Thread: Aussie wood for electric guitars

So how is it producing that sound, given that a pick up theoretically has no moving parts? I think you can also get a similar sound by tapping the body.

What I'm saying is that if you tap a pick up, you're inducing vibrations in it that are not associated with the strings moving through the magnetic field, but something is causing a current to be generated in the coil, which is then amplified.

Or is the sound we hear from the pick up in that case something else?

True, you are inducing current without the aid of the strings and "theoretically" it has no moving parts but the bobbin is flexible and I would suggest when you strike it you are causing the magnets to move even if it is ever so slightly, within the coil.

The reason I keep mentioning pickups that are "microphonic" it that when the coil becomes loose due to break down of the dope on the wire it is then possible for the pickup to behave more like a microphone, that is, that even sound waves can move the coil in relationship to the magnet. It could also happen if the magnets are a little loose in the bobbin but this is undesirable in most cases for a electric guitar.

Jim

So I guess there is scope there for vibrations through the neck and body to directly contribute to the signal at the pickup, and therefore the nature of the timber would have some bearing on this.

The question is how significant it is (assuming it exists). Someone should strap a pickup to a body well away from the strings and see what, if any, sound comes out.

Originally Posted by silentC

So I guess there is scope there for vibrations through the neck and body to directly contribute to the signal at the pickup, and therefore the nature of the timber would have some bearing on this.

I feel like I am going over already covered ground. That wood or the materials the instrument is made from contributes to the sound is not in question. At least not to me.

Originally Posted by silentC

The question is how significant it is (assuming it exists). Someone should strap a pickup to a body well away from the strings and see what, if any, sound comes out.

In your suggested experiment how do you suggest to excite the body given the absence of strings?

Jim

I feel like I am going over already covered ground

Sorry, it's probably in that 15 pages somewhere. I was just thinking aloud about pickups.

In your suggested experiment how do you suggest to excite the body given the absence of strings?

No there are strings, but the pickup is not underneath them. Maybe it's attached to the back of the guitar, so that the only way it can generate signal is through direct vibration from the body. Then you just play it like a normal guitar and see what you get at the amp. If you get anything, it would be the "sound" of the body and neck.

Originally Posted by silentC

So how is it producing that sound, given that a pick up theoretically has no moving parts? I think you can also get a similar sound by tapping the body.

What I'm saying is that if you tap a pick up, you're inducing vibrations in it that are not associated with the strings moving through the magnetic field, but something is causing a current to be generated in the coil, which is then amplified.

Or is the sound we hear from the pick up in that case something else?

A few comments:

1. as Jim points out many old or badly build pickups will generate a signal when physically bumped. This is not the pickup working as a microphone.
2. if you're getting a signal out of a pickup when you tap the body of the instrument then it's either parts of the pickup moving relative to the coil or the vibration is being picked up by the strings and they are in turn generating a signal in the pickup.

Ahhh, okay I see, you wont get much. If the PU is microphonic then you will get sound but it is a rare guitarist that works with microphonic PUPs.

If you can mount it in a way that the vibrating body can physically move the magnets in relationship to the coil then you will get sound as in the way the blow from the plectrum works but if the body simply moves the magnets and coil in unison then you get nothing.

I will add that when it comes to something like a Tele the bridge PU is surounded by the ferrous metal bridge and if you set the PU vibrating in relation to the bridge plate then you will again get sound.

Jim

if you're getting a signal out of a pickup when you tap the body of the instrument then it's either parts of the pickup moving relative to the coil ...

That's how a microphone works.

... or the vibration is being picked up by the strings ...

That's why I asked if it still does it with the strings off. I've never tried it. I'm not even sure how common that is. I'll have to check it out next time I play a gig.

You can as mentioned above hold a pickup in your hand and thumb it and it will make a sound, this is simply the fact that the magnets that sit in the pickup are floating (albeit very little) they are a firm fit, they are not fused together or to the bobbin. Any movement of the magnet will craete a induced electromagnetic field in the windings around the magnet, this is whats causing the sound your hearing

Originally Posted by simso

You can as mentioned above hold a pickup in your hand and thumb it and it will make a sound, this is simply the fact that the magnets that sit in the pickup are floating (albeit very little) they are a firm fit, they are not fused together or to the bobbin. Any movement of the magnet will craete a induced electromagnetic field in the windings around the magnet, this is whats causing the sound your hearing

Jeez, how confused can a simple explanation get.
Physics anyone ?
Movement of the magnet will not induce electromagnetic field. Current through the bobbin winding will induce magnetic field.
Movement of the magnet will cause movement of or a change in magnetic field relative the wires in the bobbin which will induce current through bobbin winding. This current is signal. This signal is created by physical movement within the pick up itself.

