Re: [Harp-L] Reed slot needs to be shortened

[Vern <jevern@xxxxxxx>]

Sadly, it is not that simple.  Filling the slot isn't the real problem.  Designing a longer reed having the same pitch and response as the "correct" reed is.  Designing and fabricating such a reed is more difficult than shortening the slot.

Reed design involves not only reed length but the thickness profile (the non-linear taper from rivet to tip.)   A reed of a given length works well over only a short range of pitches.  If this were not the case, all harmonica reeds would be the same length!  Below that range, the reed becomes too limber near the rivet.  Above that range it becomes too thin near the tip. In fact, the lengths are different for every hole.  Hohner and Seydel have had more than 100 years to optimize reed design.

Reeds are made for a set of about 20 standard metric slot lengths that cover four octaves from C3 to C7.    It is unlikely that you will find a standard reed close to the desired length and pitch for the overlong slot length.  

You can probably find a longer reed but it will be much lower in pitch.  Tuning it up to pitch would involve removing material near the tip.  A reed with a paper-thin tip will not behave the same way as a reed of the "correct" length.  Its response to player breath pressure would be different and it would stand out from the response of its neighbors..

It is better to adapt the slot to the standard reed than vice versa.  Otherwise you are faced with the same problem when it comes time to replace the reed.

Vern


On Oct 30, 2010, at 3:05 AM, Zombor Kovacs wrote:

> I donno if I understand the problem correctly, but if the slot is too long for 
> the reed, why dont you use a longer reed instead?  Just cut it to the right 
> length and there you have it. 
> 
> Zombor
> 
>