Rerurn to Romy the Cat's Site
In the Forum: Horn-Loaded Speakers
In the Thread: Vitavox’s S2 Survival Guide.
Post Subject: Re: JMLC curve, 340Hz horns etc etcPosted by cv on: 4/14/2005
eyop fellas,
Romy wrote: "Here we go! Not we are taking!!! I would not need the S2 tweeter and what it dose now in 400Hz horn is perfectly enough. I would go only for the midbass S2. Something with 6” cellulose diaphragm, low to medium compression, 3-4” throat, >2T in the gap and with Fs around 80-90hz. Something similar to the Community M4 compression driver only that would sound good"
Well, the Cogent (Steve Schell and Rich Drysdale) boys are building just such a beast: field coil magnet, (possible) permendur polepieces for >2T, Fs 70Hz, throat - dunno, but at least 3" dia, reduced compression ratio relative to midrange units. They tried various diaphragms, phenolic originally but I believe have decided that carbon fibre is king [cv ducks for cover...?]. I've seen pictures of the internals of the drivers and they certainly *look* incredible. A very, very early prototype of the smaller midrange unit may be seen at: http://www.oswaldsmill.com/id29.html but you've probably seen that already.
As for JMLC, I don't have his email address, but you should be able to find his details on the web. That musique concrete site that Jan attached was very interesting - a French fella by the name of Marc Henri did some interesting research on the damping properties of different horn materials. He uses a similar flare horn as I have for the S2, but made of plaster of paris IIRC.
Guy:
My 340Hz/T=0.8 flare horns were made by expat Martin Seddon in Oz. They have a threaded moulding and screw right on to the S2... sort of. The moulding compound shrunk a bit which meant they didn't quite fit to start with, however, they went on to my RCA drivers a treat. A few removals/re-attachments and now they fit onto the S2s too :-) With this knowledge, I'm sure he could make you a pair that would fit straight off.
I'm commissioning Martin to build me some 160Hz horns with the same mounting... should be interesting with the RCAs, which can go down low allegedly (circa 5" phenolic dia with felt surround). May also be making some 5-600Hz JMLC flares for me - the idea being RCA 150-1k, S2 1k+, if the RCA works well down there.
What's your email address? I'll put you guys in touch.
Cheers
cvRerurn to Romy the Cat's Site