Re: [Harp-L] Chromatic Harmonica note arrangement

["Vern Smith" <jevern@xxxxxxx>]

"Straight tuning"
Traditional and original arrangement.
Shorter slide movement...equal to half the spacing between 
holes.
More openings in the slide...two for each mouthpiece hole. 
One of them is active while the other is hidden behind the 
partition between holes.
Easier to understand when tuning or working on the harp.
> From my point of view, the arrangement that makes the 
Hands-Free-Chromatic possible.

"Cross tuning"
More recent arrangement.
Fewer openings in the slide...one for each mouthpiece hole. 
Easier to manufacture.
A slide opening  moves all the way to an adjacent hole when 
the button is pushed.
Longer leakage paths between openings in the slide and thus 
less leakage at a given clearance.

Although the rectangular openings in a CX12 slide are larger 
than the ones in a 270 slide, two of their corners are 
covered by the round holes of the mouthpiece.  The result is 
that the flow area in both harps is virtually the 
same...about .03 sq in. (19 sq mm) The air flow is primarily 
limited by the reed and slot.  The majority of drop from 
your mouth pressure to atmospheric pressure occurs there. 
The amount and difference in pressure drop across the 
openings in the slide with slightly different areas will be 
imperceptible.  Thus, cross-tuning does NOT provids "more 
air" to the reeds.

The player will blow/draw the amount of air through the reed 
that produces the desired response.  Even if you increased 
the opening in the slide, this would only result in an 
imperceptible reduction in applied mouth pressure to attain 
that flow.

It boils down to a trade-off between short slide movement 
and less leakage through the slide.  You pays your money and 
you takes your choice.

Vern

----- Original Message ----- 
From: "Harvey Berman" <cscharp@xxxxxxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Tuesday, November 17, 2009 9:34 PM
Subject: [Harp-L] Chromatic Harmonica note arrangement


I am mostly a diatonic player, though I have several 
Chromatic Harmonicas. Since I have been pretty successful at 
optimizing diatonics, for myself and my harp playing 
friends, I decided to tackle one of my Chromatics. So, I 
have what is probably a stupid question for one of you 
Chromatic experts. Why do some Chromatic harps have all the 
notes for the major scale of the key of the harp on the top 
plate, and the half step higher scale on the bottom plate, 
while other harps alternate the plates between notes?

If this doesn't make any sense let me phrase it another way. 
Why do some slides have the holes in a straight row, and 
other stagger the holes?

I assume that it has something to do with round holes vs 
square holes, since my Super 64 and CX 12 are staggered, and 
my 260, 270, and Meisterklasse, and Koch have straight 
holes. Does anyone know the answer?

I am just curious.

Thanks

Harvey Berman
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