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I know that the Mantaray MRII64 horn is a constant directivity device, but it is CD both ways, horizontal and vertical?
I am thinking of arraying 3 of these per side in the future, and was wondering about mounting them rotated 90 degrees so that the horizontal dispersion would be 40 degrees, and three of the cabinets splayed would give me 120 degre coverage with minimal overlap.
Thanks for any advise!
Hi, Charles,
Check your email for the MRII564 spec sheets. The standard "stack-and-splay" setup should work with the 40 deg. axis vertical just as well. CD does mean constant directivity in both axis'.
Typo----I meant 60 deg. axis vertical.
The tech letter on MR directivity could be the most help;
http://alteclansingunofficial.nlenet...ers/TL_241.pdf
Good article, but don't forget that this is for the original very large Mantaray horns, and the frequencies mentioned that will be controlled don't apply to the smaller MRII series of horns.
If I recall correctly, the MRII94 will maintain control down to 1500Hz, the MRII64 will only maintain it down to 2000Hz. If you start going below those frequencies on their respective horn, you will lose directivity control as it goes lower. Physical size does follow the laws of physics, and there is no way to get around them that I know of.
Good point, I couldn't find the data for the smaller MRs,
Perhaps a single MRII5124 would be more satisfactory for your app. With a 22" x 10-1/2" mouth, it should exhibit control down to around 600hz at 120 deg. horiz., and 1,200hz at 40 deg. vertical. You'd loose 20 deg. vert. coverage, but have useful 120 deg. horiz. directivity down to near XO, all in a single, small package.
Greets!
What's a MRII64, 94, etc.? I never heard of them or could find any info in a quick browse. FWIW, here's the MRII5 series specs: http://www.lansingheritage.org/image...ro/1993-27.JPG
Anyway, You're creating a virtual multi-cell, so the array will control to a much lower frequency in the horizontal plane due to the acoustically much wider mouth, and lobe with increasing frequency above ~1 WL of the summed mouth width, though not nearly as bad as the original expo multi-cells. Since there's no height increase, the lobing won't begin until a much higher frequency.
GM
Sorry to cause any confusion, I just neglected to put the 5 in front of my model numbers...I sure wish there were 40x40 horns out there, that would be ideal for arraying 3 of them.
OK, the virtual horn idea just kept running through my head. I can envision that out front of the horn it acts as a single horn, in dispersion and control. I just keep kicking back the other way though, and I would have to assume that even though out front the mouth area is doubled, that to the driver end of things, it is not, so we can't just correspondingly lower the cut-off frequency to take advantage of that large area, can we?
Greets!
You're using 'x' number of horns Vs one, so this system's acoustic efficiency has increased. This increase can be used to either play louder and/or over a wider BW.
GM