Most readers of my blog should already be familiar with the special optimization technique for my acoustic loading horns which I have called Acoustic Loading Optimized (ALO) horns. The main focus is to get very good acoustic loading horns together with excellent and even directivity control. Almost all horns that are based solely on acoustic loading optimized profile fail in this regard because they more or less strongly focus the sound toward high frequencies.

Over the past years, I have learned a lot about acoustic horns and have continuously developed and significantly improved my inventions in this field. The results are my final generation acoustic horns, which I will be presenting in detail in the near future. The first step is the presentation of the improvement of the ALO procedure to ALOV2.

I confidently refer to these horns as the final generation because I have come to the conclusion that further improvements are virtually impossible for a horn that does not have diffraction slots, abrupt changes in the horn profile, or fins. I therefore consider this horn type to be fully developed and final. The resulting horn contour with smooth and steady transitions of the profile also guarantees very natural timbres.

When a horn is divided into a major (horizontal) and minor (vertical) radiation plane and the major radiation plane expands faster than the minor radiation plane, this presents the developer with the challenge of how the sectional horn profiles ensure the acoustic loading of the horn. To take this into account, we first need to develop an understanding of how the wavefront will propagate within the horn. To take this into account, we first need to develop an understanding of how the wavefront will propagate within the horn in a quasi iso-phase manner. If we start with a square throat entry, the square must, in very simplified terms, develop into a rectangle over the horn axis. The resulting construction wave front is of course curved. In my previous horns a super ellipse was used, but for this example we keep the rectangular shape in mind.

Square horn throat.

With ALOV1 the picture is simplified here when we have arrived a certain on the horn axis:

Simplified rectangular shape used in ALOV1

The actual form is, of course, much more complex than shown here. The existing ALOV1 method works extremely well and delivers very good results. However, if you consider the consequences for the pressure conditions inside the horn when the horizontal plane is widened significantly more than the vertical plane, then this should also be taken into account and the shape optimized accordingly. Unfortunately, I cannot go into further detail here about exactly what I changed, because the new ALOV2 process will remain exclusively reserved for my final generation horns. Nevertheless, the following image should give you an idea that the resulting shape is no longer exactly rectangular. The difference to ALOV1 is subtle, but ALOV2 improves the results in terms of directively control, where ALOV1 delivered results that, in my personal opinion, were not entirely convincing but still good.

ALOV2

I hope you’ll stay tuned for more blog articles about my final generation horns!