History on ohm A's and F's.

To my mind, it's "hardly a reasonable accounting of the similarities". In one case, we have an actual working model of a concept just a few decades old, as opposed to some drawings done centuries ago without any known working models. The Walsh "concept" may not have been as polished as the DDD due to the fact that Walsh died before he had the benefit of computer modeling to do the intricate math. Never the less, let us not forget that the working Walsh design had an even even greater frequency range. As Walsh had little to do with Ohms production standards, let us not blame him for alleged failure rates. Let us give the credit due to Walsh, without whom "Dick" might never had the premise upon which to refine and develop the the concept into the DDD. I'm just an outsider here, and while sincerely appreciate the input of those directly involved with these most interesting speakers, I'm a bit put off by what appears to be a slanted, unconfirmed and disrespectful assessment of the genius(?) of Walsh, and this applies to others who haven't posted here as well.

"Curiously - to say that the DDD is a variation of a Walsh driver (as described in LW's patent), in a fashion, to say that the Blackhawk helicopter is a variation of a drawing of a flying machine by DaVinci. While the DaVinci is certainly elegant and inspired, the GP actually works, and works with predictable precision and reliability."

This part is a bit biased I suppose.

Has GP's DDD driver solved the robustness issues of the original FULL range Walsh drivers on the A and F?

It doesn't seem so to me since it is not full range and does not deliver the low end. Unless I'm missing something, the DDD solution appears to be to avoid the problem, ie separate the low end off to another driver to avoid the stress and wear issues associated with delivering the low end "pistonically" along with the upper range that is delivered via wave bending all with the same driver, as I believe was done with Ohm As and Fs.

For newer Ohm Walsh speakers, they've elected to deliver the low end via the wide range (still not full range) Walsh-style driver. The rational Ohm provides is that most of what most people can actually hear (up to 14000khz or so) is delivered via the single driver and that preserves a lot of the benefits of the original Walsh driver design while avoiding the inherent fragile nature apparently of the full range Walsh driver design.

UNSOUND:

I don't mean to take credit away from Lincoln Walsh ... he refined the bending-wave concept into an omni design. He also managed to create a very wide-bandwidth concept. It remained a concept, commercialized by someone else (Gersten) who invented the voice coil without which it would nto have been possible. By all rights the driver should be referred to as the Walsh/Gersten driver because of that fact.

Next: 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. It is hardly "slanted" to say that - them's the facts.

I'm curious as to why you would take it so personally that someone might challenge the "genius" of Walsh? And it's not even a challenge, per se, but rather an assessment of the facts as regards the differences between the Walsh/Gersten driver and the DDD? Why so touchy?

The Walsh/Gersten driver resulted in failure. There are very few remaining working models in the field that have not been refurbished/repaired at least once in their lifetimes, and the design was abandoned by the company because it seems to have been a guaranteed liability. Their terrible inefficiency required tremendous power just to wake the driver up, and a little bit more power melted the voice coils.

Still - it remains one of the most interesting and well-regarded drivers in the history of the industry, and credit should be given where it is due to Lincoln Walsh for having conceived of the idea. You are 100% correct to say that he was not to blame for the failure rates as he was deceased before it was ever commercialized. Had he lived, he may have been able to figure out the answers to the problems. As it stands, it was Gersten who is both to be given credit for and blame for the commercial result of the driver.

MAPMAN: You're right to assume that as the frequencies get lower and wavelengths get longer the drivers behave more pistonically. You're also right to say that the Ohm F's and A's (as well as the GP Unicrns) are the only such drivers to have behaved full range. As a result, the Ohm drivers failed often because their voice coil was called on to move the entire mass of that massive driver cone ... and the power required to make the driver "wake up" and play at decent levels was just about enough to kill the VC's.

To this day the most engineering experience with this kind of driver comes from Peter Dicks and German Physiks. Together they have logged almost 20 continuous years of R&D into this driver with access to very advanced computer modeling along the way.

It is fair to say that Lincoln Walsh was the "father" of this kind of driver. I've read the patent he filed in 1964 and it reveals to me a prodigious intellect. It is also fair to say that Peter Dicks and German Physiks made this style of driver reliable, predictable, and much more efficient.

I'm sorry, Unsound, if this somehow ruffles your feathers. I didn't mean to offend you. In fact ... I didn't think it *could* offend you.

"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?