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Directional high pitch sound.


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I was wondering if cutting some fretwork on the sides of the endcaps near the high notes of the right hand side of duets would help balance the sound. It is a common (if not tired) topic of discussion that the bass notes (especially when played several at once) have a tendency to overpower the higher notes.

 

In this interview Brian Hayden (the inventor of the Hayden duet system) discusses how to play the instrument in response to this phenomenon:

 

Interview with Brian Hayden

"...You play the treble notes more or less joined up together, with tiny little spaces between them, and you play the bass notes about half of what the note indicates on the music.

That's what I would always do for any sort of folk thing. You'd be playing a tune, where tune is played continuously but with tiny little gaps, and the bass is played like 'Um, rest, Pah, rest. Um, rest, Pah, rest.' ..and keeping it very light. ..."

 

Here are a few references on the diffraction of sound. I'm not sure if this really applies to the frequency range of a concertina, but it sure seems so:

 

http://hyperphysics.phy-astr.gsu.edu/HBASE...nd/diffrac.html

"The fact that diffraction is more pronounced with longer wavelengths implies that you can hear low frequencies around obstacles better than high frequencies, as illustrated by the example of a marching band on the street."

 

http://physics.suite101.com/article.cfm/diffraction_of_sound

higher frequency sounds can be heard more clearly if the listener is directly in front of the source, while lower frequencies can be heard quite clearly from a wide range of angles.

 

http://www.glenbrook.k12.il.us/gbssci/phys...und/u11l3d.html

Diffraction of sound waves is commonly observed; we notice sound diffracting around corners or through door openings, allowing us to hear others who are speaking to us from adjacent rooms. Many forest-dwelling birds take advantage of the diffractive ability of long-wavelength sound waves. Owls for instance are able to communicate across long distances due to the fact that their long-wavelength hoots are able to diffract around forest trees and carry farther than the short-wavelength tweets of song birds. Low-pitched (long wavelength) sounds always carry further than high pitched (short wavelength) sounds.

 

So, it seems that the bass notes naturally radiate out in all directions while the high notes go shooting straight out the ends. If you let some of that high pitch sound go toward the audience and the player then you'd get a more balanced sound.

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Other Jim (:)), are you speaking in terms of designing a new box with more open fretwork (or more openings) near the high reeds, or are you considering modifying an existing instrument?

 

I would personally be loathe to do the second.

 

Note that in higher-quality Englishes and duets, it was common (though not universal) to have the fretwork more open over the higher reeds than over the lower. That's true of all four instruments in this photo (in the English System Concertina - Buyer's Guide here on concertina.net), though not all to the same degree. My 80-button Maccann (sorry, no photos to hand) has significantly less open fretwork in the lower range than in the higher of each hand, and it also has considerably less open fretwork in the left hand than in the right. (The lowest note in the right hand is 1½ octaves higher than the lowest note in the left. The highest note in the right hand is 2 octaves higher than the highest in the left.) On those few instruments I'm aware of with openings around the sides of the ends, I think they all have these openings around all 6 sides, none just at the higher "end".

 

A separate issue is the articles about diffraction. I don't believe they apply. Diffraction around objects in a room might mean that sitting behind a pillar (or a large head?) will attenuate the treble more than a truly deep bass, but it depends on the scale of the obstruction relative to the wavelength of the sound, and I don't know how much difference there would be between G below middle C and a note 3 octaves higher for a pillar half the width of a person. But if the obstacle that the sound must pass is not one or a few objects -- a small fraction of the possible directions the sound could travel, -- but a solid wall with holes in it (does that sound like a description of fretwork?), it can attenuate frequencies of wavelength much longer than the size of the holes (i.e., the bass) much more than higher frequencies. It is this effect which makes possible blocking radio transmissions with a screen of metallic wire mesh, rather than needing a solid wall of metal.

 

A complicating factor is that I'm pretty sure the some amount of sound -- I'm not at all sure how much -- is transmitted through the wood and radiated from the end itself, not just through the holes in the fretwork.

