History on ohm A's and F's.

"Next: The Peter Dicks driver parts ways with the Ohm driver in several ways. First of all, it was modeled more accurately."

There is no doubt that modern (1980s and later) Computer Aided Design (CAD) technologies would provide a means of producing superior drivers, Walsh style included.

These tools were not around when Walsh conceived of the Walsh driver nor when Gersten attempted to actually realize the design. So practically, the concept was ahead of its time in terms of the ability for a manufacturer to realize it optimally. The tools and technology needed simply either did not exist or was cost prohibitive.

Credit goes to Dick and GP for applying the newer technologies needed to the problem practically once they became available. Credit also goes to John Strohbeen, though he took a different approach in the interest of value, robustness and good sound.

Apparently though, nobody has yet figured out a way to make it work in a robust and reliable manner in a single full range driver though. All modern designs either punt and introduce a second driver or are still somewhat fragile in the same way as the originals.

Csommovigo,

How do the GP Unicorns do with high SPLs compared to the Ohm Fs or As?

Also how much do they cost?

MAPMAN:

Unicorn will be able to produce over 100dB, especially with the carbon DDD option. I'm intending to get a pair for myself early next year. It's a very interesting design, unique non-horn horn loading utilizing coincident internal ports for tuning at various frequencies, etc.

Have you seen the web brochure?

http://www.german-physiks.com/images/stories/download/brochures/web/unicorn_mkII_web.pdf

John Strohbeen deserves tons of credit ... he managed to alter the design of the loudspeaker in such a way as to make it reliable ... damn near bulletproof. Furthermore, he managed to make a very enjoyable loudspeaker that has extremely compelling performance. When I was a teen these were being sold at a store in the mall and I was dumbfounded by how much different they sounded than any other HiFi I had ever encountered until then. They left a very deep impression.

I'll say, as well, that Ohm doesn't get as much attention as they deserve. I wish I saw some mainstream reviews of the stuff, as I think their speakers offer a lot for the money.

The Peter Dicks driver parts ways with the Ohm driver in several ways. First of all, it was modeled more accurately. While Walsh was a genius (and so was DaVinci), he was unable to accurately model the concept in a way that would make it reliable. Dicks was able to do that.

Dale Harder of HHR Exotic Speakers has been refurbishing Ohm A's & F's for quite some time now. He completely replaces the cone surrounds, new cone material with a lighter mass, and voicecoils using newer materials and technology. He now makes his own versions(TLS I & II) of the Walsh drive speakers and claims that he has solved the power handling and voicecoil issues of the past with a new driver that is more efficient and durable. Here is a list of the improvements(.pdf) he's made on the original designs with his new speakers. TLS I & TLS II specs(.pdf). Here are pictures from his website of how he makes the new speakers.

Dale seems to have more hands-on experience and knowledge of the Walsh designs than just about anyone out there. I'll send him and email and get him to join this discussion.