Also, a "cone horn" has its cross-sectional area grow quadratically with the distance from the throat.

What about "hyperbolic horn?" Does the area grow hyperbolically with the distance? Or, is there a hyperbolic cross-section??

What is a "Tractrix horn?"

Does a "biradial horn" have sides that are cylindrical sections, one radius on top and bottom and another on sides, or something else?

Is there a good online source to read about the above topics?

Is most of the knowledge base on horns from experimental evidence, or are they well understood mathematically?

On page 174 of Martin Colloms' paperback, "High Performance Loudspeakers" (the 5th edition - "corrected"), he says that on exponential horns the cross-sectional area grows as,

c**mx where ** is exponentiation as in FORTRAN

and later says that the cutoff frequency should be

mc/4 c = velocity of sound

Should the "c" in the first equation be an "e" and should the second equation be "4pi"?

search here
http://www.audioroundtable.com/PiSpeakers/

for exponents use ^ eg 1.5^4

a well thought out search will give good results.

http://www.f16.parsimony.net/forum27133/messages/2291.htm

Cheers!

The "Quadratic Throat Waveguide" paper published by Peavy will answer almost all the questions you asked. Please download http://www.peavey.com/media/pdf/aa/qwp1.pdf

Another referance which may be of interest to you is the post "Characteristics of various horn flares" online at http://www.audioroundtable.com/PiSpeakers/messages/1623.html

Adrian

Actual horns are pretty much understood mathematically, however the behaviour of real-world speakers in these horns isn't. Result: experimentation to achieve best results.

Cheers

Also, you might want to ask your ISP when was the last time they updated their copy of the DNS. Sheri told me that the reason some people were connected to the old server after the upgrade was because their local ISP's were slow to update their nameservers.

no, sorry wayne misunderstanding
not LOST posts,but LOST favourites!

:-)
cheers!

• http://homepages.paradise.net.nz/quadroph/bs/jbl2.jpg