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In the Forum: Horn-Loaded Speakers
In the Thread: Barn Conversion - James' Project
Post Subject: Forget about the Hindenburg hornsPosted by Romy the Cat on: 2/5/2007
 Dominic wrote: |
| I'd put your sub horns above your head. There are some big issues with that but you save a lot on concrete engineering, and assuming space remains in future you could apply what you learned from the overhead wood horns to a more refined bass setup. Obviously doing it twice isn't perfect but the opportunity to get it right seems worth it. It might make some sense to try a foreshortened horn approach, ie large throat like John Dreyer's system here: http://aca.gr/pop_dreyer.htm I don't see a good way to avoid the far field listening position with a straight front horn, one can only hope to mitigate the distance a little bit. It'd be much better i think to shorten the horn from the back and lose a bit of loading than modifying the mouth and mangling the wave front. The science of the acoustics of subsonic horns in the context of an audio installation in an eclosed space is essentially undiscovered country. Several people have tried to do it but as far as i know they've all had major complaints, either of their own or by listeners. Either that or they depend on delay circuits; and still have complaints from purists. Everybody up to now has been experimenting. I keep wondering about what the horn faces, the size of the mouth often approaches other dimensions of the space, or is actually very close to the on axis wall/floor/ceiling. |
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I would like to follow up, the Dominic's replay. The idea of making bass-horns during “30 minutes after the launch”, from molded paper and to hang it above the barn on a nice pink hydrogen zeppelin is certainly attractive idea. However, I would like to stress very confidently that if you go for sub 35Hz horn then it must be a constructions employing cement, stones etc.... With the sub 35Hz we are out of the wood realm and you will need some mass. Otherwise you end up with a horn that makes WRONG VOWELS.
The John Dreyer's solution is definitely very elegant but he went for a large throat to make the horn shorter. It is not a criminal action by itself but the question is: at which frequency this horn stops to act and horn and start to act as a direct radiator? To answer this it would be necessary to see where the horn stops to give 6dB gain… To measure it in context of a room and to filters out the room's mode is VERY complicated. The brilliant part of what John Dreyer did was that even when his horns stops loading the driver then he has a good line-array at the lower frequencies… Still, if I have Dreyer’s design in my room I would be wondering what kind drivers I might put in this horns. Using 5X515G I would have way better horn-bass but using 5X515B I would have way better direct-radiator’s, lover bass… So, go figure….
Rgs,
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