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

["Vern Smith" <jevern@xxxxxxx>]

----- Original Message ----- 
From: <Philharpn@xxxxxxx>
To: <bren@xxxxxxxxxxxxxxxxx>; <harp-l@xxxxxxxxxx>
Sent: Friday, April 18, 2008 9:58 PM
Subject: Re: [Harp-L] Fatigue and Reed Life: An Objective Test?


> This sounds like something that would be more feasible in a Consumer 
> Reports
type of laboratory setting than on a public stage, even at a harmonica
convention or festival.

Exactly!  I agree that a public stage is not a suitable place to compare the 
fatigue properties of reeds.  The test might take hours or days or weeks 
or...................

> I say Consumer Reports (which lab and road tests consumer goods) because 
> the
test should test for things a harmonica player would likely do to a 
harmonica
while actually playing one, not some abstract test of the supersonic
capabilities of a high reed before it "fails."

A player vibrates the reed and that is what makes it fatigue.  A good test 
would also vibrate the reeds under controlled conditions. Getting humans to 
vibrate reeds to failure and in exactly same way for all reeds would be 
impossible.  A good test would make certain that every reed was subjected to 
the same conditions of operation and control or eliminate all other 
variables.  The test needs to include a large number of reeds of each 
material to average out reed-to-reed variations.

Here you have the differences in point of view of the artist and the 
engineer.  The artist says, "It doesn't mean a thing if you are not playing 
music".  The engineer says, "It doesn't mean a thing unless you eliminate 
human variables."

> Not only should the goal be to determine how long a reed made of a given
material lasts but to set up a test that can be replicated and validated.
Otherwise, what's the point?

How can you "replicate and validate" any procedure that involves humans 
playing harps?

> Continuing to collect anecdotes about reed failure or longevity may -- or 
> may
not -- provide the possible range of experience.

Probably not.

> Lab tests -- with proper scientific controls -- with every
reed material subjected to identical stress tests would reveal the complete 
range
of experience without bias or favoritism.

That is exactly what I propose.

> At the same time -- or another time -- some kind of a graphic sound 
> spectrum
test (mmm good) might show any relationship between the quality of sound
produced (as opposed to simple noise) and level of reed stress/failure.

That would be another kind of test addressing other questions.

> This in turn could provide useful information about how playing styles/air
pressure could affect not only reed longevity but sound production -- how 
the
player can get the best sound out of a harmonica without destroying the 
reeds.
Now this would be news everyone could use.

I agree that it might be useful information, but would not determine the 
effect of metal choice alone.  The question to be answered first is, "Is the 
fatigue life of SS longer than Copper alloy under typical and identical 
conditions?"

> ........This is not to say all reeds are created equal by the same firm, 
> but perhaps
the midline reeds are very similar to topline reeds............

Although I don't know for sure, I would be very surprised if a manufacturer 
did not make all of its copper alloy reeds of the same material using the 
same machines and processes.

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