dark & thick sound = poor projection

Construction and repair of Classical Guitar and related instruments
Stephen Faulk
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Re: dark & thick sound = poor projection

Post by Stephen Faulk » Mon Apr 02, 2018 12:01 am

That would be great, I'm very interested in the relationship between the cross di-pole and the Nile Scene from Aida...
Patience at the bending iron pays in rounded dividends!

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prawnheed
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Re: dark & thick sound = poor projection

Post by prawnheed » Mon Apr 02, 2018 12:49 am

Lower frequencies will be attenuated less than higher frequencies when passing through things which absorb sound. The concept is well understood by howler monkeys in the South American forests and by the pygmy tribes in the Central African forests who use their boomimg voices and huge drums respectively to communicate over long distances with interveneing trees. Also global systems to communicate with submarines rely on this.

A guitar needs to transmit through a forest of people dressed in their finest. The ones at the back are only going to hear the bottom end of the performance and if the guitar is lacking in the high end, they're not going to hear any of that bit. And as we hear frequencies which fall in the fairly narrow vocal range much better than we do frequencies which lie outside of that range, they will not hear much at all. That's why those seats are cheaper.
Last edited by prawnheed on Mon Apr 02, 2018 12:51 am, edited 1 time in total.

Stephen Faulk
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Re: dark & thick sound = poor projection

Post by Stephen Faulk » Mon Apr 02, 2018 1:17 am

The peoples in Africa such as the Twa and Bantu also use a high frequency style of overtone singing that carry in distance. But we are talking about a context of a range of a few city blocks and smaller. In the context of a guitar concert the lows that are supported by overtones project or carry better than those which have the high partials fall out.

If a carpenter is building a house and hitting a big nail into some dry wood and uses the sweet spot of the hammer it will create a high frequency *ping* sound that will be heard father away than the lower frequency that might move more air or be palpable in impact on the body at closer range, The hammer hitting the sweet spot will be carried a few blocks, but the lows will drop out. Finding the sweet spot in the way the guitar string drives the top is closer to the hammer nail sweet spot model. The guitar has to have the high partial support, the PING, in order for it to cut through to the back - as it was brought up earlier that is the reason why some guitars need 20 feet of space before the sound sorts itself out and some of the lows drop away.

If singers facing rooms full of meat puppets try to project through the meat with low end push it does not work. It can get loud to push with unsuppported gusto, but resonance of the skull and air column in the body produce the *cut* to project, and a singer tunes that resonance to support the his or her range with high partial support in the proper amount. That's the hammer hitting the nail in the sweet spot and the framing of a building is a giant skull. And there's some relation to that and the sweet spot of a guitar, the finger is the hammer and the string drives the top. If all is set up right the high partials support the sound and push it through the meat bodies.
Patience at the bending iron pays in rounded dividends!

simonm
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Re: dark & thick sound = poor projection

Post by simonm » Mon Apr 02, 2018 7:57 am

One of the early posts in the thread mentioned somewhat thicker tops having more projection with the example of Hauser style guitars. As I understand it later Romanillos guitars have gotten slightly thicker tops. Do later Romanillos guitars project more than the earlier instruments? Given that he was strongly influenced by Bream's Hauser guitars, I suppose the difference over time might not be much anyway. Anyone got personal experience of this?

Alan Carruth
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Re: dark & thick sound = poor projection

Post by Alan Carruth » Mon Apr 02, 2018 5:40 pm

Lower pitches tone may 'carry' better over long distances when measured by dB meters. We're measuring with ears. In general, 'normal' human hearing is most sensitive in the range between 2Khz-4kHz. In general, it takes about a hundred times as much power in the air to produce an audible sound at the fundamental of the lowest note of the guitar as it does at 3kHz. Keeping in mind that the guitar is too small to radiate sound efficiently at that low pitch, and becomes much more efficient as you go up, it's not surprising that it's usually more effective to increase 'projection' by improving the high-end function than the low. Elephants communicate for miles using sounds in the 10-20 Hz range, iirc. They've got big enough ears to hear them...

chiral3
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Re: dark & thick sound = poor projection

Post by chiral3 » Mon Apr 02, 2018 6:17 pm

I think the other variable that needs to be combined with those statements is that while lower pitches "carry" better, direction is lost. I seem to recall that sirens have to be in a certain frequency band because people can deduce where they are coming from better. I believe this is related to the dispersion per my earlier comments.
"Life is under no obligation to give us what we expect" - Margaret Mitchell

Stephen Faulk
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Re: dark & thick sound = poor projection

Post by Stephen Faulk » Tue Apr 03, 2018 1:26 am

I've been reading about how cicada produce sound, it's very interesting, and as far as I can tell so far, the projecting potency of cicada clicking is made possible by the allowing of high frequency to mix together or work together. The cicada produce two frequencies at once one on either side of the body using an organ called timbal, the two sounds somehow boost each other together.

