A fundamental WHY

EveryAxeAGem

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Aug 19, 2014
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If pickups work purely through a magnetic process and not like a acoustic microphone,
1) Why does an electric guitar so strikingly like a guitar, among the zillion possibilities such a 'un-accoustic' transmission process could sound like. It should sound like alien warble or seismic anomalies.
2) Why does a knock on the guitar body (with your knuckles) come out from the amp sounding like....a knock on the guitar body (with your knuckles).
 
If microphones and electric guitar pickups are not that different, then wood would impact the sound of a electric guitar wouldn't it? The electric guitar would be none too different from a semi accostic guitar.

Which is precisely a big part of why wood affects the sound of an electric guitar. But there's more, of course.

Yes, pickups are microphonic.

However, the wood also impacts the vibration of the strings even absent the microphonics, and acts like a resonant filter on a synth. If you think of the strings as oscillators (which they are of course), different woods, different construction methods, etc. will affect how the string-oscillators vibrate. As will the hardware, the anchor points of the hardware on the guitar, and on and on. Because these affect and modulate how the string vibrates, they act as filters, modulators, etc.

Combine these effects of the wood, the design of the guitar, the microphonic nature of the pickups, and about ten zillion other factors, and you have a partial explanation of what's happening. But I submit that the effect of some parts of the guitar are still not well-understood.

Let's face it, if strings and electronics are all that an electric guitar is, we'd expect ones with the same pickups to sound exactly alike regardless of the differences from model to model. The fact is that they do not all sound alike. Not just with PRS, but with any make of guitar.
 
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Microphonics is really astounding, isn't it? I toured Thomas Edison's home and research lab in New Jersey and they played the first recorded band performance that was captured on the precursor to vinyl records: a barrel of wax. It recorded via a needle that quivered to the music via sound capture cone and etched a pattern in the wax as it turned in a spiral. The wax pattern would reproduce the music for subsequent listenings in much the same manner.

With use of a magnetic field, you can achieve sound reproduction through your amplifier, and it's really quite miraculous. Whether your guitar is made out of wood and sounds like a PRS, or is made of meatloaf and sounds like a pile of complete sh!t, your pickups will reproduce the sound you make with it. Why each guitar has the voice it does is the combination of centuries of applied science and observation, and the dice-roll-enigma of what spirit and musicality your trees possessed that sourced your guitar parts. Whether you're sweep picking or beating your axe with your fist, the guitars speak. And that is just badass.
 
Here is a very, very simplified explanation that I give people almost daily at the shop I work in.

You hit the strings. They vibrate, and that vibration is transferred to the body through various points (bridge, nut, etc.). The vibration of the body is then transferred, via those same places, back into the strings. This process repeats until all of that energy is lost and is why every wood, and every guitar really, sounds different. The pickups merely translate those vibrations into an electrical signal.

It's obviously an overly simple explanation, but it is intended to be.

Hope it helps!
 
Keep in mind the reason we have electric guitars: to make a guitar louder. Pickup design was intended to sound like a guitar, just louder. If the intent was to sound like whales humping, we'd all be playing theremins.
 
Just did a very simply experiment. Happy to report. Played a song off an iPhone close to the pickups of an electric guitar, with the phone speaker close but NOT touching the guitar. The song comes out clearly on the amp.

Pickups are accoustically microphonic.

Wonder why there's so much talk out there that they can only detect metal movement, and therefore wood does not matter. This lays all my doubts to rest and can be verified by anyone. Wood does matter and all that high end wood is not just for bling. Don't let anybody tell you otherwise.

You are using this term incorrectly.

(from Wiki) "Microphonics or microphony describes the phenomenon wherein certain components in electronic devices transform mechanical vibrations into an undesired electrical signal (noise). The term comes from analogy with a microphone, which is intentionally designed to convert vibrations to electrical signals."

When a pickup is microphonic, it is because wire in the coils is moving sympathetically to an exterior sound. But pup coils are crappy acoustic transducers. The resulting signal is unwanted noise. Most pups are "potted" with wax to decrease the possibility of these unwanted signals.

In the case of your iPhone or knocking on the guitar body, the pickups are quite deaf to theses sound waves (due to the potting). The strings, however are not. They vibrate sympathetically to the sounds and it is the string movement that gets the pup all hot and bothered enough to produce a signal. The strings are the transducer in this case.

Prove it to yourself. Remove your strings and try the iPhone and the body knock again.
 
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In the case of the iPhone, it's not the strings but the magnetic field that you are affecting.
Please, please, do some research first on how all this works before doing any experiments.

Then again this could be a very good trolling attempt.
 
Different woods don't "give off" different sounds, they subtract (filter) different frequencies from the strings (re. Les' post #4). This isn't shown with one iPhone test BTW.

Then again Mike, you could be right...
 
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