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Other Jim (:)), are you speaking in terms of designing a new box with more open fretwork (or more openings) near the high reeds, or are you considering modifying an existing instrument?

 

I would personally be loathe to do the second.

The former. Jim , I and another person have orders pending with Bob Tedrow for Hayden duets, and are considering asking him for some innovative features, including sound holes in the sides of the ends, facing the player and/or the audience.

 

No, we wouldn't take our power drills to a WHeatstone or a Lachenal :blink: So far I've held off drilling an extra handrest hole in my Elise!

 

We're also discussing among ourselves the standard Hayden tilt or slant angle of the handrest relative to the button rows, whether the 10.5 degrees is optimum, and whether we want adjustable, moveable handrests.

Note that in higher-quality Englishes and duets, it was common (though not universal) to have the fretwork more open over the higher reeds than over the lower. That's true of all four instruments in this photo (in the English System Concertina - Buyer's Guide here on concertina.net), though not all to the same degree. My 80-button Maccann (sorry, no photos to hand) has significantly less open fretwork in the lower range than in the higher of each hand, and it also has considerably less open fretwork in the left hand than in the right. (The lowest note in the right hand is 1½ octaves higher than the lowest note in the left. The highest note in the right hand is 2 octaves higher than the highest in the left.) On those few instruments I'm aware of with openings around the sides of the ends, I think they all have these openings around all 6 sides, none just at the higher "end".

THis is really great to hear. It means that concertina makers have already addressed the issue of tonal balance across the scale, and done what we were thinking of asking Bob to do. At least have less open fretwork on the left side.

 

Say, how long would it take you to grab a digital camera and shoot up that 80-key Maccann?

A complicating factor is that I'm pretty sure the some amount of sound -- I'm not at all sure how much -- is transmitted through the wood and radiated from the end itself, not just through the holes in the fretwork.

This probably affects the low and mid-range frequencies more than the highest pitches. Open fretwork will discriminate in favor of the high pitches -- good.

--Mike K.

Edited by ragtimer
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Say, how long would it take you to grab a digital camera and shoot up that 80-key Maccann?

Gonna be moving about. Will try to remember to do it when I'm near the instrument, but I don't know how soon after that I'll have an internet connection.

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Say, how long would it take you to grab a digital camera and shoot up that 80-key Maccann?

Gonna be moving about. Will try to remember to do it when I'm near the instrument, but I don't know how soon after that I'll have an internet connection.

 

Don't forget to get a copy onto the MacCann ning site !

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Bob Tedrow has some examples of side-vented instruments:

 

http://hmi.homewood.net/fretless/

Thanks, Jim. I would suggest, for a Duet, that there still be some normal fretwork aroudn the buttons (but less than usual on the RH side), and that side vents not be in all 6 or 8 flats, but only in those facing up at hte player's face and those facing the audience. Tho no real harm in having vents all the way round.

 

Also maybe no side vents on the LH side -- or if so, then hardly any fretwork.

--Mike K.

Edited by ragtimer
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Would it be an idea to have extra fretwork openings on both sides and then experiment with different arragements of baffles to see what effect they have?

 

That way you end up with a more symetrical looking instrument that you may even be able to alter the sound quality on for different occasions.

 

Robin Madge

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Would it be an idea to have extra fretwork openings on both sides and then experiment with different arragements of baffles to see what effect they have?

 

That way you end up with a more symetrical looking instrument that you may even be able to alter the sound quality on for different occasions.

 

Robin Madge

Symmetrical? Gee, we like the ends ot lookd ifferent to save those embarrassing moments when you picj up the instrument backwards :P

 

Seriously, thanks for the suggestion. We've beeen toying with ideas for sliding vanes to open or close sound vents. These could be used to adjust balance (LH versus RH, high notes versus low) or to tone down the whole thing for practicing indoors.

 

There's an old technology called "jalousie" using large sliding panels -- kind of like a swell box on a pipe organ.

--Mike K.

