Changing The Sound Of A Concertina

[David Levine]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

 

The Herrington, which I didnt think had an especially pleasing sound (although it is well made), doesn't have reed chambers. Do other hybrids likewise have no proper reed chambers? Could this account for a larger difference in sound than just the difference in reed design? Which hybrids do or don't have individual reed chambers?

 

Is it then possible to "fine tune" a concertina by altering the reed chambers to bring each note into greater balance with the whole - such as dampening the shrill notes at the top of the octave?

 

 

 

Sorry for the garbled topic title. I wish it was possible for me to edit that as well as the text. Can that be done?

Edited June 27, 2008 by cocusflute

[Rod]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

 

The Herrington, which I didnt think had an especially pleasing sound (although it is well made), doesn't have reed chambers. Do other hybrids likewise have no proper reed chambers? Could this account for a larger difference in sound than just the difference in reed design? Which hybrids do or don't have individual reed chambers?

 

Is it then possible to "fine tune" a concertina by altering the reed chambers to bring each note into greater balance with the whole - such as dampening the shrill notes at the top of the octave?

 

Am I to assume that the fabric backing behind my instruments fretted metal ends is purely to filter dust and other foreign bodies from entering the inner mechanism and that it has no effect whatsoever on the overall tone emitted from the instrument. I'm not prepared to experiment with my own instrument as I am perfectly happy with it's existing tonal balance. But if I were to drape a piece of the same fabric across my ears I would not be altogether surprised if it were to have the effect of possibly softening any 'shrillness'.... if it existed. I guess that different fabrics might exhibit different properties. ?? Obviously the fabric must not restrict the bellows ability to breath freely. The combinations could be endless ?

[Richard Morse]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

I would think so though the effect may be nil to minor depending on your instrument. Most hybrid makers have all wood chamber parts while traditional concertinas use the bellows frame gasket chamois for that part of the chamber enclosure. I would think that the addition of leather surfacing or alteration to rougher surfaces would have far less sound dampening effect on a vintage concertina than on a hybrid.

It's interesting that the Herrington... doesn't have reed chambers. Do other hybrids likewise have no proper reed chambers?

HH's concertinas *do* have reed chambers, as do all other hybrids. They are constructed differently, and might appear to be quite different from traditional concertinas, but they are there.

 

-- Rich --

[Richard Morse]

Am I to assume that the fabric backing behind my instruments fretted metal ends is purely to filter dust and other foreign bodies from entering the inner mechanism and that it has no effect whatsoever on the overall tone emitted from the instrument.

Most concertinas have no fabric fret coverings at all. I don't think that dust/hair/lint/etc. is a problem as foreign bodies entering the box rarely happens or causes problems. In fact I don't think it's happened once in the 20+ years I've had my Wheatstone. But I *do* note that stuff does occasionally impede reeds from responding well, and that "stuff" nearly always originates from the making of the instrument (sawdust, flocking, chips) with the lesser the quality of the instrument the more problems of this nature. So in effect that fabric is keeping the stuff IN.

 

So why have fabric? Most likely for appearance, and vestigial of accordion-making.

 

There *can* be a tonal effect depending on the qualities of the fabric with the more closed/thicker/texturous fabric having the more effect. Keep in mind that this effect can be noticeable/pronounced even if you don't cover the fretwork holes. There is a lot more surface area inside the ends behind the fretwork, under the buttons, sides of the ends and surface of the action board (disc) and padpan which could be lined.

 

-- Rich --

[Rod]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

I would think so though the effect may be nil to minor depending on your instrument. Most hybrid makers have all wood chamber parts while traditional concertinas use the bellows frame gasket chamois for that part of the chamber enclosure. I would think that the addition of leather surfacing or alteration to rougher surfaces would have far less sound dampening effect on a vintage concertina than on a hybrid.

It's interesting that the Herrington... doesn't have reed chambers. Do other hybrids likewise have no proper reed chambers?

HH's concertinas *do* have reed chambers, as do all other hybrids. They are constructed differently, and might appear to be quite different from traditional concertinas, but they are there.

 

-- Rich --

 

3.58 pm today I placed a message in reply to a 3.00pm message from cocusflute. On re-checking my message I found that the computer had hijacked three paragraphs from the original cocusflute message and printed them to precede my single paragraph. All a bit of an embarrassing mystery. The only wording attributable to me is the fourth and final paragraph of that 3.58pm message.

[wntrmute]

Click your earlier post, and hit 'edit' add the phrase {/quote} where you want the quoted part to end; just replace the {}'s with the square one's [].

[Dan Worrall]

Am I to assume that the fabric backing behind my instruments fretted metal ends is purely to filter dust and other foreign bodies from entering the inner mechanism and that it has no effect whatsoever on the overall tone emitted from the instrument. I'm not prepared to experiment with my own instrument as I am perfectly happy with it's existing tonal balance. But if I were to drape a piece of the same fabric across my ears I would not be altogether surprised if it were to have the effect of possibly softening any 'shrillness'.... if it existed. I guess that different fabrics might exhibit different properties. ?? Obviously the fabric must not restrict the bellows ability to breath freely. The combinations could be endless ?

