Jeffries Reeds

[Seán Ó Fearghail]

Hi, I've been reading a few bits and pieces about Jeffries reeds in particular and it has come up a few times that they were made out of Stainless spring steel rather than carbon spring steel, is this true and is that what gives them that unmistakable sound?

thanks

Sean

[Theo]

Hi, I've been reading a few bits and pieces about Jeffries reeds in particular and it has come up a few times that they were made out of Stainless spring steel rather than carbon spring steel, is this true and is that what gives them that unmistakable sound?

thanks

Sean

 

Definitely myth. You can easily find Jeffries reeds with rust!

[RP3]

Since Stainless Steel wasn't invented until 1913 -- long after the death of C Jeffries Sr, I think we can safely rule that out. But apparently Jeffries did use very high quality steel in his reeds. The shape and thickness of the reed shoes may also have played a role in their remarkable sound.

 

Ross Schlabach

[Seán Ó Fearghail]

perfect. thanks guy. and what about using clock springs for steel? I've also notice that they are all the same width (well the ones i've seen) Any reason for this?

[Theo]

perfect. thanks guy. and what about using clock springs for steel? I've also notice that they are all the same width (well the ones i've seen) Any reason for this?

 

Clock spring is just carbon steel tempered to spring temper, it may have been the same steel used for both applications, but I can't believe he used springs out of old clocks!

 

Reeds the same width? Probably just convenience in the reed manufacturing process and no great advantage to be had from using different widths.

[Seán Ó Fearghail]

Thats great to hear. There are so many myths and theories. Just had to clear it up for myself. Would accordion reed steel be too soft to be used to replace a broken jeffries reeds? say hohner reed steel?

Edited June 3, 2012 by ofearghail7

[Paul Groff]

Hello all,

 

Maybe the original poster misunderstood something I wrote about a particular special concertina.

 

Most Jeffries do not have stainless steel tongues, but I know of at least one Jeffries that did come to me with stainless tongues. It has the Praed St. address in the cartouche and some other features that may indicate it was a later instrument, but is labeled C. Jeffries, not Jeffries brothers.

 

The stainless tongues appear to be original in this instrument which came to me unrestored except for an unusual, old, replacement bellows. A couple of the tongues were broken but the rest were in a typical Jeffries non-equal-tempered tuning in high pitch.

 

THis instrument seems to have gone to Madras, India, based on a repairer's label added to the (original Jeffries square leather) case from a shop in Madras that may have made the replacement bellows.

 

I suspect this instrument may have been fitted with the stainless tongues in anticipation of use in India.

 

It's remarkable to see the rustfree stainless tongues mounted in typical Jeffries brass reed assemblies, with typical surface rust on the carbon steel reed-yoke retaining bolts.

 

Colin and Rosalie Dipper made a new bellows for this instrument and arranged for replating the ends, and agreed with me that the tongues must be an early use of stainless steel. Alex West and many other members of this forum have also seen or heard this instrument played.

 

The original stainless reeds have a uniquely rich tone, with more overtones but a little softer in volume and more consumptive of air than typical Jeffries reeds. The swedish carbon-steel replacements for the couple stainless tongues that were broken are just a little louder, less complex in tone, but with very slightly crisper and more immediate "attack" response than the stainless tongues -- exactly like typical Jeffries reeds I have in other similar concertinas. The original reeds do respond very well and are also quite loud, but they take slightly different handling (mainly *slightly* more air pressure) to sound as quickly as the replacements. When I have played this instrument for other players in a quiet room and drawn attention to the tone quality of the couple of notes that have more typical Jeffries reeds, other players have been able to hear the slight difference in tone, but it is pretty subtle -- not much more than the differences among various notes of a 38-key that are due to chamber/pallet positions. In general I prefer the typical carbon steel reeds for best playability and a very usable tone quality, but the timbre of this one concertina is so unique and beautiful in its own way that I have kept it as original as possible, including my attempted restoration of its original non-equal-tempered tuning at its original pitch. (I.e., since the concertina came to me with most of its original tuning intact, only a couple of reeds that had drifted slightly in pitch or were broken had to be tuned at all, to my best understanding of its original tuning.)

