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

[Joe and Cass Leone <leone@xxxxxxxx>]

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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