Single full range driver horn design evolution. Drawing29 was the start that revealed some beginning points. Drawing30 implements those points, leading to further refinements. Drawing31 is getting closer, Tractrix throat model fully developed. Drawing32 is pretty good, but has room for improvement. Drawing33 is really close, within 0.8% (maximum deviation), less than 0.2% through the first 1/2 of the horn's throat. Designed by Jeff Robinson, first posted Feb 03, 2001 |
| There are several inspirations/resources I should mention; Jan Hedlund's horn The Oris 150 front horn Mark Andrews' horn James Melhuish's Tractrix applet (per Ketil Parow's pseudo-code) Miroslav Ivanek's version of the Hedlund horn (laminated construction from veneers for curve construction) |
| In drawing33 I was trying to simplify the layout of the ellipses and reduce the deviation from the calculated flare expansion. The weird "T" shaped backchamber had to go, I also wanted to keep the central ellipse uncut to enhance cabinet rigidity. The sidewalls can be cutout to allow access to mount speaker connectors on the inner ellipse where it forms part of the back- chamber, allowing hiding the speaker's connecting cable. |
Wild Lowther horns by Carel 5.5 meter rear loaded, plus Oris 200 |
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| I've designed a 150 Hz Tractrix front horn to go with this bass horn for those who want to build instead of buying the Oris 150. It's basically a square horn with a round throat, the transition is accomplished by quarter circle trimming of the square cormers. 210 cm^2 throat, 3620 cm^2 mouth, 43 cm length. The indicated dimensions in the drawing are not areas but are the outside dimension (size in mm) for each step. (explanation of math) (how to draw an ellipse) (handy picture) |
| Check out this front/rear horn project: Alf Lepp |
| John Inlow's new 2 way horn - here |