 

It is possible the reeds or reed tongues of this instrument were replaced since the concertina was made, but everything about the reedwork *except the kind of steel used to make the tongues* screams original Jeffries shop work.

 

PG

Edited June 4, 2012 by Paul Groff

[Seán Ó Fearghail]

Hi Paul,

I haven't actually seen the original post but i think i read something else someone put up. Thats an amazing story and thanks for sharing your info with me. Any everyone else too.

Sean

 

 

[michael sam wild]

If,as I understand, the physics is all about air movement why does the composition of the reed metal matter so much it's not like a twanging blade where a wooden ruler sounds difefrent to a steel hacksaw blade or a brass strip. Shouldn't a plastic reed be as effective , is it more the reed chamber dimensions?

 

Mind you I'm sticking with my Jeffries' reeds!

[RP3]

Among other things, the composition of the reeds will determine their stiffness and flexibility and consequently: 1) how easily the reed will start moving in the air stream; 2) how fast the reed rebounds after its downward movement; 3) how quickly it can repeat the above; 4) what the amplitude of the reed's movements will be; and so on. All these will play a role in how the reed's movements and harmonic characteristics shape the vibrations that become part of that air movement -- or put another way -- the sound we hear.

 

Another analogy is the difference between the tone of a steel string guitar versus a nylon strung classical guitar. As is the case with the reeds, the string's composition and physical characteristics will determine how they shape the vibrations in the air making the pitch and the tone we hear.

 

Regards,

 

Ross Schlabach

[Theo]

If,as I understand, the physics is all about air movement why does the composition of the reed metal matter so much it's not like a twanging blade where a wooden ruler sounds difefrent to a steel hacksaw blade or a brass strip. Shouldn't a plastic reed be as effective , is it more the reed chamber dimensions?

 

 

But you only hear the twanging ruler because it moves the air, so whatever properties make a wooden ruler give a different sound to a steel hacksaw blade will also be at work in a concertina reed. After all the reed or ruler has to vibrate before it can make vibrations in the air.

[Chris Ghent]

If,as I understand, the physics is all about air movement why does the composition of the reed metal matter so much it's not like a twanging blade where a wooden ruler sounds difefrent to a steel hacksaw blade or a brass strip. Shouldn't a plastic reed be as effective , is it more the reed chamber dimensions?

 

 

But you only hear the twanging ruler because it moves the air, so whatever properties make a wooden ruler give a different sound to a steel hacksaw blade will also be at work in a concertina reed. After all the reed or ruler has to vibrate before it can make vibrations in the air.

Not sure this is right, you only hear the ruler when the "clamp", usually a hand, is not precisely holding the ruler at the edge of the desk. When it is held a little back from the edge what you hear is a series of blows on the ruler inflicted by the desk so the sound made is more analagous to that of a gong rather than a reed. Consequently it is not so surprising different ruler materials sound different. The more precisely you clamp the ruler the more silent it gets.

[ttonon]

As most of us realize, the sound from a free reed arises from the chopping of air by a vibrating reed tongue, called a “bar” to acousticians. We can thus divide the subject into two parts: 1) the vibration of the bar, and 2) the aerodynamic response of the air stream that interacts with the vibrating bar.

 

The problem of the vibrating bar has been solved many years ago. The simplest case is the one where the bar is of uniform (constant) cross section (constant profile and not tapered), and this solution is completely defined by the material properties of the bar and its geometry. We are talking here solely of longitudinal vibration, excluding any torsional vibration. The material properties appear in the solutions only through the ratio of the Young’s Modulus to density (Y/rho), and the geometry appears only through the bar’s thickness and length (it’s width doesn’t matter).

