A) After much time spent attempting to successfully solder the collection of parts together, I finally finished the microphone. It actually works! Very exciting...

B) I have a tube. It is made of copper. It is a nice tube.

C) The tube is 19 and 7/32 inches long, or about .488156m.

D) After recording an impulse through the tube (see picture of waveform here and hear wav file here), I calculated with snd that the period (time between cycles) of the waveform is .00290 seconds. In this time, the pressure wave travels 2*.488 = .976313m (one full round trip through the tube). Thus, I measured the speed of sound to be

speed of sound = distance / time = .976313m / .00290s = 337m/s.

E) Finally, I modeled the particular resonance of my tube (1 / .00290s = 345Hz) by creating a single click

(click 0.1)

defining the IIR echo

(define echo ; IIR version, aka feed-back or recursive delay
(lambda* (secs #&optional (att 1.0))
    (let ((del (make-delay (round (* secs (srate)))))
   (yz 0.0)                                       ; use yd, i.e., send output to delay
   (y0 0.0))
      (lambda (x0)
       (set! yz (tap del))                        ; where it comes back from delayline
       (set! y0 (+ x0 (* att yz)))
       (delay del y0)                             ; feed into delayline
       y0)
      )))

and echoing the click with the same period (.0029 seconds) and approximately an equivalent attenuation factor (I estimated .8)

(map-chan (echo .0029 .8))

That generated the beautiful sound of an impulse in a virtual pipe (listen here).