Normally guitar pick-up is not designed to produce signal by mechanical excitement.
Good production techniques and practices reduce this side effect. As with all things not ideal but real world, we will have variations in pickpu's that will create a sound of the pickup. different coating of wire, air or wax filling, material of bobbin will contribute differnt dielectric properties affaecting the inductive or capacitive components of the LC network that the guitar pickup is. few windis more or less will also affect the LC network as will difference in scatter winding as opposed to neat laying of windings.

All of these factors contribute to the specific sound or flavour or whatever you want to call it but essentially it is specific frequency response of a given pick-up, and not just a frequency response to a simple sine wave excitement but to a complex signal.

Then there are different magnetic materials with differing properties that will also affect the above mentioned pick-up sound.

And as much as that is interesting and as much as some people like to bring it up, that is not the subject of this thread,
This thread is about the impact of timber onto the sound of electric guitar.
There was a lot of religious like posturing and convincing going on ...

Let me have a try at theoretical approach that could be tested...

let's take the pick-ups out of the guitar and strum it.
If we suspend strings on two infinitely rigid points ( meaning that they cannot transfer any energy away from the strings ) we will hear strings and nothing else will influence that sound. We that put a pick-up close to those strings and we have a guitar that simso is talking about.

As soon as we introduce real world into this story we have a real guitar with a specific frequency response. Absorbing energy from the strings and returning some of that energy back through resonance.
There was talk about dead spots in frequency response. Those are not just attenuating particular tones they are attenuating specific frequency and affecting harmonic components of all tones.
The guitar will affect the vibration of the strings and that will be picked up by the pick-up. Pick up will not be excited by the vibration in timber (not a great degree anyway).

Now if you plug the guitar into an overdrive channel and turn it up, there is little chance of hearing that fine difference that timber makes. If you distort it enough the pick-ups stop making any difference as well and you cannot tell any more if you have selected a neck or a bridge pick-up

Let me try to summarise my point of view, timber will make difference to the guitar and the sound it produces, that is not a matter of belief but a matter of physics.

Is that difference important? That can be debated or made a cause of a religious war

confused

Originally Posted by stolar

Movement of the magnet will not induce electromagnetic field. Current through the bobbin winding will induce magnetic field.
Movement of the magnet will cause movement of or a change in magnetic field relative the wires in the bobbin which will induce current through bobbin winding. This current is signal. This signal is created by physical movement within the pick up itself.

Okay some basics then

Moving a magnet near or over a wire will induce an electrical signal its as simple as that, if you dont understand that much then nothing I can say or point you too will explain it better for you, if after youve wound hunderds of coils you still think the same then I would be exceptionally surprised

The technical side

Moving a magnet near a wire will create a mechanical cutting motion of the flux lines from the magnetic field of the magnet itself, that mechanical motion creates minute little electrical signals in the wire, these are called eddy currents, the flow of eddy currents (electricity) generates its own magnetic field (remember the hum of power lines) the two magnetic fields the one from the inducing magnet and the new one from the wire itself compete against each other this is called inductive reactance, inductive reactance is used to generate controlled signals which can be used in every day life such as the inspection of aircarft for defects and cracking or making a signal to come out of a guitar

Neck sustain is something entirely different and is mute in this argument becuase everyone agrees that wood selection for neck thickness grain orientation ect will cause the strings to flex differently, however I would like to seee what flex you can achieve out of the body section

Originally Posted by stolar

And as much as that is interesting and as much as some people like to bring it up, that is not the subject of this thread,
This thread is about the impact of timber onto the sound of electric guitar.

As far as this thread, if you go back to the original opening question it is different to as you quote this thread is about,

Originally Posted by Nobus

So here is my question: What Aussie woods can be used in the construction of a solid body electric guitar? What is good for the body, the neck and the fretboard.

the young fella wants to know what wood he can use for building an electric guitar, the thread has digressed since then as to the relevance of the material used for the body of the guitar.

Originally Posted by stolar

Let me try to summarise my point of view, timber will make difference to the guitar and the sound it produces, that is not a matter of belief but a matter of physics.
Is that difference important? That can be debated or made a cause of a religious war

You will note I previously have said

Originally Posted by simso

Not wanting to be debateful but there are two sides to every story and every theory. The fact of the matter is IMO, that the wood choice for the body section of an electric guitar plays a very minor and we are talking minor role in the generation of an electromagnetic sound, the pickups play the most important part.