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A separate issue is the articles about diffraction. I don't believe they apply.

http://physics.suite101.com/article.cfm/diffraction_of_sound

"higher frequency sounds can be heard more clearly if the listener is directly in front of the source, while lower frequencies can be heard quite clearly from a wide range of angles."

 

But this reference seems to indicate that it does apply. The higher frequencies are channeled out the ends of the instrument. From there, if this does apply, they stay on a relatively narrow beam. It is a possibility that the higher frequencies are already so channeled that opening side frets wouldn't make much difference. On the other hand it couldn't hurt.

 

Note that in higher-quality Englishes and duets, it was common (though not universal) to have the fretwork more open over the higher reeds than over the lower.

Ah ah! Although I don't think I want to muffle the bass notes at all. I just want to set the higher notes free, to turn them up to Volume 11 so to speak.

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A separate issue is the articles about diffraction. I don't believe they apply.

http://physics.suite101.com/article.cfm/diffraction_of_sound

"higher frequency sounds can be heard more clearly if the listener is directly in front of the source, while lower frequencies can be heard quite clearly from a wide range of angles."

 

But this reference seems to indicate that it does apply. The higher frequencies are channeled out the ends of the instrument. From there, if this does apply, they stay on a relatively narrow beam. It is a possibility that the higher frequencies are already so channeled that opening side frets wouldn't make much difference. On the other hand it couldn't hurt.

 

Note that in higher-quality Englishes and duets, it was common (though not universal) to have the fretwork more open over the higher reeds than over the lower.

Ah ah! Although I don't think I want to muffle the bass notes at all. I just want to set the higher notes free, to turn them up to Volume 11 so to speak.

 

The opening topic refers to the tendency of 'lower notes to overpower higher notes'. I get the impression that lower pitched reeds require significantly less air pressure than higher pitched reeds to vibrate and in the process the lower pitched reeds are able to jump in first and steal more than their fair share of air pressure from the higher pitched reeds. There are subtle ways of playing in which this problem can be overcome, or well hidden, but I cannot see how increasing or decreasing apertures in the fretwork is likely to make a great deal of difference.

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The opening topic refers to the tendency of 'lower notes to overpower higher notes'. I get the impression that lower pitched reeds require significantly less air pressure than higher pitched reeds to vibrate and in the process the lower pitched reeds are able to jump in first and steal more than their fair share of air pressure from the higher pitched reeds. There are subtle ways of playing in which this problem can be overcome, or well hidden, but I cannot see how increasing or decreasing apertures in the fretwork is likely to make a great deal of difference.

 

The lower pitched reeds are slower to speak, but once up and going take a lot more air than higher pitched reeds. This article by Wim Wakker is informative on this subject:

 

http://www.concertinaconnection.com/concertina%20reeds.htm

"...In general, larger reeds need more time to get up to maximum amplitude than smaller reeds. ..."

 

At the end of that article is a section that is very pertinent to this discussion:

 

"The last part of the journey of the sound waves in the instrument is the action space. Basically there are two objectives possible.

 

The first one is to try to produce as much of the harmonics that are left. Because sound reflection diminishes the higher frequencies, there should be as little reflection as possible. In this case the fretwork will be very open. If the goal is to amplify the higher harmonics, which produces a very bright sound, metal ends are used. These ends reflect the sound waves better than other materials because of the hard and smooth surface. The openness of the fretwork determines how much the waves will reflect before leaving the instrument.

 

In most metal ended concertinas the fretwork is adjusted to the specific frequency of the tone. The lower notes need more reflection, which produces a somewhat warmer sound, than the high notes. If you look at the top models with metal ends, you’ll see that they adjusted the fretwork to the specific frequencies.

 

The other objective can be to produce a round warm tone, filtering more high frequencies. This is done by increasing the sound reflection with wooden ends with little fretwork. Wood is perfect for absorbing the higher frequencies and amplifying lower ones. The openness of the fretwork decides again how long the waves will be kept in the action space.