 

Rod,

 

Check out Bob Gaskins' study of this topic: http://www.concertina.com/gaskins/baffles/index.htm

 

Cheers,

Dan

[Rod]

Am I to assume that the fabric backing behind my instruments fretted metal ends is purely to filter dust and other foreign bodies from entering the inner mechanism and that it has no effect whatsoever on the overall tone emitted from the instrument. I'm not prepared to experiment with my own instrument as I am perfectly happy with it's existing tonal balance. But if I were to drape a piece of the same fabric across my ears I would not be altogether surprised if it were to have the effect of possibly softening any 'shrillness'.... if it existed. I guess that different fabrics might exhibit different properties. ?? Obviously the fabric must not restrict the bellows ability to breath freely. The combinations could be endless ?

 

Rod,

 

Check out Bob Gaskins' study of this topic: http://www.concertina.com/gaskins/baffles/index.htm

 

Cheers,

Dan

 

Dan,

 

Many thanks Dan. The Bob Gaskin's stuff looks fascinating and I would never have found it without your friendly intervention. I shall print it off and look forward studying it in detail this evening. Rod.

[Frank Edgley]

There are several ways to affect the tone on your concertina. If you're not happy with the tone, why not talk to Harold? He is a great guy and more than willing to work with owners of his concertinas. Most concertina makers are not content to come up with a design and then keep on making it without regards to improvement. Depending on the age of your instrument, tonal improvements have probably been made since its construction. I know that if this is an older instrument, you may feel that you could not call the maker. However, I think most makers would appreciate a call first to them rather than a negative comment on the forum.

[ttonon]

Is it then possible to "fine tune" a concertina by altering the reed chambers to bring each note into greater balance with the whole - such as dampening the shrill notes at the top of the octave?

For a lengthly discussion on some of the theory behind your question, you can read my article, "Reed Cavity Design and Resonance," in PICA, Volume 2, at: http://www.concertina.org/pica/index.htm

Best regards,

Tom

www.bluesbox.biz

[Dirge]

Most concertinas have no fabric fret coverings at all. I don't think that dust/hair/lint/etc. is a problem as foreign bodies entering the box rarely happens or causes problems. In fact I don't think it's happened once in the 20+ years I've had my Wheatstone. But I *do* note that stuff does occasionally impede reeds from responding well, and that "stuff" nearly always originates from the making of the instrument (sawdust, flocking, chips) with the lesser the quality of the instrument the more problems of this nature. So in effect that fabric is keeping the stuff IN.

 

So why have fabric? Most likely for appearance, and vestigial of accordion-making.

 

-- Rich --

I have to disagree violently with you here Rich; I regularly have to remove what is obviously sweater fluff from my Wheatstone, and seem to spend most of my time playing the wretched thing with duff notes because I'm putting off sorting it AGAIN. You may never have had this but it's probably monthly for me. There is one particular culprit sweater, which I don't wear much now precisely because of this, but others can provide the necessary furball too. It's an infuriating nuisance. When the weather's warm the problem abates.

 

Currently I have several bits of cloth and the dreaded white glue and am now putting off installing it as I agonise whether the weave of the chosen swatch is open enough to not restrict the breathing; in the mean time several notes are jammed with fluff and awaiting a fix, but as I'm going to 'sort it' the situation has got even worse than normal. Soon I'll have my own concertina dummy keyboard...

 

Editted to add that this is on my 71 key which has no gauze; my 67 key, which is probably played as much, has what looks suspiciously like dyed hessian dust filter and I get no problems with that, so I can even supply a control for the experiment!

Edited July 2, 2008 by Dirge

[m3838]

Currently I have several bits of cloth and the dreaded white glue and am now putting off installing it as I agonise whether the weave of the chosen swatch is open enough to not restrict the breathing

No cloth, except specially woven against dust mites, will restrict breathing.

Instead of white glue you may use tacky glue. It's cleaner, holds well, and can be redone.

[Dirge]

Currently I have several bits of cloth and the dreaded white glue and am now putting off installing it as I agonise whether the weave of the chosen swatch is open enough to not restrict the breathing

No cloth, except specially woven against dust mites, will restrict breathing.

Instead of white glue you may use tacky glue. It's cleaner, holds well, and can be redone.

Thank you. I'd better get on with it I suppose. It's either that or sort out the Morgan's electrics; I really ought to get one or other done this weekend and it's chilly at the moment...

[Dana Johnson]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

I would think so though the effect may be nil to minor depending on your instrument. Most hybrid makers have all wood chamber parts while traditional concertinas use the bellows frame gasket chamois for that part of the chamber enclosure. I would think that the addition of leather surfacing or alteration to rougher surfaces would have far less sound dampening effect on a vintage concertina than on a hybrid.

