Resonance

[Gitfiddler]

The term RESONANCE comes to mind whenever I pick up and play a Heritage guitar. It does not matter if it is a solid, semi-hollow or full hollow body model. They all just seem to have that magical acoustic thing going on.

 

I thought of this after reading the thread on resonator guitars and later playing my H-530 on the sofa today, listening to the subtle overtones and harmonics it has acoustically. Sure, as a full hollowbody guitar, it is going to have more resonance and volume than one with a tone block or solid wood. But each Heritage, once properly set up, has that something special about it. We've called it 'mojo' and other things, but I like to call it resonance...acoustic resonance to be more specific.

 

Just for fun, I looked up acoustic resonance and found this definition on Wikepedia...

 

"Acoustic resonance is an important consideration for instrument builders, as most acoustic instruments use resonators, such as the strings and body of a violin, the length of tube in a flute, and the shape of a drum membrane. Acoustic resonance is also important for hearing. For example, resonance of a stiff structural element, called the basilar membrane within the cochlea of the inner ear allows hair cells on the membrane to detect sound. (For mammals the membrane by having different resonance on either end so that high frequencies are concentrated on one end and low frequencies on the other.)..."

 

For the truly intellectual folks around here, this portion of the definition is for you:

 

"Resonance of a string

Strings under tension, as in instruments such as lutes, harps, guitars, pianos, violins and so forth, have resonant frequencies directly related to the mass, length, and tension of the string. The wavelength that will create the first resonance on the string is equal to twice the length of the string. Higher resonances correspond to wavelengths that are integer divisions of the fundamental wavelength. The corresponding frequencies are related to the speed v of a wave traveling down the string by the equation

where L is the length of the string (for a string fixed at both ends) and n = 1, 2, 3... The speed of a wave through a string or wire is related to its tension T and the mass per unit length ρ:

So the frequency is related to the properties of the string by the equation

where T is the tension, ρ is the mass per unit length, and m is the total mass.

Higher tension and shorter lengths increase the resonant frequencies. When the string is excited with an impulsive function (a finger pluck or a strike by a hammer), the string vibrates at all the frequencies present in the impulse (an impulsive function theoretically contains 'all' frequencies). Those frequencies that are not one of the resonances are quickly filtered out—they are attenuated—and all that is left is the harmonic vibrations that we hear as a musical note.

String resonance in music instruments

 

Main article: String resonance (music)

String resonance occurs on string instruments. Strings or parts of strings may resonate at their fundamental or overtone frequencies when other strings are sounded. For example, an A string at 440 Hz will cause an E string at 330 Hz to resonate, because they share an overtone of 1320 Hz (3rd overtone of A and 4th overtone of E)."

 

There is more, but for the point of this discussion, the above might be the more scientific definition of the so-called Mojo we all dig in Heritage guitars...or any high quality guitar for that matter.

 

What do you think?

[yoslate]

I think there's no arguing with the science of this. And I think, Tim, that you've introduced this initial empiricism just to get something interesting started. OK, I'll bite, before this regresses into the inevitable long-versus-short- tenon debate. I'd argue that this thesis could be extended to the player of an instrument him or herself. That each of us has an inherent resonance that responds to stimuli. As the string on a given instrument responds to being plucked, we respond to the vibration of the plucked string, amplified, un-amplified, in a way unique to each of us, certain frequencies predominating over (seeming more "pleasing" or resonant than) others. It's like the Martin/Taylor thread. As types, each of those makes of guitar has certain predominating sonic (resonant) characteristics. And within each of those sets are subsets (body styles, scale lengths, combinations of tone woods), which have similar characteristics, unique to the subset, down to the unique characteristics of each individual instrument. Call this reduction subjectivity, if you choose. Here's where the science tends to morph into "mojo." This is where the endless threads on tenons, maple versus rosewood boards, scatter winding, potting, NOS, and 1959 originate. We, our tympanic membranes, our bones, our primary auditory cortices, our hearts all vibrate just a little differently from one another's. We resonate to the resonating stimuli which affect us, and each of us slightly differently. Hence, so many of us tend to "hear" things differently. It's not just the instrument in which an inherent resonance resides.

[Gitfiddler]

Rob~ Only you could respond to such an esoteric topic as 'resonance' in such an eloquent, yet soulful manner!

