Jump to content

Tone, sustain, ect.......?


Dan Furr55

Recommended Posts

  • Members

Dumb question I guess..........

 

                                Why does an acoustic guitar played into a mic and PA sound fuller or richer than a solid body electric guitar played through an amp or PA ?

                                

Link to comment
Share on other sites

  • Members

Mics are supposed to go to a board/pa. That means the levels and in/out impedances are compatible. Unless the board has an input specifically compensated for electric guitar pickups, this will not be the case. The guitar signal will likely suffer high end loss and produce a lifeless, guitarish tone. I don't really get how an output signal can have an impedance but those are the terms. Somebody else will probably explain this more accurately.

Link to comment
Share on other sites

  • Members

From Seymor Duncans website

Piezo Vs. Magnetic Pickups

I am always intrigued in how things developed. How did the guitar develop to what it is today? How do our views change on what constitutes good tone? Those kind of questions keep me occupied during the slow moments of a day, and one day I was asking myself the question: why do we, as electric guitar players, predominantly use sound systems based on electromagnetism and not on piezo-electrics? To answer that question I dove deep in history to see how the two fields, electromagnetism and piezo-electrics, developed to where they are today.

The end of the 19th century is when experimentation began with electricity, as scientists developed some feel on how solid properties behave in some conditions. Various scientists were exploring how magnetic fields, light, electricity, conductivity and many other physical phenomena behaved. The field got a major boost with the equations of Maxwell, which describe all possible behaviors of electromagnetism. His work was to be crucial to the study of physics, mathematics and later even quantum mechanics, and cannot be disconnected from what we as guitar players do on a very basic, scientific level. Electricity isn’t just scientifically monopolized by electromagnetism. Electricity plays a major role in practically every scientific field, for instance pyro-electrics and piezo-electrics.

A simplified explanation on how piezo works.

Pyro-electrics and piezo-electrics are connected in a sense that they are similar but with a different premise: pyro-electrics utilize a heat source on the base material to engage an electrical charge, whereas piezo-electrics use pressure. The first doesn’t really come in handy on a guitar. Maybe Jimi Hendrix would’ve liked a pyro-electric enducer on his guitar during his famed concert on the Isle of Wright, but most of us don’t carry lighter fluid in our back pockets! The latter does come in handy every once in a while. I mention pyro-electrics specifically because that was the get-go of this field of science. The Pierre Curie, the husband of Marie Curie (who became famous for getting two Nobel Prizes, one in physics and one in chemistry and later became infamous for severe radiation poisoning!) conjured a possible link between pyro-electrics and piezo-electrics and indeed, came to a conclusion that they are related.

Electromagnetism uses coils, currents and permanent magnets to create a voltage. There are several mechanisms at work in electromagnetism but it’s sufficient to know that a guitar pickup always has a magnet and a coil. The magnet permeates a permanent magnetic field. The vibrating metal string disturbs that field synchronous with the change of the pitch of the string. This change, in turn, forces the coil to create an induction current, which is also synchronous with the frequency (pitch) of the string. That’s how an electromagnetic pickup works, wether it’s a humbucker, single coil, P-90, dynastic etc etc. They all work by this same basic principle. It’s nothing more but a microphone but instead of a membrane moving with a coil attached to it and the magnetic field staying constant, the magnetic field changes.

A piezo-electric pickup uses pressure to create a current. The current is in close relation with the frequency of the source, of course. The physical reason as to why some materials exhibit this trait is a bit difficult to explain. Simply put, the material has internal charges, positive and negative, and they’re separate from one another. Through deforming the material these charges are released because the symmetry of the unity-cell is disturbed. You could regard it as a capacitor that releases a charge when deformed. This analogy isn’t perfect, but you get an idea on how it works.

A basic schematic for a preamp to work in conjunction with a piezo pickup.

The generated voltage of the piezo-electric system in a guitar is very small. So small that you need a preamp to boost the signal. That on itself isn’t something that would put guitar players off from using a piezo, so what could a reason be? A piezo system is very small and lightweight compared to electromagnetic pickups. Sure, you need a battery, but still. A reason could be that the rate of compression is different with a piezo pickup. Hit the strings twice as hard and a magnetic pickup will give a voltage twice as large. With piezo systems it works exponentially: twice as hard means four times as loud. Twice as soft means four times as weak! That dynamic range would make many players go crazy! I know I would! That’s why the preamps often have a compressor to soften the high and boost the low peaks of the voltage created by the piezo.