 

In the 19th century it was custom to install baffles, to filter the high frequencies. This was done in two different ways. In early instruments they used spruce wooden baffles to amplify the lower and middle frequencies rather than cutting the high ones. These instruments usually had German silver or brass reeds, which produce very little high frequencies. Later, when steel reeds became standard, which produce more higher frequencies, they used leather baffles which do not amplify any frequencies, but only cut the higher ones.

 

The type of wood used for the ends plays only a small role it the sound quality of a concertina. The sound produced by the vibration of the ends is nihil compared to the sound reflection they cause. There is a difference between instruments with hard and soft wooden ends, but again, it is the absorbing effect that causes the difference, not the vibrating of the ends."

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The opening topic refers to the tendency of 'lower notes to overpower higher notes'. I get the impression that lower pitched reeds require significantly less air pressure than higher pitched reeds to vibrate and in the process the lower pitched reeds are able to jump in first and steal more than their fair share of air pressure from the higher pitched reeds. There are subtle ways of playing in which this problem can be overcome, or well hidden, but I cannot see how increasing or decreasing apertures in the fretwork is likely to make a great deal of difference.

 

The lower pitched reeds are slower to speak, but once up and going take a lot more air than higher pitched reeds. This article by Wim Wakker is informative on this subject:

 

http://www.concertinaconnection.com/concertina%20reeds.htm

"...In general, larger reeds need more time to get up to maximum amplitude than smaller reeds. ..."

 

At the end of that article is a section that is very pertinent to this discussion:

 

"The last part of the journey of the sound waves in the instrument is the action space. Basically there are two objectives possible.

 

The first one is to try to produce as much of the harmonics that are left. Because sound reflection diminishes the higher frequencies, there should be as little reflection as possible. In this case the fretwork will be very open. If the goal is to amplify the higher harmonics, which produces a very bright sound, metal ends are used. These ends reflect the sound waves better than other materials because of the hard and smooth surface. The openness of the fretwork determines how much the waves will reflect before leaving the instrument.

 

In most metal ended concertinas the fretwork is adjusted to the specific frequency of the tone. The lower notes need more reflection, which produces a somewhat warmer sound, than the high notes. If you look at the top models with metal ends, you’ll see that they adjusted the fretwork to the specific frequencies.

 

The other objective can be to produce a round warm tone, filtering more high frequencies. This is done by increasing the sound reflection with wooden ends with little fretwork. Wood is perfect for absorbing the higher frequencies and amplifying lower ones. The openness of the fretwork decides again how long the waves will be kept in the action space.

 

In the 19th century it was custom to install baffles, to filter the high frequencies. This was done in two different ways. In early instruments they used spruce wooden baffles to amplify the lower and middle frequencies rather than cutting the high ones. These instruments usually had German silver or brass reeds, which produce very little high frequencies. Later, when steel reeds became standard, which produce more higher frequencies, they used leather baffles which do not amplify any frequencies, but only cut the higher ones.

 

The type of wood used for the ends plays only a small role it the sound quality of a concertina. The sound produced by the vibration of the ends is nihil compared to the sound reflection they cause. There is a difference between instruments with hard and soft wooden ends, but again, it is the absorbing effect that causes the difference, not the vibrating of the ends."

 

Thanks Jim. Fascinating stuff in so far as I fully understand it. There are probably endless ways in which the ultimate overall tone of an instrument can be affected and adjusted but ultimately you have to settle for what you've got and exploit all it's possibilities to the full.

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The opening topic refers to the tendency of 'lower notes to overpower higher notes'.

 

I must admit that I have not observed this tendency, either with my Lachnal Crane or my Stagi Anglo. I did notice it when I tried out a Rochelle, on which the high LH notes got drowned out by the low LH notes. But even here, the LH did not seem to generally drown the RH.

 

There are subtle ways of playing in which this problem can be overcome, or well hidden, but I cannot see how increasing or decreasing apertures in the fretwork is likely to make a great deal of difference.

I wonder whether the way you hold the instrument could be one of these "subtleties" that make a difference. I play both Anglo and Duet with the LH end propped on my knee, so it's the RH side that is moving to create the air pressure. Could it be that the side that dynamically influences the pressure gets the pressure slightly earlier than the stationary side? That the "pressure wave" takes a split second to reach the other end of the bellows?

