I was going through some old (well if 1992 counts as old) brochures
last night and came across a couple of cool EV ones. One of them had a
lot of details and products in it, even stadium horns and such (along
with a price list, list on one of those huge stadium horns was
something like $3967.00)

Anyway, in this brochure, EV claimed they "invented" the constant
directivity horn back in 1975.

As I understand it, CD horns reduce the "beaming" of higher
frequencies as they exit the horn mouth, so you get a better spread of
highs into the venue.

It seems that virtually every HF horn these days is a CD design, and I
have noticed that along with this, most commercially available HF
horns have gone to a "flat front" design, instead of the classic
"radial" design.

Is this just a style thing, ease of manufacture? or is it an actual
requirement of the CD design?

It seems like most of the CD design is at the mouth of the horn, just
looking at flat front vs. radial designs it "looks" like a radial horn
would have better dispersion, yet flat front horns are pretty much the
norm these days.

I was browsing around on the Parts Express website and noticed that
they have both designs (flat front and radial), and both are
designated as "CD horns"...this gives me the impression that a flat
front is not a requirement of a CD design but mabye the CD designation
has gotten kind of watered down over the years.

I guess maybe another factor with flat front horns is it's much easier
to fit on in a cabinet and/or road case?

Anyway, after a number of years away from even paying attention to FOH
systems, I've gotten interested in them again and this is one of those
subjects I was just wondering about.

Thanks,

Analogeezer

(Analogeezer) wrote in message . com...
I was going through some old (well if 1992 counts as old) brochures
last night and came across a couple of cool EV ones. One of them had a
lot of details and products in it, even stadium horns and such (along
with a price list, list on one of those huge stadium horns was
something like $3967.00)

Anyway, in this brochure, EV claimed they "invented" the constant
directivity horn back in 1975.

As I understand it, CD horns reduce the "beaming" of higher
frequencies as they exit the horn mouth, so you get a better spread of
highs into the venue.

It seems that virtually every HF horn these days is a CD design, and I
have noticed that along with this, most commercially available HF
horns have gone to a "flat front" design, instead of the classic
"radial" design.

Is this just a style thing, ease of manufacture? or is it an actual
requirement of the CD design?

It seems like most of the CD design is at the mouth of the horn, just
looking at flat front vs. radial designs it "looks" like a radial horn
would have better dispersion, yet flat front horns are pretty much the
norm these days.

I was browsing around on the Parts Express website and noticed that
they have both designs (flat front and radial), and both are
designated as "CD horns"...this gives me the impression that a flat
front is not a requirement of a CD design but mabye the CD designation
has gotten kind of watered down over the years.

I guess maybe another factor with flat front horns is it's much easier
to fit on in a cabinet and/or road case?

Anyway, after a number of years away from even paying attention to FOH
systems, I've gotten interested in them again and this is one of those
subjects I was just wondering about.

Thanks,

Analogeezer
Hey, 'Geezer -
IIRC, there is (or was a few years ago) a really good page on EV's
site with answers to your specific questions. I think I even remember
a download link of their original white paper (.pdf) on CD horns vs
radial, design, etc. in case you want to get into it that deeply.
Telex might have moved it, but I'll bet if ya poke around enough
you'll find it. -kooz

I was going through some old (well if 1992 counts as old) brochures
last night and came across a couple of cool EV ones. One of them had a
lot of details and products in it, even stadium horns and such (along
with a price list, list on one of those huge stadium horns was
something like $3967.00)

Anyway, in this brochure, EV claimed they "invented" the constant
directivity horn back in 1975.

As I understand it, CD horns reduce the "beaming" of higher
frequencies as they exit the horn mouth, so you get a better spread of
highs into the venue.

It seems that virtually every HF horn these days is a CD design, and I
have noticed that along with this, most commercially available HF
horns have gone to a "flat front" design, instead of the classic
"radial" design.

Is this just a style thing, ease of manufacture? or is it an actual
requirement of the CD design?

It seems like most of the CD design is at the mouth of the horn, just
looking at flat front vs. radial designs it "looks" like a radial horn
would have better dispersion, yet flat front horns are pretty much the
norm these days.

I was browsing around on the Parts Express website and noticed that
they have both designs (flat front and radial), and both are
designated as "CD horns"...this gives me the impression that a flat
front is not a requirement of a CD design but mabye the CD designation
has gotten kind of watered down over the years.

I guess maybe another factor with flat front horns is it's much easier
to fit on in a cabinet and/or road case?

Anyway, after a number of years away from even paying attention to FOH
systems, I've gotten interested in them again and this is one of those
subjects I was just wondering about.

Thanks,

Analogeezer


A constant directivity horn "squeezes" the signal vertically in the horn throat
before the horizontal flare

Also the flares in the horn tend to be sharper angles than that of a radial
horn which uses an exponential curve.

Whether the front of the horn is flat or curved has little consequence.

One company in the '70's took a radial horn and just cut of the front of the
design fo a flat front. The result was a horn that looked lke a bow tie from
the front.
Richard H. Kuschel
"I canna change the law of physics."-----Scotty