The compression is quite audible, too. Maybe a piezo is just too honest and too pure. There is no voicing of the piezo except via the preamp. A magnetic pickup voices the signal directly at the source. The coil geometry, wire gauge, magnet etc etc all tweak and shape the signal that’s being created, allowing you to refine that signal afterwards, but a piezo doesn’t have that capability. Frankly, you’re stuck with what you’ve got. I dare say it’s similar to the discussion of tubes versus solid-state. Tubes ‘sound’ warmer, more natural and organic than solid-state, and maybe that’s also the case with piezo pickups versus electromagnetic pickups.

At the end of the day, the final tonal verdict is all between your ears. Apparently our hearing is more pleased by the warm(er) tones of a copper wire around a magnet than a pulse generated by a compressed crystal when it comes to playing with an amp but we are more inclined in using a piezo in an acoustic guitar due to its pure, clean (dare I say) crystalline tone.

Link to comment
Share on other sites

  • Members

Speaking of Seymour Duncan.........I put a Seymour Duncan in the soundhole of an acoustic once and it sounded damn good. Almost as good as an acoustic

played into a mic. I dont know the science but I feel like a mic picks up the "air" sound of an acoustic or something. Anyway I dont care for piezos too much

but they do give us another sound.

 

To me you have ..........

 

1, Acoustic into a mic...........................wonderful tone

2.Acoustic into mag pickup.................good tone

 3.Acoustic into saddle piezo.................ok tone

4.Hollow body electric with f holes................ok tone but muffled a bit

5. Hollow body with f holes and block of wood...............ok tone , more sustain

6.Solid body electrics...................less tone but not bad

 

I don't know all the science but I feel like its "air", and resonance whatever that is, sustain, harmonics, etc. in varying amounts...........

 

So I have crazy ideas................and crazy questions.......

Like.............

If a hollow body had the f holes closed, and a soundhole cut into it, would it sound like an acoustic?

If an acoustic had the back removed would it lose its resonance and sound like crap?

If a solid body was played into a mic would it sound any different?

If an acoustic was filled with cement would it sound like a solid body?

If I threw my D'angelico into a brick wall what would be the last tone or frequency emitted?

 

Crazy stuff like that..........

 

Dan

 

 

Link to comment
Share on other sites

  • Members
12 minutes ago, Dan Furr55 said:

Speaking of Seymour Duncan.........I put a Seymour Duncan in the soundhole of an acoustic once and it sounded damn good. Almost as good as an acoustic

played into a mike. I dont know the science but I feel like a mic picks up the "air" sound of an acoustic or something. Anyway I dont care fore piezos too much

but they do give us another sound.

 

To me you have ..........

 

1, Acoustic into a mic...........................wonderful tone

2.Acoustic into mag pickup.................good tone

 3.Acoustic into saddle piezo.................ok tone

4.Hollow body electric with f holes................ok tone but muffled a bit

5. Hollow body with f holes and block of wood...............ok tone , more sustain

6.Solid body electrics...................less tone but not bad

 

I done know all the science but I feel like its "air", resonance whatever that is, sustain, harmonics, ect in varying amounts...........

 

So I have crazy ideas................

Like.............

If a hollow body had the f holes closed, and a soundhole cut into it, would it sound like an acoustic?

If an acoustic had the back removed would it lose its resonance and sound like crap?

If a solid body was played into a mic would it sound any different?

If an acoustic was filled with cement would it sound like a solid body?

 

Crazy stuff like that..........

 

Dan

 

 

If a hollow body had the f holes closed, and a soundhole cut into it, would it sound like an acoustic?

Not really. Gretsch did a painted F hole guitar( Country Gentleman) at one time. This was to reduce feedback. This need to be plugged in and use a magnetic pick up anyway.

 

If an acoustic had the back removed would it lose its resonance and sound like crap?

There not a lot of sound that comes from the back of a guitar, but what it does is sets up a resonance box to all the vibrations  will come through the sound hole opening. There is a little bit of sound that is attributed to the back and the sides as well.

 

If a solid body was played into a mic would it sound any different?

There's not much sound that comes from a solid body guitar. 

