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I'm working on an installation where the sound will probably be reproduced on a parabolic speaker; the frequency response could be worse (as low as 150Hz with a 2'-wide dish), but the frequency reproduction chart looks like a wriggling earthworm. It's all over the place with peaks and valleys, sure to make for an exciting final EQ process...

Does anyone have experience designing for such sound reproduction systems and have any advice or warnings to share?

  • This is awesome. I'm trying to build a speaker with the same style that Colin Hart has mentioned, it is going to be for guests to walk beneath and hear the audio of a video station posted on the wall in front of where they are standing. They'll be able to look through several videos, all dialogue - no music. Are you guys basically saying that parabolic speakers will project mid-high range frequencies just fine but no bass/low frequencies? I know it was a long time ago, but in case it's still valid... good luck with your project NoiseJockey! Let us know how it went. – user5502 Dec 2 '12 at 18:00
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Is this for a museum (intimate sound) or for a long throw (like outdoor walkway)? Generally the sound design is pretty similar to designing for a cell phone - not much low end, the meat of it in the 2k - 4k frequency range. Also remember that it throws mid and high frequencies way farther than a normal speaker , so keep everything pretty flat or you'll end up having weird frequency spikes as you get farther away.

Here (pdf alert) is a nice little paper on Meyer's Parabolic Speaker. If you know the speakers you're using, call up the manufacturers - engineers love talking about the products and can give you more in-depth pointers (probably more than you want/need).

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  • VCProd, I totally should've specified: Intimate sound, top-down, projecting a sound cone onto the floor from above. Thanks a lot for your advice. At least I've got a spec sheet that lists directionality for its frequency range, and we've got one on order for testing and initial staging. – NoiseJockey Feb 16 '11 at 23:41
  • Oh excellent - you'll have more range to work in with that setting. Probably be best just to play it back and see how it sounds. They're pretty funky. – VCProd Feb 17 '11 at 1:54
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I have been creating and equalizing the speakers from parabold.com and here is my feedback:

  • low end and high end get truncated through reflection
  • low end is more present if dish is bigger and thicker
  • high level frequency response can be equalized by lowering 2kHz-4kHz and boosting 500Hz-1.5kHz (one should be reasonable in the equalization, don't go further 3-4dB)
  • some spikes and holes will be present as natural effect from reflection and wave phase. If F is the focal length of your dish and L the wave length:
    • spikes at L = 2F/(n+1)
    • holes at L = 4F/(2n+1)
  • only the first/second holes/spikes should be corrected

Good luck to anyone stumbling upon this thread years later :-)

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We've got a bunch of parabolic installations at work - top-down style, projecting to the floor (from only about a foot above the listener). While I've never designed anything for one of them, I have definitely noticed that they have a wonky frequency response. Very little low end, lots of high-mids.

What will be played back? Music? Dialogue? Full range content?

Any chance you get to play with one before the install?

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From all that I've read, one thing that you are going to need to do is record the output of test sweeps, then adjust your feed EQ to bring it back into line. Good luck!

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