Electromagnetic pickup and micro phonics, tone, wood, pick attack etc....

[TomBruner]

Just a thought, but on a hollow body, especially a jazz box or such, wouldn't the harmonic vibrations of the face alter the distance between the strings and pickups? Yes, minutely, but still, creating a slight Doppler sort of effect? This would most definitely affect the wave shape produced by the pickups.

[David Schwab]

I'm not sure if I'm being redundant in suggesting that the finish of the wood is an often overlooked quality as well. I always felt like it was easy for a manufacturer to hide poor wood quality by burying it under an thick coating of resin. To me, it's like falsifying the hardness of the wood. I know most people probably just think of it terms of a protective coating not considering how it changes the way the strings vibrate against it.

The finish has no affect on the tone of a solid body guitar. And what's "poor quality" wood? What would make a certain piece of wood better than another for a guitar? More expensive wood generally looks better, or it's harder to get. That's about it. Fender chose alder, ash, and maple because they were cheap and easily obtainable. Honduras mahogany used to be easy to get but was over harvested. Same with Brazilian rosewood. Alternatives exist and they work just as well, but look different.

You don't need wood to be hard. The finish doesn't stop anything from vibrating, and you don't want a lot of the string's energy to vibrate the body. That's the difference between something like a Les Paul, and a banjo. On a banjo most of the energy from the string goes into vibrating the top, which is a drum head. So you get a loud acoustic output, and then almost zero sustain. On a solid body, you get very little acoustic output, and lots of sustain. The body has enough mass as to not be vibrated much by the strings. A thick poly finish won't change anything, but sometimes they look tacky.

This is just the way I try to think when designing a bass, but if I'm trying to get a warm sound by say using a mahogany body, I need to find a finish that doesn't defeat the purpose. I'd probably try to use an oil or light poly finish. I'm not saying people shouldn't use a resin finish, I just think really high end instruments were designed to take this balance of wood and finish into account.

The finish won't change the tone. I used very hard catalyzed nitro lacquer on some of my basses, and I used oil finish on others. They sound the same. The finish is there to protect the instrument. You get people saying nonsense like the "wood has to breathe"... no, it's dead, it doesn't breathe. Another good one is that moisture will be trapped into the wood. If moisture can escape a finish, it can also enter a finish. So if nitro lacquer really can let moisture pass, it will pass both ways. But all you need to do is spray lacquer on one side of a thin board like a soundboard on a flattop acoustic, to see it will cup, because moisture is getting into the unfinished side.

So all this talk about finish doesn't apply to solid electric guitars. Too much finish on an acoustic is another matter though.

Also, I think the people that are trying to make the accusations that wood doesn't matter, are probably basing their observations on all of the same types of instruments, the typical resin coated guitars with cheap wood somewhere underneath. With that in mind, would most players hear the difference between an alder, ash, or maple body if they were all given the same plastic coating?

Pick up a vintage Fender guitar. Under the lacquer finish is a thick coat of Fullerplast. Fullerplast is a two part resin they used to dip the bodies in. If you have ever tried to refinish one of these guitars, you will see that the stuff is bullet proof. Paint remover won't touch it, and if you really have to get to the wood, you have to sand it off.

No one complains that old Fenders sound bad because of thick poly finish!

What matters is the weight and density of the body wood. But soft light woods like basswood or poplar have a nice warm tone. But they don't look so good.

Same arguments can be had for glue lines. They aren't a problem. Two pieces of wood glued together behave like one piece of wood, such as on the soundboard of an acoustic guitar.

Here are some Fender US made body blanks! I think that's way too many pieces of wood, but that's just from a visual standpoint. They fixed that problem by gluing alder veneer on the front and back. Spray on a sun burst with black sides and no one will be none the wiser.

[David Schwab]

Just a thought, but on a hollow body, especially a jazz box or such, wouldn't the harmonic vibrations of the face alter the distance between the strings and pickups? Yes, minutely, but still, creating a slight Doppler sort of effect? This would most definitely affect the wave shape produced by the pickups.

