First off, this is an exclusively private, non-commercial blog. All contributions reflect my personal opinion and are unrelated to any potentially mentioned or linked companies. For the articles, the shown pictures, logos and other links, I do not receive any fees or advertising revenues.

In my spare time I am a passionate enthusiast of analogue music reproduction, especially for vinyl LPs. In this context vintage audio gear / concepts like tube amplifiers and horn speakers always catches my attention.

Horn speakers are very fascinating, at least for me. Their history started approximately with the very first cinema speakers at the beginning of the preceding century and were intended to use together with compression drivers. This combination provided very high efficiency and dynamics and worked well together with only a few watts of amplifier output power available in these times. Although, the requirements with respect to frequency response were less demanding than today if we speak in the sense of HiFi reproduction. Especially snail horns are associated with “honky” sound characteristics by some listeners.

If we look at modern horns, we have the so-called PA-horns which often have rapid flare changes or diffraction slots at throat region in order to fulfill the CD (constant directivity) demands. My own experiences are that smooth transition horns sound more natural but personal preferences are always very subjectively. One of the drawbacks might be that these “smooth” horns have a more pronounced amount of beaming, but this could be acceptable for home setups with a rather distinct listening position.

Nevertheless, if we search for these smooth flare transition horns, we often find round horns like tractrix or spherical wave horns. Especially the latter type of horn has aroused my interest because it is based on the assumption of a spherical wavefront for creating the horn profile instead of an exponentially growing planar mouth surface. The Klangfilm GmbH company filed the corresponding patents already a long time ago and also established the German notation Kugelwellentrichter.

My own sound experiences started with a round tractrix horn which I used for HF in my open baffle speakers. These horns sound natural but to some degree show a quite pronounced beaming which always annoyed me a little.This impression was also strengthened by listening to similar horns at HiFi shows.

Recently, I came across with the question how such a round horn could be improved resulting with less beaming in the horizontal plane but by preserving the natural sound character. As a first step I prepared a spread sheet for the Klangfilm spherical wave horn and stretched the round profile to an elliptical one. But what to do with the digital results? Well, 3D printing techniques have become available for private purposes to reasonable prices already and it is assumed that the technological progress for 3D printing will be very dynamic. Thus, the next logical step is to export point clouds for resulting profiles which can be used to generate file formats for 3D printing.

The results were so encouraging that I continued my work also for other types of horns and this site is intended to share my work with the community…