I stumbled onto this,
Last edited by cradeldorf; November 15th, 2012 at 04:26 AM.
Yes good article, thanks for posting.
Are you talking about the downward facing louvres that you used to see mounted in front of tweeters? If so, those are an acoustic lens that was there to control the dispersion pattern. Remember the V shaped groove near the centre?
Nothing like a great big pair of speakers to make your day.
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Slightly more complex. Think of the holes in a spray nozzle. They create a high pressure, then the pressure dissipates in a wide pattern. That isn't perfect, but should give some idea....
Your neighbors called. They like your music.
sounds like those potato masher horns...Originally Posted by Old Guy
"those sounds to which no definite pitch can be assigned are usually classified as noise"<br />harvey fletcher-1928
Yup- potato masher are acoustic lenses too. Only real point I was trying to make is "non-directional" might describe the vanes better than "directional". The idea was to create a softer edge wide pattern rather than the narrow one from a horn alone. They do alter the sound, and so have somewhat fallen out of favor. But everything old eventually becomes new again. Line arrays caused diffraction horns to make a comeback. BTW WE had acoustic lenses back in the '30's.
Interesting illustration of a circa 1960 Westrex system....
For serious geeks only:
Computer Simulation of Pressure Fields Generated by Acoustic Lens Beamformers
acoustic
Bang & Olufsen are bragging about their "new" acoustic lens technology....
Your neighbors called. They like your music.
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