 

Just a thought!

 

Cheers,

John

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The opening topic refers to the tendency of 'lower notes to overpower higher notes'.

 

I must admit that I have not observed this tendency, either with my Lachnal Crane or my Stagi Anglo. I did notice it when I tried out a Rochelle, on which the high LH notes got drowned out by the low LH notes. But even here, the LH did not seem to generally drown the RH.

 

There are subtle ways of playing in which this problem can be overcome, or well hidden, but I cannot see how increasing or decreasing apertures in the fretwork is likely to make a great deal of difference.

I wonder whether the way you hold the instrument could be one of these "subtleties" that make a difference. I play both Anglo and Duet with the LH end propped on my knee, so it's the RH side that is moving to create the air pressure. Could it be that the side that dynamically influences the pressure gets the pressure slightly earlier than the stationary side? That the "pressure wave" takes a split second to reach the other end of the bellows?

 

Just a thought!

 

Cheers,

John

 

John, I suppose that one subtlety is to allow a tiny split second for a high note to speak before its accompanyimg chord is permitted to join in and (possibly) rob it of initial air pressure. The 'subtlety' coming from ensuring that the split second is to all intents and purposes undetectable. Less of a problem, I would think, to those who play at high volume but of greater significance to those of us who choose to play in a more delicate pianissimo style. And no problem whatsoever to those who might play an instrument that does not have this characteristic in the first place. Just another thought ! Over and out, Rod

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  • 3 weeks later...

I recently tried this experiment: flip the instrument around and play the melody in the low notes, using the right hand, and the backup in the high notes, using the left hand.

 

(This is a cool feature of the Hayden. The button layout is the same, even reversed. Although "the slant" of the official standard points toward the handle rather than away from the handle --when playing reversed. Which I think makes the buttons much more accessible especially on long bellows pulls, but that's another story.)

 

According to the theory I referred to in my original post, the strong low melody line should have overpowered the wispy little high notes trying to play backup. Just the opposite was the case! High notes when playing backup on the left hand TOTALLY OVERPOWER the low notes played on the right hand!!! So this calls into question the whole idea that the low notes, by virtue of being more diffuse, are physically going to always overpower higher notes.

 

So maybe at these frequencies and this type of directionality these physical diffraction laws don't apply? If this is the case then "backup" itself has a tendency to overpower, unless deftly adjusted by the player. And if extra fretwork is cut into the right side then when reversed (and I understand there are players who wish to do a lot of that) the left(high) notes would overpower even more.

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  • 2 weeks later...
According to the theory I referred to in my original post, the strong low melody line should have overpowered the wispy little high notes trying to play backup. Just the opposite was the case! High notes when playing backup on the left hand TOTALLY OVERPOWER the low notes played on the right hand!!! So this calls into question the whole idea that the low notes, by virtue of being more diffuse, are physically going to always overpower higher notes.

 

So the problem is nothing to do with low notes v high notes but comes from the playing style? Which is in effect what Brian Heydon is saying in the quote in the original post.

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According to the theory I referred to in my original post, the strong low melody line should have overpowered the wispy little high notes trying to play backup. Just the opposite was the case! High notes when playing backup on the left hand TOTALLY OVERPOWER the low notes played on the right hand!!! So this calls into question the whole idea that the low notes, by virtue of being more diffuse, are physically going to always overpower higher notes.

 

So the problem is nothing to do with low notes v high notes but comes from the playing style? Which is in effect what Brian Heydon is saying in the quote in the original post.

That is very interesting finding. It may be re-inventing of the wheel, but ones in a while it has to be done. Hmm.

It's application to duets (and Anglo is a version of it) is straight forward. Just don't hold those left side buttons depressed too long.

But what to do with the English system?

If you play some written pieces, sometimes a "melody" is played against a long "bass" note. Re-arranging? Proves that English was not created for amateurs, doesn't it?

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