[Harp-L] Re:On reed problems

[Snaruhn@xxxxxxx]

Hi,

thanks for the feedback of some harp friends to my subject.

Tim responded to my:    

<< ......I really doubt that embossing achieves a noticable improvement. 
<< The tolerance of a reed side to the slot wall is the thickness 
<< of a razor blade = 0.08 mm and nobody can tell me that the 
<< human ear can recognize a lesser tolerance. >>

< I have to respectfully disagree.  Things might be different in the 
< world of valved reeds played in such a way that the two-reed bends 
< are denied.  But in the diatonic world, where two reed systems are 
< the rule, this embossing plays a dramatic role.  I will agree that 
< reedslot tolerances are in every case very tight, and perhaps the 
< difference between factory tolerances and those tightened by 
< customizers are nearly imperceptible by sight.  But tightening 
< tolerances makes reeds far more responsive to light air pressure, 
< and can have a big influence on tone.  >

Agreed! I admit that I haven´t payed attention to the different physical
circumstances between diatonics and chromatics. Of course, I know
that the two corresponding reeds in a diatonic chamber are interactive.
I have yet to check whether chromatic reeds are interactive too when
bending a note. In the moment, I suggest that they do because I
assume that a "chromatic" bending shouldn´t work differently.   

< I would suggest that another method for rotating the reed around 
< its rivet is to slide a small (0.002") shim between the reed and the 
< reedslot wall, and adjust the angle so that the reed is turned.  
< I've never been able to be precise enough on riveted reeds using a 
< reed wrench turning the base.  >

Aaah, Tim, I think that to move the reed by a 0.002 mm shim won´t
work because the pressure of the rivet is simply too high for such
a thin thing. Therefore, the reed wrench isn´t provided without a 
reason to perform this job. That you hadn´t been able to move the 
root precisely might have had the reason that you tried it by using 
your mere hand power. Try this: Set the wrench and then "emboss" 
the handle by gentle strikes with a small hammer. By this way
you can easily measure out the moving power.         

< These are quite quickly revealed by Siegfried's "translucent light" 
< method, though one must take care to hold the reedplate at the 
< proper angle and to not be fooled by one's own binocular vision. >

Heehe, that reveals that you may wear spectacles like me. No, that´s
not a problem. However, if so there´s another way to use the 
translucent light. Put the reedplate into a dia projector with the 
advantage to see the excentral reed enlarged on a screen.

Now, Joe wrote:   

< My feelings on the cross tuned mouthpieces with the bigger holes: the 
< intention was to allow MORE air to get to the reeds. In actuality 
< SMALLER holes will cause more pressure (similar to water pipes) and 
< therefore should be better as greater pressure causes quicker response 
<from the reeds. I seem to remember (but it's been a long time) that the 
< straight tuned chromos had less 'jet-lag' than the new ones...But then, 
< maybe this old man is getting senile............>

No, no, Joe, though we are both "elder statesmen" to be senile isn´t the
privilege of white hairs, younger people are often more senile than older
ones. 

Indeed, straight chroms have less "jet-lag" than crossed chroms. You
correctly say "less". Of course, the straight reed layout must show 
"air holes" too when the slide is moved and the slide hole opens the
air stream for both corresponding notes for a fraction of a second.

But the crossed slide holes are twice as big than the straight holes
which results that the time to notice the "straight hole" is simply too
short. 

BTW,  the question is interesting: what was first, the crossed reed
layout or the bigger slide holes? When you take apart a crossed 
chrom you see that the answer is simple. 

To tune crossed reeds is a tricky measure. You always have to be
aware which note is produced by which reed. So, it´s obvious that
Hohner´s initial idea was to enlarge the airstream. But once they 
did it they had then to change the reed positions too. You can
easily see that when moving the slide. To play the blow and the 
corresponding draw with a big slide hole isn´t possible at a
straight reed layout. BTW, the bigger slide holes are also a cost 
factor. One have to stamp only half of the holes. ::))

Finally, Tim, an idea I got when thinking once again about embossing
the slots. 

Froggy wrote:

< I would add one thing about what has been said about the slot tolerance: 
< alright, that lok a very tiny small little mini change and move to go from 
< 0.08 to 0.02, but if you do look at the harmonica's scale, that's huge! 
< It is reducing that tolerance of 75%!! That's really big!! >

That may be but think about this. We are talking here about the 
way how to achieve a kind of precision harp. A coin or medal has always 
two sides. The one side shows a harp making fun or satisfaction to play 
on it, the other means that the slightest foreign body between the reed
tolerance can make this fun obsolete. So, as mostly in daily life you have
to arrange a compromise, n´est ce pas?

Wish you all a blessed Easter!

Siegfried