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haralanov wrote:

Your midbass horns have delay with decay, because there are a lot of internal reflections (acoustic resonances) that takes some time to settle down below the treshold of hearing. It can not be compensated by "special type of amplification"... These resonances could be controlled only mechanically by making some kind of "acoustic diode" that absorbs the energy of the sound that is reflected back to the neck of the horn. Something like this…. The drawing is very rough, but it allows you to get the idea. The blue spray illustrates the damping material.

Brilliant thinking, haralanov.  I like the idea of  acoustic diode, even if  do not know if it would be affective s we do not know the true reasons why fast notes have issue with bass horns, You feel that it is due to settling down the internal reflections but I am not sure if it is the reason. It very much might be the re-entry reflections. With the mouth of this size the horn become a very sensitive microphone… I can give another few reasons why the effect might exist. They are all hypotheses and there is no conformation what is the true reasons. You need to understand that all horn knowledge that we have and all horn theory that we visualize exist only for static applications and no one deal with transients processing by horns.

Last night I called to Bruce Edgar and asked him if anybody in past dealt with the notion. He pretty much confirm that no one look into it seriously. If Edgar does not know it then no one does, that is for sure. Bruce pointed me out to any interesting scientific thing that I did not know – the group velocity. The applied idea is the propagation of groups of short pulses across the horn would follow different principles then one long pulse.  I think I need to drive pulses and squares across my bass horn and to see what is going on.

I like the idea of acoustic diodes but it might be not so simple and we might need some sort of acoustic semiconductor as the presses that make the short notes to sound different then long notes might be not as linear as internal reflections are. I do not have answers now and I need to consult with more people about it.

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