Comments in line.
paulhaneberg wrote:
>
> If I remember correctly an open organ pipe resonates at the
> wavelength equal to the length of the pipe. I think a pipe closed
> at one end resonates at a frequency of either twice the wavelength
> or half the wavelength, I can't remember which off the top of my
> head.
It resonates at twice the wavelength, half the frequency, or one octave
lower.
> A 64' pipe would resonate at 17.65 Hz.
> A 1' pipe would resonate at 1130 Hz.
One octave off (reference A440):
64' (CCCCC Speaking length) is 8.175 Hz
32' (CCCC Speaking length) is 16.35 Hz
1' is 523.2 Hz
Remember, this is all speaking length. The scale of a pipe with varying
width and depth will affect the height of the pipe. In other words, a
wider/deeper pipe of the same length will sound lower that a narrower one.
> One other interesting bit of organ trivia.
> Typically you would have multiple stops open at any given time.
> Every note has a corresponding pipe for each stop.
> So if you had a pipe organ with 25 stops for the "Swell" keyboard
> you would have 1525 pipes!!!
Some stops bring more than one rank into play, perhaps as many as 8, 9,
or even 10 pipes on larger instruments for a single stop pulled. With
couplers drawn and full organ, I have heard large instruments that could
have as many as 500 pipes play with the press of a single pedal key!
Regards, Scott