Why does the concertina sound carry farther than the sound from other instruments

[CZ in AZ]

Hey everyone - particularly those versed in the physics of sound.  

 

I play in a lot of music jams, some of which are outside in festival settings.  On occasion, I have been told by those walking nearby, that all they can hear is the concertina until they get close enough that the fiddles, banjos, guitars, bass, etc fills in the sound.  Inside the jam, the concertina is pretty well balanced with the other instruments and no complaints.  I experienced this myself at a recent festival where I heard a cajun accordion playing, and as I weaved my way through the cars and RVs to get to it, I started to hear all the other instruments.  I assume this is the same phenomenon.  At some sessions, particularly if it is a large room, the concertina seems louder in comparison to the other instruments the farther you get from the musicians. 

 

Why is this?  One of my friends suggested that the string instruments depend on a resonating chamber to make the sound.  As a result, the sound is more diffuse at its origin and therefore attenuates more quickly. In contrast, a reed instrument has air pushed through a very small opening and thus the sound is actually more concentrated at its source and travels farther. Another person suggested that reeds produce fewer overtones.  The clear central tone travels farther, but it is not necessarily louder to players that are right next to you.  

 

I don't know enough about the physics of sound to know why this happens, but I sure would like a simple explanation. 

 

Has anyone else experienced this and do you know why it happens? Looking forward to hearing about your ideas and experiences!

Claire  

Edited July 16, 2019 by CZ in AZ

[Jody Kruskal]

Hi Clair,

 

Lovely to see you at Winfield last year.

 

I've noticed this too, and even posted about it back a few years ago. Can't remember the upshot of that discussion. Can anyone find the old thread?

[Leonard]

 

[Wolf Molkentin]

9 hours ago, Jody Kruskal said:

I've noticed this too, and even posted about it back a few years ago. Can't remember the upshot of that discussion. Can anyone find the old thread?

 

I recall this former discussion too, but don't find the thread either. Anyway, it will almost certainly not be about sound projection. Concertina is a very loud and piercing instrument (apart from bad ones, or some rather quiet brass-reeded models) from nearby (fellow musicians) as well as from a distance. The "pureness" of the sound will mean that the loudness is not so much a result of a bunch of harmonics but rather of the fundamental tone in itself. Maybe the explanation will have to be along these lines...

 

Best wishes - ?

[Richard Mellish]

A major factor is that the sound from a concertina goes out sideways, so it sounds quieter to the person playing it than to everyone else, fellow musicians or bystanders. If you play at a volume that seems to you about right relative to the other musicians, it's probably too loud.

[Little John]

It's a phenomenon I've experienced too. I think it's more to do with the tonal quality of the sound. It's not just the concertina - a banjo will cut through too. At a recent folk festival I saw a morris side whose musicians consisted of several melodeons and a lone English concertina. From a distance the English shone through, but I bet the player herself felt as if she was drowning in a sea of melodeons.

 

LJ

[Jim Besser]

I'm anything but a science geek, but what I believe is this: a concertina with traditional reeds produces a very pure tone without a lot of overtones, and this cuts through ambient sound more effectively than a more overtony sound - like that produced by accordion reeds.

 

Many years ago, I sat on the outdoor patio of a pub in London, Ont., and a friend and I did a little test.

 

I was playing a Morse hybrid GD, with accordion reeds; my friend was playing a vintage Jeffries GD.

 

Sitting at the table, my Morse sounded every bit as loud as the Jeffries, maybe louder.  But friends who were listening said that away from the immediate area, the Jeffries was much more audible.  I don't know anything about the physics of sound, but I'm speculating that the purity of the sound of traditional concertina reeds projects with special effectiveness.

 

Edited July 19, 2019 by Jim Besser

[Don Taylor]

52 minutes ago, Jim Besser said:

a concertina with traditional reeds produces a very pure tone without a lot of overtones, and this cuts through ambient sound more effectively than a more overtony sound - like that produced by accordion reeds.

 

FWIW

 

Here are a couple of screenshots from Transcribe! showing the overtones for A=440Hz played first on a Lachenal Excelsior with concertina reeds:

 

 

 and then on a Morse Beaumont with accordion reeds:

 

 

The green spots are Transcribe's best guesses for the fundamental notes being played.  It looks like Transcribe! thinks that C#7 is as likely the correct note as A4 on the concertina reeds, whereas for the accordion reed it likes A7 as much as A4.  The vertical scale is amplitude in DB.

 

Here is the audio file I used for these samples: Two Reeds.mp3

 

Don.

Edited July 19, 2019 by Don Taylor

[CZ in AZ]

Hi all..... I have been researching this and building on David M.'s post in the previous thread.  After learning more about sound waves and how they propagate, here is my summary explanation. Enjoy!

 

String instruments resonate in a chamber, so their near volume is a sum of coalescing, reflecting, and circulating sound waves, some of which translate into propagating far-field waves. These larger sound-producing units (violins, guitars, bass, etc.) behave as extended sources, and thus produce more near-field power relative to their far-field signal. A small free-reed emits waves more like a perfect point-like source, and the output radiates into the far-field, like a pure dipole source. Although the concertina and accordion do have overtones and do not create a perfect sine wave, the overtones are produced from the reed, not by resonating in a chamber.  Likewise, other far-carrying instruments, banjo, and fife,  are more like a point-source, penetrating cleanly into the far-field.

When close to a sound-emitting object, the sound waves behave in a much more complex fashion, and there is no fixed relationship between pressure and distance. Very close to the source, the sound energy circulates back and forth with the vibrating surface of the source, never escaping or propagating away. These are sometimes called “evanescent” waves.  As we move out away from the source, some of the sound continues to circulate, and some propagates away from the object.

This transition from circulating to propagating continues in an unpredictable fashion until we reach the threshold distance of 2 wavelengths, where the sound field strictly propagates (the far-field.)  This mix of circulating and propagating waves means that there is no fixed relationship between distance and sound pressure in the near field, and making measurements with a single microphone can be troublesome and unrepeatable. Typically, measuring in the near field requires the use of more than one microphone in order to accurately capture the energy borne by the circulating and propagating waves.  Note that the wavelengths involved are in this range: lowest note on a bass (E) = 27 feet; lowest note on a guitar (E) =13.5 feet; lowest note on fiddle (G) = 5.6 feet; middle C = 4 feet; and 440 A = 2.5 feet. 

So in a jam, everyone is in the near field regime for those that are close to them, but it depends on the note and the volume of the instrument whether you are in the near-field for those sitting across the jam, particularly if the circle is more than 8-10 feet across.  If you are outside the jam, more like 20 feet, you are still within the near-field for the bass, but probably not for other instruments.... for them, you are just hearing the sound that is making it into the far-field. 

The directionality of the instrument does not make a difference in the far-field, but it can strongly affect the near-field. 

 

[Fane]

As someone mentioned above, the sound is going sideways out of a concertina, and high-frequency sounds tend to be more directional than low-frequency (they travel more in a 'beam' from the source whilst low-frequency sounds spread out in all directions) This means that someone walking past is probably getting a direct hit of all the high-frequency content of a concertina's sound. Other than that I've noticed that pub sessions always seem to be some sort of sonic anomaly that totally defies all known science - at one I used to go to, there was a guy who sometimes bought along a homemade Dobro which was almost totally inaudible in the circle where the session was taking place, but for some reason from the door to the gents it sounded so good it would have made Jerry Douglas vow to go home and practice more...

 

(I pointed a similar thing out to a banjo player at a session last week but all it did was open the inevitable banjo joke floodgates...)