Some Notes Slower To Speak Than Others

[AlexCJones]

I've been slowly learning to play MacCann Duet on a 57 key Lachenal. The lowest note on the left side is a C, but the G above that one is "slower to speak". After I press the key, it's as if some extra air needs to go through it to get it going, and it is kind of irritating since I must slow down when I get to that note when doing scale excercises (if I am on a push stroke). Also, it is making me develop a habit of only playing that note on the Draw, since the problem only happens on the Push.

 

I had the same problem with one note an a 30-key Norman G/D Anglo, paid to have an accordion guy fix it (he didn't) and ended up selling it.

 

What makes this happen, and what do I do make it stop (or rather go faster)?

 

- Alex C Jones

Edited January 20, 2004 by AlexCJones

[Robin Harrison]

Alex ,I have a similar problm on my Jeffries G/D anglo .The lowest note I play with my left pinky was so slow ,I took the end off and had a look.It was slow because there is a lump of lead on the end of the reed......On this one note,I've found I play it a little ahead of when i need it and it comes in on time.

I find my G/D is a slower instrument than my C/G( both Jeffries) and I have assumed this is because the reeds are longer.

Robin

[Henk van Aalten]

After I press the key, it's as if some extra air needs to go through it to get it going,

Alex

 

I had a similar problem that developed in my Marcus C/G but it was one of the higher notes (do not exactly remember which one). At the point that this became annoying, I was so lucky at that moment to be in Australia. During a visit to Richard Evans (Australian concertina-maker), I told him about it, and he had a look a fixed it in a few minutes. As far as I remember, the space between the reed and reed-shoe, had become to big (wide), so there was too much air leaking before the reed started vibrating.

I guess that Richard simply repositioned the reed and the problem was fixed.

 

I hope he is reading this, because he can give a much better answer and I was at that moment too much overwhelmed by all kinds of impressions (the atmosphere, the great place, all those instruments, the nice people, etc.)

 

Hope this helps,

 

Henk

[JimLucas]

The lowest note on the left side is a C, but the G above that one is "slower to speak".  [...] the problem only happens on the Push.

Various possible causes. More details would help.

 

..1) Does the reed hesitate, then begin suddenly? It might be a weak valve getting sucked slightly into the hole in the reed pan when the other G reed is playing, blocking the hole. It would then be blown free when the air pressure builds up as you play the reed that's "hesitating". One way to check this is to play the note repeatedly in the same bellows direction. If it hesitates on the first button press but not on the following ones, this might be it.

 

From your description so far, I suspect this is not the cause. If it is, a temporary solution might be to put some reverse curvature into the valve by drawing a screwdriver blade lengthwise along the underside of the valve as you press the valve down against the blade. If that does work, it will certainly be temporary, and what you really need is a new valve.

 

...2) Another possible, but unlikely, cause is the reed frame not being seated properly in its slot in the reed pan, allowing some air to leak around the outside of the frame. I say unlikely, because that problem usually causes much more obvious problems, such as rattling, wheezing, or complete silence. The precise amount of leakage to produce hesitation is difficult to obtain, and can even change with temperature and humidity.

 

But it's very easy to test. Slide the offending reed out of its slot, and then press it back in until it seats firmly.

 

...3) Most likely is that (as in Henk's example) the position of the reed relative to the frame is not optimum. There are mainly two ways in which this can happen. Since one reed exhibits the problem and the other doesn't, comparing the two may help you find the cause.

 

.....3a) As Henk described, the centering of the reed in the frame (most likely lengthwise, even if there's too much space around the sides, if the reeds are tapered) can be incorrect, leaving extra space between them, through which air will "leak". If you hold the reed up to a bright light and look through the slot where the reed moves, you may be able to see differences in spacing around the edges.

 

Unless the bar clamping the reed is not screwed down tight, this isn't a problem which "develops"; it would have been that way since the screws on the bar were last tightened. (I recently had to fix 5 reeds in an instrument which were out of alignment in this way, to the extent that the reeds were striking their frames and not sounding at all. Combined with other evidence, this led me to conclude that the instrument hadn't really been played since it was "repaired" in 1946.)

 

If this is the problem, correcting it is a job for an experienced concertina repair person. It's a delicate operation, and an inexperienced person can spend hours at it and still only make it worse.

