Re: [Harp-L] RE: Fatigue and Reed Life: An Objective Test?




On Apr 20, 2008, at 1:04 AM, Vern Smith wrote:

BUT, did you TELL anyone there was a ss reed in there.?

Yes.

Ok, good man.......but then, we already KNEW that. :)

Changing only the width of a reed does not change its pitch.

No, but could it make it stronger


Another way of saying that is that a wider or narrower reed would not be thicker or thinner to sound at the same pitch. It might change the loudness slightly and would definitely change the amount of breath required.

Ok, I'll buy that for a dollar. You're the engineer.

Hohner may have changed the width of the short reeds to save breath on the high notes.

That's what 'I' thought. I thought that the reed would sound with less breath if the profile was changed WITHOUT making the reed so thin as to be almost 'foil' like (and weak).


The change in width from .08" to .07" would save the player about 13% of his breath. If it cut the sound energy by 13%, that would be only -2 db and hardly perceptible to the listener.

That's what 'I thought.

If you find this difficult to believe, do the following mental experiment:

Why would I find it difficult to believe. What I was trying to say was that I felt that making the reed narrower but thicker might produce the same tone as the amount of unsprung weight would be the same. But since the metal was now in thickness (instead of width), the reed would be strong enough to handle the strain better.

Imagine two identical reeds vibrating side by side. Their shape at every instant is exactly the same. Bring them closer and closer together untill they are touching. Since they are moving exactly together, there is no rubbing. Now glue them together, and there is still no change. Then weld them together so that they are the same piece of metal...still no change. After the weld, the resulting single reed is twice as wide but still vibrating at the same pitch.

So, you're saying that width makes no difference. But does thickness matter. In other words, is it the total MASS of the reed? As you have already negated width, what about thickness. What about WHERE the weight is distributed. MY (general) concern is to get to a point whereas we can move the reed, but the thickness isn't so thin as to cause an unnecessary strain. Much the same as I feel that reeds should be polished smooth with NO milling striations NOR any tuning gouges. Tuning should be 'buffed' in, leaving a gradual infinitesimally shallow scooping.


This might require a little extra time and since time is money, a slight raise in price is tolerable. But as it sits right now, I feel that the reeds are the weak point of a harp (setting jet engine breathers aside), and while they were never intended to tolerate the abuse that they take THESE days, still some improvements could be made.

Another thought of mine was to install pressure reliefs into harps to prevent turbine breathers from exceeding their designed operating pressure.

smo-joe


Vern Visit my harmonica website www.Hands-Free-Chromatic.7p.com


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