 

Thus, two different bars of the same thickness and length, but with different materials that have however the same ratio of Y/rho will vibrate in precisely the same way. Although this conclusion strictly applies to uniform bars, my guess is that – and I haven’t verified it -, for the same geometry (same thickness, length, taper and profile), the only material input to the vibrational behavior of a reed tongue is the ratio Y/rho. (My hunch here is whetted only from a recent glance at the derivation of the governing partial differential equation of motion for the uniform case.)

 

When we consider the aerodynamic effect on the air stream, I think it’s reasonable to say that, if two reed tongues are governed by the same equation of motion – as they would be, with the same Y/rho -, their aerodynamic effect on the air stream is probably the same. So the entire issue, when comparing the sound made by reed tongues of different material, (I believe) comes down to what difference there is in their ratios of Young’s Modulus to density (Y/rho).

 

I agree that such a conclusion doesn’t answer all the questions that arise here, particularly with regard to whether some materials will produce “better sounding” reeds than other materials. But maybe we can eek something out here. I should mention first that a complication that arises here is that, to produce the same frequency of vibration, two different materials having different Y/rho will require different geometry (particularly thickness). There is thus a cross effect from material properties to geometry, concerning the effect of a given material on reed tongue vibration, and presumably, this cross effect will also carry over into the sound.

 

But the results I present here can shed some light on questions such as, would a plastic reed tongue sound the same as a wooden reed tongue, or a metal reed tongue? The answer is that, if the ratio of Y/rho differs among these materials, then it’s reasonable to expect that their resulting sounds will differ, unless some miraculous happenstance occurs.

 

But feeling adventurous, we might venture a corollary, such as, the closer the ratio of Y/rho is between two materials, then the closer will their resulting sounds be. That is, even though there is a cross effect between Y/rho and geometry, it might very well be that this effect does not completely destroy such a corollary.

 

Let’s take some examples. We can look up material properties for the following materials: Spring Steel, Series 300 (Austenitic) Stainless Steel, Series 400 (Martensitic) Stainless Steel, type 467 Brass, and Polycarbonate plastic. From Matweb, I chose values at the higher range for Young’s Modulus and density, which is more constant, for these types of materials, with the results for Y/rho as follows, having units 10^10 x (in/sec)^2: Spring Steel, 4.15; 300 series SS, 4.19, 400 series SS, 6.24; 467 Brass, 1.84; Polycarbonate, 0.413.

 

The results are interesting. I have no idea what kind of Stainless Steel makes up the reed tongues of Paul’s concertina, but the above results do substantiate the possibility that traditional Spring Steel tongues and some kind of Stainless Steels can produce similar sounds. Also from the above, some kinds of Stainless Steel can sound different. The Brass alloy I chose, 467, is a phosphor alloy Brass, which is relatively very resistant to corrosion, and I picked a high hardness (so that work hardening during operation is minimized). I have no idea what kind of brass was used in Concertinas in the past.

 

Let’s have a little more fun here. The general consensus I believe is that “Brass reed tongues sound more mellow than Spring Steel reed tongues.” Okay, if that’s the case, looking at the trend in how the ratio Y/rho changes among these materials, we might guess that Stainless Steels in the 400 series might sound more complex, with higher harmonics, than Spring Steel, and that polycarbonate might sound even more mellower or softer than Brass - perhaps too mellow or soft, or too low volume.

 

With all this speculation, we should not lose sight of the fact that it’s important for a reed tongue to be durable and have the ability to hold its tuning. An important property in this respect is the yield strength of the material. Loud volumes may stress the material and cause it to stretch, destroying the set of the tongue. In addition, there are work hardening and fatigue issues to consider. For completeness, the yield strengths of the above materials are, having units of 10^3 psi: Spring Steel, 390; 300 series SS, 260, 400 series SS, 276; 467 Brass, 24.9; Polycarbonate, 10.2.

 

I invite others to go through the materials handbooks and see how the numbers compare, but such investigation should also be accompanied by experimentation, in order to avoid too much theoretical obsession.

 

Best regards,

Tom

www.bluesbox.biz

Edited June 9, 2012 by ttonon