++ Announcement (23.09.2025) ++ Revoke of permission for the free use of my Calculators and Designs and IP

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Unfortunately, I no longer see any way to continue making my intellectual property available free of charge. After more than five years of giving so much to the community, my own benefit is not even close to zero, but far into the negative.

For this reason, I hereby revoke permission for the free use of all spreadsheet horn calculators and designs provided by me anywhere and, overall, the use of my intellectual property with immediate effect as of 23.09.2025!

For those who have already downloaded my calculators in the past (there have been thousands of downloads already!), I expect at least that you make a donation if you want to continue using them to support my work and to keep this blog alive. Otherwise, please delete all the corresponding files that are related to my intellectual property. Keeping any copies is not permitted. Please contact me by email if you would like to continue using my work to discuss conditions.

If you would like to use my calculators and designs in the future to build your own horns, please feel free to contact me by email. A license must now be purchased in order to manufacture any horn loudspeakers based on my intellectual property. In this case, please contact me by email and just shortly describe your project, and we can discuss conditions.

If you have already built any horn speakers based on my work, I would really appreciate it if you consider making a donation. Please also contact me by email in this case.

If you simply enjoy reading my blog and would like to support my work, please consider supporting me with a donation by contacting me via email to discuss the details.

Any commercial use of my intellectual property for the software, results, designs, CAD files, or documentation provided here remain strictly prohibited! But I am open for discussion about special conditions.

The Mysterious World of the Karlson Tube – Part II

In the first article about the original Kalrson tube, I was able to develop the BEM models and investigate the acoustic properties of this special type of horn/waveguide. I made no secret of the fact that I particularly disliked the directivity control. A few days ago, I had an exciting idea about how to modify the Karlson tube to achieve better results. The implementation wasn’t that complicated, and in the end I was quite surprised at how good the results were.

Continue reading

Round Acoustic Loading Horns (JMLC, SWH, Traktrix, etc.) – the Trumpets of Jericho?

Sometimes a slightly provocative headline is necessary to attract attention. Please don’t take it too seriously. But it should be well known that the origin of my activities regarding horn development was dissatisfaction with these types of horns. Personally, I just couldn’t live with the fact that these horns consistently focus the sound extremely narrowly (beaming). There is more or less a very small sweet spot where you can experience the full spectrum of the music. If you move away from the sweet spot, the sound image collapse very quickly. What I have also noticed repeatedly as a negative aspect is that the on-axis listening experience is often very direct, tiring, or even annoying in the high-frequency range. As always, perception is subjective, and it may well be that there are people who explicitly like this. It is important to me to emphasize that I am not claiming that my opinion is the only valid one. Nevertheless, in this article, I would like to describe and also demonstrate with help of a BEM simulation why I have come to this conclusion and why I consider these horn types to be obsolete. Continue reading