Re: [Harp-L] triple vs quadruple reed harps

[Rick Epping <rickepping@xxxxxxxxx>]

Hi Vern,

I agree that it's deflection that stresses a reed.  I believe that the
greatest degree of deflection occurs at the moment when a reed is brought
into play from a rest position, by the initial burst of air that the player
gives it in order to make it respond.  The more suitable the reed's
environment, the less breath pressure will be required to make it respond
and the less deflection will occur during the initial attack.  An example
of this can be found in a comparison of the high notes of the 270 Super
Chromonica with the old comb, with those with new comb, in which the space
in the reed cells has been reduced.  It's curious that, while a reed
responds better in the presence of an opposing reed with a lower frequency,
it also responds better in a reed cell with a higher resonant frequency
than its own natural frequency.  Reducing the depth of the highest cells in
the 270 comb has raised their resonant frequencies to above the natural
frequencies of their reeds, with the effect that these reeds require less
breath pressure to respond than with the old comb.  Similarly, the
improvement in response given to a reed by the presence of a lower-pitched
opposing reed results in less breath pressure being required to make it
respond, and therefore less deflection and less stress at the moment of
attack.

Best regards,
Rick

On Sat, Sep 15, 2012 at 9:15 PM, Vern <jevern@xxxxxxx> wrote:

>
> On Sep 15, 2012, at 9:20 AM, Rick Epping wrote:
>
> "..................................  I tend to believe that playing a
>
> reed in an environment which allows it to oscillate closest to its natural,
> or plucked frequency, is less likely to stress it than in other, less than
> optimal environments......................."
>
>
> Based on the mechanics of materials, here's a counter-argument:
>
> Amplitude/deflection (shorter radius of curvature) is the only thing that
> stresses a reed.
> The greatest amplitude/deflection will likely occur at the natural
> (plucked) frequency.
> It follows that the amplitude and stress will be less in "less than
> optimal environments."
>
> You may be incorrectly projecting the player's stress onto the reed. The
> reed doesn't care if the player's eyes are bulging, his embouchure is
> convoluted, and he is red in the face with bending effort.
>
> Vern
>
>
>