In Reply to: I'm affraid that I disagree here posted by EGeddes on January 31, 2006 at 14:14:46:
Earl, I wonder if you could comment on the directivity of the Sound Lab panels. Hopefully the high-efficiency guys won't mind, as it's on topic of this discussion.The image above (assuming it shows up) shows a Sound Lab panel without grille. Ignore the text off to the side - it's talking about something else.
The Sound Labs are of course dipoles, but formed of seven vertical facets angled to approximate a roughly 90 degree arc. Each facet is 5 inches wide, and the angle between facets is about 12 degrees. I believe the result is a considerably more uniform than normal radiation pattern up and down the spectrum, as once "beaming" sets in the panel geometry would result in a 90-degree lobe front and back (in the horizontal plane). There's enough beam-widening with the 5" wide panels at the upper end of the audible spectrum to prevent "picket-fence" effects. The intention of the designer was to match the directivity characteristics of a cardioid studio microphone. The pattern shape is of course different, but I think that a dipole and a cardioid have the same directivity index.
Of course this uniformity is in the horizontal plane, and you'd have quite a bit of beaming in the vertical plane - so at best it's constant directivity in a wedge-shaped pattern from a couple inches off the floor to the top of the panel (81 inches).
SoundLab's geometry propaganda is found at the link below.
Earl, what do you see this approach doing right and what do you see it doing wrong?
Thanks!
Duke
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Follow Ups
- Question about an angled-array planar dipole - Duke 01/31/0618:56:16 01/31/06 (5)
- Tough question - EGeddes 19:30:56 01/31/06 (4)
- Re: Tough question - Duke 00:30:20 02/1/06 (3)
- Re: Tough question - EGeddes 06:45:11 02/1/06 (2)
- Re: Tough question - Duke 15:01:07 02/1/06 (1)
- But you see - EGeddes 15:14:40 02/1/06 (0)