 

It wasn't my intention to get so deep on the topic, but things just started flowing. I was just so inpired from the tones from all of the Heritage guitars I've played over the years.

 

Once again, I encourage you to put pen to paper (or fingers to PC) and do a little writing in your now retired, post professorial 'free time'.

[Blunote]

I'm not an engineer but spent a few years marketing finite element modeling and analysis tools to engineers. I'm also married to a Noise and Vibration engineer. I like to think some of her brains transfers to me by osmosis.

 

At any rate, when you excite a structure by striking it in some way, it will react dynamically. Many frequencies will resonate, and sort of aggregate as natural frequencies. The structure will react at that frequency and multiples (or harmonics) of it. It's interesting to watch the response of a structure excited at it's natural frequencies. The first introduces bending, the second usually twisting, etc...

 

For instance when you read the specs on a car who's manufacturer brags it's frequency response is 20 hz or 25 hz, I believe that the modes of response will be fewer the highter the number so that the car feels more solid and controlled on the road as it encounters bumpy or washboard roads. or as it deals with other sources of excitation such as engine vibration.

 

Unlike cars, guitars are made of wood. Unlike steel, the structure of wood changes from tree ot tree, and within each board. That variation will always cause guitars to have thier own harmonic response to the vibrations transmitted by strings. No matter how hard a manufacturer tries, every one will be somewhat different.

 

Class dismissed.

[JeffB]

Just an observation from inside the store and kinda off/on topic.

I like how 5 guitar players can agree that a particular guitar is very resonant and then plug it into the same amp and each player makes it sound different with out touching the settings on the amp.

Even though the guitar is resonant its not a universally appealing resonance in the small group.

I've also have noted at other times that from behind a closed door we can tell what amp is being used regardless of what cab its paired with and we could definitely tell if it was a standard strat or LP being played through it but whether it was a good one or a dog of either, none of us would pick.

The other part of the equation, and the biggest part, is we can always pick who is playing without any thought about it and regardless of what guitar they are playing.

After an intensive week of amp and guitar demo's, electric guitar sounds like electric guitar and things like resonance and timbre mean less than they did at the start of the week. The margins become really narrow. It takes a really special amp and guitar combination to stand out for you.

Theres the final factor of being amongst drums and bass and dodgy room acoustics where the most amazingly resonant guitar and luxurious sounding amp means nothing. You end up dialing it in to a narrow beam of sound just to be heard.

But even then through the din of it all you can still pick the player.

[mars_hall]

One thing that I have become acutely aware of in the last year is the difference in sound that comes from using a different pick on the same resonant guitar. Thin picks have a way higher frequency content than stiff ones and there is a huge difference in what comes out. Now I used to swear by thin picks which I pinch at the edge and used to use them to get an bite on the tone. Now I mix it up with Dunlops Ultex .73s and some stiffer picks Marty gave me that I cut down to the size of a dime and drill a few holes for grip sake. Seems to be more articulate and cleaner while still maintaining an edge.

[yoslate]

One thing that I have become acutely aware of in the last year is the difference in sound that comes from using a different pick on the same resonant guitar.

 

Interesting that you should offer this one up, Mark. Katy gave me a big fat pick (Gravity Classic) at PSPIV. Never used anything like it; always the Tortex heavy. Now, I sweat the whereabouts of the Gravity all the time. Love it! And the tone I'm able to produce with it, with all of my guitars, is demonstrably different! Warm and big, with a much softer attack, yet no loss of note definition. Magic with the 535!

[High Flying Bird]

 

Katy gave me a big fat pick (Gravity Classic) at PSPIV. Never used anything like it; always the Tortex heavy. Now, I sweat the whereabouts of the Gravity all the time. Love it!

 

I got one of those too. Later I went out and stocked up on 3mm Dunlop jazz picks and stashed the orange pick Katy gave me in a safe place. I don't think it changes the tone I am getting so much as it seems to increase my accuracy in picking.

 

As for the resonance of a good guitar.... if it doesn't sound good unplugged it wont sound good no matter what. All I have to do is hit the B note on the 1st string at the 7th fret and I can tell if the guitar is dead or alive.

[DetroitBlues]

Can't make heads or tails over the math. I just know what sounds good and what doesn't.... Haven't found a Heritage that doesn't sound good yet...