The top does move a little. Don't know if it has an audible affect though. The other question is if the pickup is moving up and down, is it in or out of phase with the string?

[David King]

I think it's useful to think of the interactions of the vibrating string with the guitar frame and woods in the same way we've come to think about the interactions of an LCR circuit that includes a pickup and a vibrating string as a source. The string-wood circuit obviously has impedance and a resonant frequency. There are certainly corollaries for resistance, capacitance, inductance as well. Hopefully a physicist will tell us what those might be. Both circuits are complex and difficult to analyze accurately as a result. However our ears can tell us a lot if we choose to use them.

[bbsailor]

Bingo.

It's not a matter of wood OR pickups OR finish OR scale OR tailpiece. One needs to think of the entire instrument as a system, and arrange for all the components to work collectively, and in complementary fashion, towards an acoustic/tonal goal.

Mark,

Bingo-Bingo! Add one more thing...the acoustic energy being fed back into the vibrating strings by the amplifier and its settings either directly to the strings or through the body resonating a particular spectrum of energy back into the strings to affect the sustain tonality. Carlos Santana would mark a spot on the stage where he had just the right amount of feedback to achieve his signature sound.

What complicates this issue is the fact that all high impedance pickups have a resonance in the midrange where the ear is the most sensitive. How the body accentuates certain frequencies or sucks energy out of the strings at certain frequencies is highly related to this discussion. However, beyond the pickup resonant point the signal drops at a 12db or higher rate and any upper harmonics are masked and are virtually eliminated from this discussion.


When you examine the evolution of the electric guitar sound, it is tied to what we have been culturally accustomed to hearing either alone or in the mix of being pleasantly combined into the final audio spectrum of popular recorded music. When we analyze the guitar we are separating it from that mix and evaluating it on its own and have built our own language to subjectly label it such as: warm, rich, harsh, piercing, muddy, bright, etc (add your own labels). More importantly, we need to have a technical agreement about what harmonic content relates to each of those labels for any productive discussions to occur. It is interesting to note that on a guitar it is not the fundamental frequency but the harmonics that provide the primary differention between these labels.

Mark hit it right on. Experience in building guitars with various woods, finishes and neck styles allows combinations of things that tend to sound good to be replicated with reasonable expectations. Then I will add, we seek to decompose these variables to attempt to understand how each of the variables fit together with the expectation that with enough knowledge we can manipulate or compliment them to achieve something better, different or marketable.

Could this forum the right place to start doing this?

Joseph Rogowski

[David King]

Would looking at wave forms from a guitar using a scope give us anything useful to compare one guitar to the next?

The characteristics that we use to recognize one instrument from another are more focused on the initial attack than on the decay from what i've read. The only way for the brain to tell the difference between a piano note and say a French horn note it to hear the first few milliseconds, after that their sonic signatures are pretty similar apparently. I wonder if that's really true or if we are just lazy and don't listen well enough. If it is true than it doesn't bode well for there being significant differences between guitars in our perceptions after the initial attack either.

[Bruce Johnson]

Well, the two main tools are:
A Spectrum Analyzer, which gives you a curve of frequency (horizontal) vs amplitude (vertical), at a given instant in time, and
A Scope, which will give you a curve of time (horizontal) vs amplitude (vertical), at a given or averaged frequency.

The best thing is to integrate those two data groups together into a 3-D data map of frequency vs time vs amplitude. That will give you a real picture of the "sound" of an instrument. The point is that, on an instrument, the frequency curve does not stay constant over time. Some frequencies die out faster than others. Likewise, the attack profile isn't the same at all frequencies. That initial Thump will be centered around some part of the frequency curve. So, you have to cross the two measurements against each other to get a real picture of what the instrument is doing.

I haven't messed around with it myself, but I'm assuming that it wouldn't be hard to take a data field like that these days, using these new-fangled computer thingies. You can probably get an App for your IPhone. I'm still sorting out the wiring on my 3-D punch tape machine.....