It's interesting that the Herrington... doesn't have reed chambers. Do other hybrids likewise have no proper reed chambers?

HH's concertinas *do* have reed chambers, as do all other hybrids. They are constructed differently, and might appear to be quite different from traditional concertinas, but they are there.

 

-- Rich --

Harold once told me about trying lined chambers to cut the high overtones with some success in his experiments, it should make a noticeable difference on any concertina. Mind you this is a way to turn a poor situation into a better one, but when ever you start subtracting energy from the reed's output, you start to affect their quickness to speak. Better to increase the lower overtones and fundamental rather than reduce the high overtones. Same tone balance, but now the concertina is more responsive rather than less. Most Hybrids I've heard tend to lose the strength of the fundamental and the lower overtones the lower in pitch you go. Some are still pretty good, others are dreadful. An area worth some work.

Dana

[ttonon]

Suppose certain notes were too bright, say in the upper octave. Would lining the offending chamber walls (or parts of the chambers) with a thin piece of fabric or leather - or just roughing up the chamber walls - make the sound less piercing or shrill?

In Acoustics, the technique you refer to is called porous absorption of sound, and to be effective, the porous material should have interconnected pores and be thick enough to cause significant attenuation for frequencies above a given frequency. As a rule of thumb, thickness should be at least a tenth of the wavelength of the sound you want to attenuate, but ideally, it should be more like a quarter of a wavelength. This is because the porous material dissipates energy by air friction, which requires air motion, and air motion is at a maximum a quarter wavelength away from a rigid surface. Let's take a conservative example and say you want to attenuate sounds with frequencies around 4,000 Hz and above. In other words, let's say you want to diminish partials of some offending notes that have frequencies at and above 4,000 Hz. The wavelength at 4,000 Hz is about 0.25 inches, and so the porous absorber should be at least about 0.025 inches, and much better, about 1/16 inch, in thickness. To attenuate frequencies lower than 4,000 Hz, you would need greater thicknesses, and for frequencies higher than 4,000 Hz, you can do with thinner materials.

 

Best regards,

Tom

[ragtimer]

The wavelength at 4,000 Hz is about 0.25 inches, and so the porous absorber should be at least about 0.025 inches, and much better, about 1/16 inch, in thickness.

Did you mean to say that the wavelength of 4 kHz is 0.25 FEET, or 3 inches?

Sound travels at about one foot per millisecond, so 1,000 Hz has a wavelength of 1 foot. This jibes with teh lengths of organ pipes.

 

Still, it seems intuitive that even 1/16" of soft material would absorb some high frequencies of sound.

 

But I also agree that it's better to bring up the middle and low range of a box, than to deaden the upper region. Most boxes I've played (very few) have weak upper notes anyway. --Mike K.

Edited July 4, 2008 by ragtimer

[ttonon]

The wavelength at 4,000 Hz is about 0.25 inches, and so the porous absorber should be at least about 0.025 inches, and much better, about 1/16 inch, in thickness.

Did you mean to say that the wavelength of 4 kHz is 0.25 FEET, or 3 inches?

Sound travels at about one foot per millisecond, so 1,000 Hz has a wavelength of 1 foot. This jibes with teh lengths of organ pipes.

 

Still, it seems intuitive that even 1/16" of soft material would absorb some high frequencies of sound.

 

But I also agree that it's better to bring up the middle and low range of a box, than to deaden the upper region. Most boxes I've played (very few) have weak upper notes anyway. --Mike K.

Hi Mike,

Thanks for the correction. Silly me for the gross error. When I first read the suggestion to take out harsh tones by means of porous absorption, I was skeptical, then, deciding to do the calculation, I was going between metric and English units and confused myself, being influenced by the apparent practical convenience the numbers showed. Looking at this fresh now, the 1/16" soft material would theoretically be useful to damp frequencies above 48,000 Hz, but basically useless for frequencies in the range of most human capability. For frequencies above about 14,000 Hz (about the limit of my own hearing), one would need a thickness of at least about 0.1 inch (for 1/10 wavelength thickness). But this would of course offer no effect with my hearing. For the original 4,000 Hz and above partials, we'd need thicknesses at least around 0.35 inches. Such may be difficult to incorporate into actual instruments, without causing problems. Perhaps there are very porous reticulated foams that one could try. As I mentioned before, the pores should be interconnected and distributed throughout the material.

 

Best regards,

Tom

[d.elliott]

This thread reminds me of a brass reeded bass, this was a 'C' bass and went up all the way through the baritone range as well.

 

The OEM had clearly recognised the tonal differences between the upper octaves and the bass end of the concertina's compass, because they had fitted 3mm spruce baffles. These baffles were shaped so they masked in part the mid tones, none of the lower tones and all of the upper tones. The result was a bell shaped cut-out from the spruce, a bit like a template for a normal distribution curve.

 

The baffle seemed to work well

 

Dave E