Re: [Harp-L] end to end reeds

[Vern <jevern@xxxxxxx>]

> On Nov 26, 2014, at 6:51 PM, Larry Sandy <slyou65@xxxxxxxxx> wrote:
> 
> Thank you Vern, for that good explanation. Would those two tone- matching reeds produce twice the volume of single reed chambers?
> 
> Short answer: No.
> 
> Long Answer:  The response of the human ear is logarithmic.  Our ears evolved that way so that the same ear that can hear the sigh of breeze through the pines wonât be destroyed by the boom of  thunder. Doubling the sound energy by adding another reed will only increase the perceived loudness by a barely perceptible 3 db.  To check this for yourself, blow the C in hole 4 of a chromatic and compare it to the loudness of blowing the two Cs in holes 4 and 5. IF you doubled the sound pressure by blowing twice as hard on the same reed, the loudness would increase by only 6db.
> 
> Vern
> 
>  
> Lockjaw Larry
> 
> 
> Sent from Yahoo Mail for iPad <https://overview.mail.yahoo.com/?.src=iOS>
> 
> At Nov 26, 2014, 1:49:21 PM, Vern<'jevern@xxxxxxx <mailto:jevern@xxxxxxx>'> wrote:
> Unless the comb were unusually thick, the longer, low-pitched reeds would strike each other. Otherwise, you can get a pretty good idea of their behavior by blowing the Cs in holes 4 and 5 of a chromatic that are linked through the playerâs embouchure. If they were not identically tuned, they would beat. 
> 
> I doubt that their position side-by-side or facing makes much difference. Each reed can affect and respond to the overall pressure in the chamber but no directional waves would travel from one reed to the other. For this reason, although a reed can feel the pressure variations created by the other reed, it has no way of knowing where the other is. The size of the chamber is so small with respect to the wavelength of the sound that no directional waves/effects can exist. See âdiffractionâ on Wikipedia. The pressure in all parts of the chamber is almost equal at any instant. At 1125 ft/sec, a local pressure disturbance reaches all parts of a .5â chamber in less than 37 microseconds. Thus there is interaction but it doesnât depend on the relative positions of the two reeds.
> 
> Every hi-fi buff knows that only one woofer is required and that it doesnât matter much where it is placed. That is because the wavelengths of the bass notes are longer that the dimensions of the room and thus are not directional. Shrink that down to the size of the harmonica reed chamber and it works exactly the same way.
> 
> I hope that I havenât given so much background that the foreground has gone underground.
> 
> Vern
> 
> 
> > On Nov 26, 2014, at 9:33 AM, Larry Sandy <slyou65@xxxxxxxxx <javascript:return>> wrote:
> > 
> > 
> > âââ.. if two identical reeds shared the same slot, facing each other on their moving ends. Unlike those reeds that are located side by side in a common slot. This configuration should permit four reeds within the same enlongated slot, two draw and two blow.
> > 
> > LL
> > 
> > -