I'll find the article later and post it. It's interesting from a mechanical point-

Here: http://www.sciencemag.org/news/2013/06/ ... adas-chirp

From the article:

" Instead of acting like a single speaker, the cicada's left and right tymbals may act like two speakers that produce sound waves that constructively combine. To see how that happens, imagine two waves traveling on the same string. Where the peaks of the two waves perfectly overlap, they add together and spike much higher than the peak of either wave alone. If the waves are sound waves traveling through the air, the peaks would be spots where the volume is very high. The cicadas may be artfully using this effect to pump their volume to deafening levels without expending as much energy as if a single tymbal had to do it alone."
Patience at the bending iron pays in rounded dividends!

ChristianSchwengeler
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Re: dark & thick sound = poor projection

Post by ChristianSchwengeler » Tue Apr 03, 2018 9:00 pm

Nice thread :D

DennisTolz
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Re: dark & thick sound = poor projection

Post by DennisTolz » Mon Apr 09, 2018 6:13 pm

Alan Carruth wrote:
Sun Apr 01, 2018 7:44 pm
The cross dipole helps in several ways, but there is more to it than that, for sure. I pay a lot of attention to the spectrum between, say, 600-1000 Hz, the lower part of the 'resonance continuum', where it seems as though the number of peaks and the peak-to-dip ratio matters in the timbre. There's an old study by Mathews and Kohut on this. If I can find it I'll post a pointer.
Interesting thread! Alan, I wasn't able to find the study you are referring to, any chance you can point me in the right direction? A link would be much appreciated. Thank you!

ChristianSchwengeler
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Re: dark & thick sound = poor projection

Post by ChristianSchwengeler » Mon Apr 16, 2018 7:17 pm

The question is if we really need all this "projection" and volume and my experience is that most people play in smaller rooms normally and a fuller, darker sounding instrument can have its vantage also in terms of sound quality.

I have built quit a few difrent models over the years and started to build DT's a few years ago, they have really more fundamentals in my case - the trebles are good and with nice timbre, but not so bright like in other concepts.

I assisted to a guitar festival a few month ago and they used a very advanced amplification system, a kind of a box in front of the player like a somewhat bigger musicstand. The amplification was so good and natural that you could impossibly know that it was amplificated. I guess in the future a lot of player will use this kind of system and the normally rather poor projecton of CG will be out of the dicussion and we can focus again on sound quality alone.

DennisTolz
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Re: dark & thick sound = poor projection

Post by DennisTolz » Sun May 13, 2018 9:07 am

ChristianSchwengeler wrote:
Mon Apr 16, 2018 7:17 pm
I assisted to a guitar festival a few month ago and they used a very advanced amplification system, a kind of a box in front of the player like a somewhat bigger musicstand. The amplification was so good and natural that you could impossibly know that it was amplificated. I guess in the future a lot of player will use this kind of system and the normally rather poor projecton of CG will be out of the dicussion and we can focus again on sound quality alone.
Christian, I absolutely agree with you. I think the unamplified classical guitar will never be loud enough to play with lets say a string quartet. Therefor it doesn't make much sense to me if luthiers solely focus on the volume of their instruments and disregard its sound quality. That said, I do understand that a certain level in volume is desirable and necessary.
I wonder do you know, what kind of system was used to amplify at the festival you are talking about?

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Arash Ahmadi
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Re: dark & thick sound = poor projection

Post by Arash Ahmadi » Sun May 13, 2018 9:24 am

Well, this might be because the brighter sound travels further and is more distinctive. Spruce top guitars may be a good example. Cedar top guitars may have more depth but the sound can't travel very far compared to the spruce top. An exaggerated example can be the comparison of a Soprano singer and a bass singer.

But the fact that a guitar is loud in a room but isn't on stage does not make any sense.
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

ChristianSchwengeler
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Re: dark & thick sound = poor projection

Post by ChristianSchwengeler » Sun May 13, 2018 6:20 pm

DennisTolz wrote:
Sun May 13, 2018 9:07 am
ChristianSchwengeler wrote:
Mon Apr 16, 2018 7:17 pm
I assisted to a guitar festival a few month ago and they used a very advanced amplification system, a kind of a box in front of the player like a somewhat bigger musicstand. The amplification was so good and natural that you could impossibly know that it was amplificated. I guess in the future a lot of player will use this kind of system and the normally rather poor projecton of CG will be out of the dicussion and we can focus again on sound quality alone.
Christian, I absolutely agree with you. I think the unamplified classical guitar will never be loud enough to play with lets say a string quartet. Therefor it doesn't make much sense to me if luthiers solely focus on the volume of their instruments and disregard its sound quality. That said, I do understand that a certain level in volume is desirable and necessary.
I wonder do you know, what kind of system was used to amplify at the festival you are talking about?
I don't know what brand it is, but it is very sofisticated. Sound is capted with top level mics which costs a few thousend each and the speaker system is top also. This is how it looks:
amp 1.jpg
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