The first Making of a William Neile ALO SE Horn

Some time ago I presented the first article about my development of the ALO William Neile horn type and the underlying construction method. Although, most of my previous worksheets use a super ellipse for each 3D layer / spline along the horn axis. To have an alternative option for William Neile horns I have implemented the the necessary math together with evenly distributed Neile parabolas used in this context to build up the horizontal construction wave front. All William Neile (WN) horns based on the super ellipse algorithm will get the extension “SE” in their name.

By varying the Lamé exponent of the super ellipse formula many different shapes from elliptical to almost rectangular are possible. At throat everything always starts with a Lamé exponent of 2 which indicates an ideal ellipse. Of course, if major and minor axis of the ellipse are equal there will results a perfect circle at throat. If major and minor axis differ an ellipse will result. Generally, the major axis is the horizontal plane because it is intended to radiate more broad compared to the vertical plane (minor axis). For higher Lamé exponents of the super ellipse formula the  resulting shape will be an almost rectangular spline but a transition function is needed to provide a smooth transition from exponent 2 to higher values along the horn axis. A very similar procedure was already used for my spherical wave horn (SWH) and JMLC worksheets.

This article is about the first making of such a horn by DonVK who much preferred the native elliptical shape and asked for my assistance to optimize a horn for his setup. Finally, we ended by with two horn of different cut-off. This article describes the making of the first smaller version.

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JMLC Inspired Horn Calculator

I find it difficult to formulate the appropriate introductory words for a person like Jean-Michel Le Cléac’h (JMLC). Unfortunately, I didn’t have the opportunity to discuss my work with him, although theoretically it would have been possible but my interest in horns arose just a few years ago. I would have been honoured to have received feedback on my work from Jean-Michel.

Recently, I realized what meaning as human being Jean-Michel Le Cléac’h must have had for other people when I recognized that Bjørn Kolbrek and Thomas Dunker dedicated their excellent book about “High-Quality Horn Loudspeakers Systems” to him.

Here are two links to for those who are not so familiar with his work and his life: Link1Link2.

Interestingly, JMLC emphasized that we should understand his work on horns more as a method to calculate horn profiles than rather a new expansion. This is exactly how I understand it and this post will describe my implementation of JMLC’s method.

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Meshing Point Clouds for DrBA Horns

In this article I will present a step-by-step guide transforming the point cloud exported from my spread sheet calculator into a 3D triangular mesh. Although my first implementation of a simple 3D visualization was done within Excel, I started looking for a tool that can convert point clouds into 3D printable files. After a first euphoria, however, I quickly realized that an existing and properly looking stl- or ply-file does not necessarily mean that you can print it that way directly. But that’s another story.

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