Antone Atmarama Bajor wrote on Sat, 27 May 2006 14:53 |
Here is predicted response of 2 half space with 1 in gray.
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First thing that bothers me is the lack of any high end at all. You would need the biggest high frequency horn DDS makes to reach down to where it rolls off.
I know nothing of horn modeling so perhaps this can be taken cars of somehow???
For an 80Hz horn I have direct experience using straight horns, both made by Community.
My first PA used a Community FRC/B with a single 15” woofer.
I was talking it over with AL Limberg and best we can guess is the horn mouth was 42” wide by 32” high by 36” deep.
This put out 80Hz, but not one cycle lower. When I pushed it running full range below 1200Hz I had to use double gaskets on the 15” to keep the surround from striking the horn throat.
From 80Hz up it was one of the most efficient, punchy and just plain nice to listen to speakers I have ever used. With a sub under and a 2” compression driver over very few 3-way designs could touch for volume without distortion. It lost favor because it was not arrable and just plain too big, thought it was very light in weight compared to what it put out.
Next is the Community “Boxer” flare.
The original design was a flair that held dual 15” (or dual 18”). The flare was 28.5” wide by 48” high by 36” deep. This slipped into a box that was the same width, but 60” high and 45” deep. You put the flare in the middle giving you a 6” by 28” port above and below. The rest of the box volume left over from the flare was used for a ported solution. There were curved ribs on the sides, top and bottom for bracing. Some really big panels to brace.
Al built a box only 48” and made a very small sealed volume the drivers shared.
This measured dead flat from 80Hz to 1200Hz and sounded wonderful with LAB subs below and M-4 midrange above. For lighter gigs he ran it all the way down to 40Hz with EQ, but you had to be careful. (One of the advantages of a sealed vs ported design.)
If I had to make a serious mid-bass this is it. Just curve the sides of the flare with some bending plywood or carbon fiber if you are fancy.
A smaller mouth or less depth is a real compromise, not that we don’t do it every day…