[David King]

Back in the 1990s you could generate very pretty "waterfall" (3-D) spectrum analyzer plots over time with a then very expensive software package. I have some of those plots of the open strings of a bass I built that someone sent me. I don't think I learned that much from them. I find it difficult to get a consistent attack snapshot, no two plucks are ever exactly alike.
I can see how a waterfall o-scope waveform might be very helpful to see in conjunction with the waterfall spectrum analyzer. That's a lot of integration for the brain to handle too. I think a strobotuner is just as useful as it shows you the defects in realtime while you hear them. Much easier to integrate one visual stream and one auditory stream too. That's what our brains are doing all day anyway.

[David Schwab]

I find it difficult to get a consistent attack snapshot, no two plucks are ever exactly alike.

Bartolini made a picking machine to get around that problem.

[bbsailor]

All,

The following web link provides a technical analysis of the variation in wood and neck types with a variety of pickups.
http://www.calaverasfretworks.com/up...rs_-_Part1.pdf


To see the second part of this article just change ...Part1.pdf to Part2.pdf.

His results indicate that pickup changes account to major changes in tone, but there is a measurable difference with different woods and neck types. This seems to be consistent with many of the comments in this discussion.

Enjoy.

Joseph Rogowski

[ScottA]

Butch is a nice guy, sharp too, we had a booth next to his at SEGAS last year.

I was talking to him a little about this stuff.

He just bought a couple of pickups from us this morning, in fact!

All,

The following web link provides a technical analysis of the variation in wood and neck types with a variety of pickups.
http://www.calaverasfretworks.com/up...rs_-_Part1.pdf


To see the second part of this article just change ...Part1.pdf to Part2.pdf.

His results indicate that pickup changes account to major changes in tone, but there is a measurable difference with different woods and neck types. This seems to be consistent with many of the comments in this discussion.

Enjoy.

Joseph Rogowski

[soundguruman]

Ok, I know this is usually a bad idea to ask on a guitar based forum but, a electric guitar works by a electro magnetic pickup detecting the vibration of magnetically responsive strings and inducing a current in the coils which is sent to the amp to amplify. So in scientific theory: There is no extra effect from wood types, size, dimensions (unless you count length of strings vibrating) etc...

Now, I know this is a bit of a nasty subject with most people but, from my experience there is an acoustic difference in solid body guitars and this is in some small way transfers into the sound when plugged in however, I have never done a straight test using the same strings, same bridge and pickup being swapped out. However, I'm trying to distinguish my what I though (and therefore probably believe) vs what actually happens.

Now, before everyone may get angry with me, the only way I can think that acoustics make a tonal difference in a solid body guitar is microphonics through the electro magnetic pickup. So my question is when potting pickups does it remove all microphonics or is there still a small percentage which can actually be detected and hence, wood types, pick type etc.. may have some effect on a final tonality of the guitar. Can someone explain to me if this is scientifically correct?

Screw science, I'm using DC heaters.

The wood does affect the sound radically. And so does the hardware...
I like the Mahogany / Koa / Ebony kind of sound. Many people like Maple / Alder / Ash type sound...
I can't stand the way bolt-on necks sound. But that is the most popular type...so you can't dismiss it.
But there is a huge difference between them all. No, it's not just the pickups. The wood and construction style play a big part.
Then, there is also a huge variation of pickup sounds also. There is quite a bit to consider in going for a certain sound / tone in a guitar
And, there are so many possibilities to suit so many players... thankfully.

I mean for example, you can change the nut / saddle material from brass to steel to rollers, to bone, to ivory, to fossilized mammoth or walrus ivory, to TUSK artificial ivory, to black water buffalo horn, and to Delrin Nylon, to carbon fiber, to hard cheap plastic...and they all make the guitar sound different. Just changing that "one" thing noticeably alters the tone of the guitar.