I do have a question regarding the bass horn designs that have been adapted from the Shearer horn?

I am referring specifically to horns like the late disco sound system designer Richard Long's famous Bertha Horn and Levan Extension module.... and their decendants (made today by companies like GSA (www.gsany.com) and SBS (www.systemsbyshorty.com))

I have read that the response from these horns are tremendous, unrivaled according to some...

while others have stated that the output is merely an Illusion....

Have any of you all tried playing with the Shearer horn design and adapting it for modern drivers? (as i understand it, the preferred driver for the current builders is the JBL 2442, back in the 70/80s it was was an Eminence 18016, after Vega stopped making the original driver used)

here is some of the spare info i have been able to get regarding the Bertha and Levan.... my understanding is that the Levan Ext is an exponential flare bolted onto the Bertha's Hyperbolic flared mouth...

The Bertha
A large multi-fold hyperbolic horn delivering full power frequency response down to 20Hz. Features two 18" drivers specially designed for high power low frequency application - 1000 watts RMS. This speaker system must be interfaced with any RLA electronic crossover.
DIMENSIONS: 42"H x 61"W x35.5"D
WEIGHT: 425 lbs.

The Levan
Our top of the line bass horn featuring the Bertha with a large horn extension for improved air coupling. This is one of the finest bass horns ever made. It will handle the largest discos with ease and provide awesome bass reproduction.
DIMENSIONS: 42"H x 96"W x 64"D
WEIGHT: 612 lbs.

Maybe we can get them to come out to the next Prosound Shootout in October 2007 and see how these basshorns stack up next to others.

I think that Paul Bell tried to get some far a PSW shootout a few years ago, but he couldn't find anyone that had a "real" pair that would drag them out to the fun....

and the builders tend to be very secretive about the box
(totally understandable, I guess)

and as I understand it, RLA had some folks at a professional woodworking shop build his cabinets...

Stay tuned...