back to you.
We also need to accept some other facts: the guitar’s finish, weight reduction / hollow-body routing, bridge & nut material, and string material & thickness would also be playing a role in this…anything in the chain of things that eventually contact the string. We also know that the tonal differences are small enough to have a debate over.
It’s highly unlikely that someone would be able to listen to a few recordings and be able to pick out which one was played on a swamp ash body, or a guitar made of Plexiglas.
But just as in the winding of pickups, those subtle variations in composition and material will most definitely change the overtones and produce a number of pleasing details. In the case of pickup types, we know that they can mostly be identified in comparison to each other. With tonewoods, they’re details that may be difficult to discern in an A/B test to most people.
Convincing Not Required
To the player, I think the differences can be quite important. Wherever you’re standing in this argument, I think there’s another important aspect to consider: the way the wood has a reciprocal transfer of energy to the strings is identical to the way a person’s experience with a guitar is reciprocal and can change the way they feel and play.
In that sense, if someone believes that the wood has absolutely no effect on the guitar’s tone, I would say it’s still not a reason to dismiss tonewood preferences.
Some people do take it a little far though…