[Gitfiddler]

 

I got one of those too. Later I went out and stocked up on 3mm Dunlop jazz picks and stashed the orange pick Katy gave me in a safe place. I don't think it changes the tone I am getting so much as it seems to increase my accuracy in picking.

 

As for the resonance of a good guitar.... if it doesn't sound good unplugged it wont sound good no matter what. All I have to do is hit the B note on the 1st string at the 7th fret and I can tell if the guitar is dead or alive.

 

Amen, brother! Nothing like pure and simple Southern logic.

[Guest HRB853370]

The term RESONANCE comes to mind whenever I pick up and play a Heritage guitar. It does not matter if it is a solid, semi-hollow or full hollow body model. They all just seem to have that magical acoustic thing going on.

 

I thought of this after reading the thread on resonator guitars and later playing my H-530 on the sofa today, listening to the subtle overtones and harmonics it has acoustically. Sure, as a full hollowbody guitar, it is going to have more resonance and volume than one with a tone block or solid wood. But each Heritage, once properly set up, has that something special about it. We've called it 'mojo' and other things, but I like to call it resonance...acoustic resonance to be more specific.

 

Just for fun, I looked up acoustic resonance and found this definition on Wikepedia...

 

"Acoustic resonance is an important consideration for instrument builders, as most acoustic instruments use resonators, such as the strings and body of a violin, the length of tube in a flute, and the shape of a drum membrane. Acoustic resonance is also important for hearing. For example, resonance of a stiff structural element, called the basilar membrane within the cochlea of the inner ear allows hair cells on the membrane to detect sound. (For mammals the membrane by having different resonance on either end so that high frequencies are concentrated on one end and low frequencies on the other.)..."

 

For the truly intellectual folks around here, this portion of the definition is for you:

 

"Resonance of a string

Strings under tension, as in instruments such as lutes, harps, guitars, pianos, violins and so forth, have resonant frequencies directly related to the mass, length, and tension of the string. The wavelength that will create the first resonance on the string is equal to twice the length of the string. Higher resonances correspond to wavelengths that are integer divisions of the fundamental wavelength. The corresponding frequencies are related to the speed v of a wave traveling down the string by the equation

where L is the length of the string (for a string fixed at both ends) and n = 1, 2, 3... The speed of a wave through a string or wire is related to its tension T and the mass per unit length ρ:

So the frequency is related to the properties of the string by the equation

where T is the tension, ρ is the mass per unit length, and m is the total mass.

Higher tension and shorter lengths increase the resonant frequencies. When the string is excited with an impulsive function (a finger pluck or a strike by a hammer), the string vibrates at all the frequencies present in the impulse (an impulsive function theoretically contains 'all' frequencies). Those frequencies that are not one of the resonances are quickly filtered out—they are attenuated—and all that is left is the harmonic vibrations that we hear as a musical note.

String resonance in music instruments

 

Main article: String resonance (music)

String resonance occurs on string instruments. Strings or parts of strings may resonate at their fundamental or overtone frequencies when other strings are sounded. For example, an A string at 440 Hz will cause an E string at 330 Hz to resonate, because they share an overtone of 1320 Hz (3rd overtone of A and 4th overtone of E)."

 

There is more, but for the point of this discussion, the above might be the more scientific definition of the so-called Mojo we all dig in Heritage guitars...or any high quality guitar for that matter.

 

What do you think?

 

Of course, as a drummer, for a long time I viewed resonance as how a drum shell interacted with the force of a stick hitting the head. Drums that are tuned to a certain frequency, their resonant frequency, have a longer decay than those that are not. That said, a quality maple or birch drumshell has much more resonance than some of the cheaper woods used in entry level drums.

[yoslate]

 

Of course, as a drummer, for a long time I viewed resonance as how a drum shell interacted with the force of a stick hitting the head. Drums that are tuned to a certain frequency, their resonant frequency, have a longer decay than those that are not. That said, a quality maple or birch drumshell has much more resonance than some of the cheaper woods used in entry level drums.

 

And I wish more drummers had an awareness of this sort of thing, Will. Love a drummer who understands the concept of actually tuning his drums, particularly in the studio!

[RhoadsScholar]

I think Nigel says it best.

 

http://www.youtube.com/watch?v=XutwkruACsA&feature=player_embedded