Re: [Harp-L] Reeds

[David Payne <dave@xxxxxxxxxxxxxxxxxxxxxx>]

Profile of a reed is same as a profile of you. It's what you look like from the side, i.e. the thickness along the length.  I've heard it used sometimes to refer to the curve of the reed, but I think thickness is more correct. The thickness varies across the length to change how it vibrates - I think most are aware that the distribution of mass in the profile determines pitch, but there is a lot more to it. I was lucky enough to witness reeds being designed at Harrison. This was a very cool process that designs in four dimensions X, Y, Z and frequency.  
When you design a reed, you obviously don't want the stresses focused on one spot, otherwise the reed will break immediately, but you can't distribute the force evenly along the reed, because then it will play like crap. That's one of many trade offs. There is another trade off with thickness - a thicker reed has more overtones, but a thinner reed has better response. At HH, it got more complicated because our reeds were actually designed for overblows. So, out of all these variables, we added another requirement of being able to withstand the torsion stress of overblows without squealing. Another thing, they have to be consistent, one reed needs to play similar to the five reeds around it. 

When you add all the things you require from your profile together - it's a lot of stuff.  
 
David Payne
www.elkriverharmonicas.com


Elk River Harmonicas Forum now available via Iphone app, www.elkriverharmonicas.com/forum


________________________________
 From: Steve Webb <swebb@xxxxxxxxxxx>
To: Harp-L <harp-l@xxxxxxxxxx> 
Sent: Tuesday, September 25, 2012 11:15 PM
Subject: [Harp-L] Reeds
 
I am a little confused. Can someone enlighten me about reed profiles and their role in making a harp play better? I have always equated reed profile and gapping, but I think I might be misguided.
Steve in Minn.

Sent from my iPad