Re: Re: [Harp-L] Bent overbends - more than a theory

["Tim Moyer" <wmharps@xxxxxxxxxxxxxxxxxxxx>]

Winslow Yerxa wrote:
> Take a naked reedplate and stand in fromt of a mirror. Put your 
> mouth on the reedplate and play one of the reeds that is facing 
> the mirror. It will play as a draw reed or as an overblow reed.
> 
> PLay it as a draw reed and bend the note down. YOu can see two 
> things with the naked eye:
> 
> 1. As the pitch goes down, the reed moves closer to the reedplate. 
> The note stops when it gets too low.
> 
> 2. As the pitch goes down, the amplitude of the vibration 
> diminishes.
>
<snip>
>
> Now, in a dual reed bend, that is happening with two reeds, so 
> there is a bit more sound reinforcement. But played at the same 
> level of effort, bent notes will still be quieter than unbent.

I'm not sure this follows for a standard draw bend on the lower 
notes of a dual-reed system.  We know that in that system, as the 
pitch goes down the primary (closing) reed diminishes in amplitude 
the participation of the secondary (opening) reed increases.  I 
think this might qualify as more than "a bit more sound 
reinforcement"; there are actually two reeds performing here.  

Overbends differ in that the closing reed is effectively choked off, 
and the opening reed sounds exclusively.  I can see how this single 
reed operating farther from its native pitch (and therefore 
operating less efficiently) might be capable of less amplitude than 
the reed sounded "unbent".  

-tim

Tim Moyer
Working Man's Slock
http://www.workingmansharps.com/