Voight pipe enclosures

Pipe enclosures were design in the 30's by Paul G.A.H. Voigt, it was subject to a patent (GB447749 (A) ― 1936-05-18). The principle is quite simple

Probably inspired by pipe organ tubes.

The image below shows the Herbert Jeschke's Voigt Pipe for a build the pipes for a undetermined 8" driver: the classical way of building the Voigt pipe.

The angle is given by

(atan (/ (+ 8 (/ 3.0 4.0)) 71.0));0.12262114279484264

(/ (* (atan (/ (+ 8 (/ 3.0 4.0)) 71.0)) 180) pi);7.025673961215487

Position of the driver: $latex2png equation$

Length of the pipe:

$latex2png equation$

Actually it should be $latex2png equation$ removing the area of the speaker at the bottom, $latex2png equation$ is the speaker resonant frequency.

Here is my hack on it with a Fonestar 3inch=7.5cm speaker (20-14.000 Hz, 8 Ω, 89 dB - 1 W/1 m)

Not really a full-driver, but for 10Eurs, who can complain.

(atan (/ 15.0 108));0.13800602365751946

(/ (* (atan (/ 15.0 108)) 180) pi);7.907162702958458

Top area:

(* 7.0 7.5);52.5

Bottom area:

(* 7.0 15.5);108.5

Speaker position:

(/ 108.0 (+ 2 (pow (/ (* 7.0 7.5)
                      (* 7.0 15.5)) .5)));40.06516757332509