Example if I make a body out of plywood (and I am a commercial luthier) and a body out of jarrah and one out of pine, paint the body and give it to a player, they will find it difficult to almost impossible to tell which is which. However If I was to wind a coil (and I manufacture coils) and wound it to 4000ohms and 8000 ohms and 12000ohms I guarantee you they will hear a difference. The point being wood selection for the body does play a role but the role is so inconsequential that it is almost immeasurable IMO.

I personally am a fan of beauitful wood and the uses of it over ply for the body but this is mearly for an aesthetic point of view

Originally Posted by simso

Okay some basics then

Moving a magnet near or over a wire will induce an electrical signal its as simple as that, if you dont understand that much then nothing I can say or point you too will explain it better for you, if after youve wound hunderds of coils you still think the same then I would be exceptionally surprised

you have talent for pointing out irrelevant ... (and not reading before responding)

movement of magnet is irrelevant, it is a change of magnetic field that induces current in a wire that is in that magnetic field ...
your previous post confused an induced magnetic field ( you incorrectly called it electromagnetic ) and induced current. Permanent magnets in guitar pick-ups have permanent magnetic field and movement of the magnet does not induce electromagnetic or magnetic field. I assumed that you have understanding of the electro-magnetics over and above what you noticed while winding pick-ups.

in a guitar pick-up there is no movement of the magnet, it is the movement of the steel string in the magnetic filed that creates the changes in the field and hence induces corresponding current... the signal...

why are you hell bent on trying to convince us that your opinion is the truth and all the while not providing any relevant proof or even evidence to support it ..

you think that material that electric guitar is made of makes no difference, that is fine, but that does not make it "the truth"
Just because you have not heard it make any difference does not mean that there is none..

and while your opinion is quite valid you have to allow others to have equally valid but differing opinions ..

you have not provided any proof in this dicussion so far that your opnion is more valid then those opposing you ..

Originally Posted by stolar

you have talent for pointing out irrelevant ... (and not reading before responding)

Not at all, I read the response, but when someone uses my post as a debating point Im more than happy to enter the discussion

Originally Posted by stolar

movement of magnet is irrelevant, it is a change of magnetic field that induces current in a wire that is in that magnetic field ...
your previous post confused an induced magnetic field ( you incorrectly called it electromagnetic ) and induced current. Permanent magnets in guitar pick-ups have permanent magnetic field and movement of the magnet does not induce electromagnetic or magnetic field. I assumed that you have understanding of the electro-magnetics over and above what you noticed while winding pick-ups.

Interesting, movement of a magnet can and does create eddy currents in a wire in close proximity. Calling it an electromagnetic field was not incorrect, for simple definition an electromagnetic field is a magnetic field created by the movement of electricity (or eddy currents), example the induced electricity from the movement of the magnet in the pickup windings has now created an electromagnetic field, but thankyou for trying to correct me, I recommend if you dont understand the full concept of something then dont correct others who do understand it.

Originally Posted by stolar

yin a guitar pick-up there is no movement of the magnet, it is the movement of the steel string in the magnetic filed that creates the changes in the field and hence induces corresponding current... the signal...

I do not disagree with this, however the question was raised why am I hearing a signal when I tap the pickups, maybe if you read the posts and there relevance to each other you would have an answer before feeling the need to post

Originally Posted by stolar

why are you hell bent on trying to convince us that your opinion is the truth and all the while not providing any relevant proof or even evidence to support it ..
you think that material that electric guitar is made of makes no difference, that is fine, but that does not make it "the truth"
Just because you have not heard it make any difference does not mean that there is none..

Im not bent to say my answer is the truth, you will note if you were to read the earlier posts It was IMO, however to may people say it makes a difference yet cannot and do not provide any proof either. But again thankyou for targeting myself

To this end my oriignal post was

Originally Posted by simso

Nobus, in regards to your original question, the wood selection for an electric guitar is really irrelevant, you can use plywood if you really want and paint it.
Wood selection however is really importamt on acoustics violins etc

All subsequent posts were in regards to answering questions or discussing views

Originally Posted by stolar

you have not provided any proof in this dicussion so far that your opnion is more valid then those opposing you ..

Agreed, however do note I repair guitars for a living, I dont manufacture them, I dont sell wood for them or anything along those lines, so there is no commercial gain attached to my comments. As a repairer I see a pletharard of different setups designs etc, Im the one, people like yourself who reads an internet forum and becomes an expert over night goes too, to have there guitar fixed. So I feel I certainly have the right to make a comment regarding wood and pickups IMO

Gday Guy's,

Severe storms are limiting my access to the internet both yesterday & again today by the looks of it.

I'll try to reply a bit later to some very good points made after my last post, I have a few more test results to point out several things of interest.

It is just a matter of Physics.

WayneW