There's not even much sound that comes from a es 330 hollow body. The resonance box is just to small Now something like a Gibson super 400 or a L5, that's a different story.

If an acoustic was filled with cement would it sound like a solid body?

Remember here you have killed the resonance box of the guitar.

 

I really like semi hollowbody and hollowbody guitars.

I own more than a few. All have pick ups.

Remember before pick ups were installed in guitars they weren't much more than a parlor instrument. They could keep up with wind and brass instruments. Now a violin has a killer resonance box, but only when a bow is used. 

I also have a couple of round neck resonators. They are louder than most acoustics. By the time the dobro was invent, the electric guitar pick up and amp came along shortly after. Whether you had electricity in you house to power it up is a different story.

I can't imagine Robert Johnson filling even a small dance hall with a Gibson L1. Bet he never even went down to the crossroads either.

 

I have been working on open tuning songs these days. Robert Johnson's songs were wither in standard tuning or Open A. Open A puts more tension on the guitar and seems like it has a bit more pop than open G.

Keef is a an open G player. He's become a master at it too.

 

Keef's like one of my fav players.

He just fills in the gaps nicely.

 

 

 

 

Keith: It's not only the high quality of drugs I had that I attribute my survival to. I was very meticulous about how much I took.

'I'd never put more in to get a little higher.

 

I think it was keef that told Brian Jones you're doing too much dope. When Keef says you're doing too much dope, you are really doing too much dope.

 

 

 

 

 

 

 

 

 

 

 

 

 

Link to comment
Share on other sites

  • Members

Thanks Mikeo

 

If Keith Richards says you're doing too much dope.............well that's something to consider!

 

I appreciate all your help........... but one question remains............. just as a curious thought............

If you closed the f holes and cut in a soundhole wouldnt it now sound like an acoustic?

The country gent didn't have a soundhole of any type I dont think.

Another way to ask this............ why do some guitars have f holes away from the strings, and some have round holes right 

under the strings? To me the f holes look nice but are a little muted compared to the round holes........

 

I like hollows and semi hollows too............if theyre not too muddy.........the ones you put here in video were very good.

DO YOU LIKE the center block that some have?

 

Link to comment
Share on other sites

  • Members
2 hours ago, Dan Furr55 said:

Thanks Mikeo

if you closed the f holes and cut in a soundhole wouldnt it now sound like an acoustic?

 

No.  It won't.  The real sound producer of an acoustic guitar is the top.  It is driven much like a speaker.  For that to happen the construction of the guitar has to facilitate the top vibrating; solid top, minimal bracing etc.

Hollow and  semi-hollow electric guitars are usually constructed to minimize the vibration of the top because it causes feedback; laminate tops, center blocks, more bracing. 

Link to comment
Share on other sites

  • Members
1 hour ago, Dan Furr55 said:

Thanks Mikeo

 

If Keith Richards says you're doing too much dope.............well that's something to consider!

 

I appreciate all your help........... but one question remains............. just as a curious thought............

If you closed the f holes and cut in a soundhole wouldnt it now sound like an acoustic?

The country gent didn't have a soundhole of any type I dont think.

Another way to ask this............ why do some guitars have f holes away from the strings, and some have round holes right 

under the strings? To me the f holes look nice but are a little muted compared to the round holes........

 

I like hollows and semi hollows too............if theyre not too muddy.........the ones you put here in video were very good.

DO YOU LIKE the center block that some have?

 

I have a ES 335 and a ES 135 both have a center block. Both have classic 57's in them. The ES 135 has a poplar centerblock and the ES 335 has a maple centerblock.

They will both going into a nice sustaining feedback when pushed through some gain.

Full hollowbodies you need to keep the gain and volume down to control them. 

Rickenbacker semi hollowbodies are made completely different. They are kind of carved out. Amazing guitars, but some folks hate them.

 

 

 

 

 

 

 

Link to comment
Share on other sites

  • Members
12 minutes ago, mrbrown49 said:

No.  It won't.  The real sound producer of an acoustic guitar is the top.  It is driven much like a speaker.  For that to happen the construction of the guitar has to facilitate the top vibrating; solid top, minimal bracing etc.

Hollow and  semi-hollow electric guitars are usually constructed to minimize the vibration of the top because it causes feedback; laminate tops, center blocks, more bracing. 

true.

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...