 

.....3b) Viewed from the side, the reed should have a very slightly curved contour, with the tip ever so slightly above the surface of the frame, generally higher for lower-pitched reeds. The problem you describe can be caused by the reed being either too high or too low. It's not just the height of the tip, but also the distribution of the curvature along the length of the reed which can affect the response. A rule of thumb is that if you have two otherwise identical reeds, the "bad" one should be adjusted to the same contour as the "good" one.

 

Bending a reed, however, is another job that should be left to a "professional". Bending any piece of spring steel so that it has a permanent change in curvature, but not a sharp angle, is hard enough. Doing it on a piece as small as a concertina reed while it remains in the frame is very tricky and delicate, with the danger that a mistake could destroy the reed.

 

I had the same problem with one note an a 30-key Norman G/D Anglo, paid to have an accordion guy fix it (he didn't) and ended up selling it.

A pity that you should sell your instrument because one individual failed to fix the problem.

[JimLucas]

I have a similar problm on my Jeffries G/D anglo .The lowest note I play with my left pinky was so slow ,I took the end off and had a look.It was slow because there is a lump of lead on the end of the reed......

Robin, I think you're jumping to conclusions. Concentrating mass on the end of the reed in that way allows a shorter reed to be used for the same pitch, but does not in itself cause slow response. The radically different mass distribution in that reed means that the optimal lift and curvature of the reed may be quite different from the other reeds, and it's possible that adjusting the "set" of the reed could improve matters significantly.

 

The shape of the lump itself can also make a big difference. Is it just a blob, or is it shaped symmetrically? Is it concentrated narrowly at the tip, or distributed along the length of the reed for a distance greater than the reed width? Are its sides squared vertically with the side of the reed, or is it cut back or tapered upward, to provide a "sharp edge" where it comes close to the frame when it vibrates?

 

On this one note,I've found I play it a little ahead of when i need it and it comes in on time.

This is a technique well known to tuba players, as the air column in a tuba is so long that the time it takes to set it vibrating is perceptible.

 

I find my G/D is a slower instrument than my C/G( both Jeffries) and I have assumed  this is because the reeds are longer.

No. If it were just length, "long scale" reeds would not be a luxury option on Wheatstone concertinas.

 

A question: Do reeds of the same pitch speak more slowly in your G/D than in your C/G?

 

Lower-pitched reeds will naturally be slower to respond, because they vibrate at a slower rate, but the difference from that cause should generally be insignificant. I would expect other factors, such as the set of the reeds, hardness of the reed steel, internal tightness of the seals, and possibly even chamber dimensions vs. reed pitch to have a much greater effect.

[Frank Edgley]

Your slow response could be caused by one of two different reasons, but more information is needed. As Jim correctly stated, the problem is most likely because of incorrect "elevation" of the reed tongue.

 

1. If the tongue is elevated too high above the surface of the reed frame it will be slow to start to play if played softly. The correction would be to push the tongue down through the slot of the reed frame until the elevation is lower when the reed is at rest.

 

2 If the tongue is too low (most likely the cause) the reed will "stall" or not start immediately at higher (or even normal) pressures. The solution is to raise the elevation of the tongue of the reed by inserting a stiff backed razor blade under the reed and lifting. or bending upward.

 

The amount of effort needed to do this depends on the quality of the steel in the reed. Some Lachenal and Wheatstone reeds are not as "springy" and take the new position quite easily. Other reeds, like Dipper, Jeffries and the newer Italian reeds often need quite a bit of lifting or lowering for them to take on the new set. If you decide to try it yourself just make sure you do things slowly, taking note of the original set of the reed. Small adjustments are better than big ones, especially if you're not sure of the "springiless" of the reed. Reeds with less springiness often need to be elevated more than those with more "springiness". Trial and error, and SMALL incremental adjustments are the way to go. As frightening as it seems to see the reed bend so, it will not break unless the reed already has a hairline crack. (Within reason, of course)

[AlexCJones]

One way to check this is to play the note repeatedly in the same bellows direction. If it hesitates on the first button press but not on the following ones, this might be it.

Yes, this is what happens. I did not notice this until I tried your suggestion because when I play scales (in parallel octaves) I always have a change in bellows direction, between playing up the scale and down, because the bellows don't hold enough air to get both ascent and descent on the same stroke.

 

Thanks!