History on ohm A's and F's.

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.

Hello Darkmoebius, all...

Thank you for inviting me back to the discussion . I am a little disappointed that I was basically ignored on my last posting of the 23rd, so I just stayed out of it.

Furthermore, It upsets me that some people just refer to me basically as the “repair guy”, when I produce a brand new and fully viable line of Walsh “style” drivers known as the TLS series. www.hhr-exoticspeakers.com

True, I have remained closely akin to the original designs, but where else can you find a true single driver capable of covering the audio range without crossovers, ports, and supplemental drivers of any kind.

Note: I also have full carbon fiber cones and high energy Nd magnets system on the drafting board, but they are a ways off yet.

Anyway, my frivolous comments are as follows…Bending wave schmendig wave…piston schmiston…it’s just a matter of semantics at best. So what if the GP vc is elastomerically connected or mine is hard fixed. I can do that with silicone. Bottom line, the vc still controls the movement of the cone and the cone is launched forward in a bending wave fashion or a pistonic fashion depending upon the wavelength. Additionally, the mass of the vc controls the upper end and transient response. GP still uses an Aluminum edge wound vc same as mine. And both drivers are made of Titanium foils exactly the same size. T/S parameters still apply as well.

I agree with Mapman, The old design “F” and “A” or my new design TLS remain full bandwidth drivers while GP avoids the issue of drivers being destroyed by overdriving them by utilizing a separate bass driver and crossover system with a Helmholtz resonator and an MDF box. The bass on my drivers simply blows away the GP series in all but the best of their line. (this is not my sole opinion, but as supported and reported to me from other listeners)

I applaud DDD and all they have accomplished, but the True full range Walsh “style” speaker is FAR from dead.

Can you overdrive and crush my drivers like a bear can…Yes, you can. Can you overdrive and short out the best electrostats? Yes, you can? Can you overdrive the best ribbons of the day such as Apogee or Analysis? Yes, you can. Finally, can you launch a 15” or 18” piston driver across the room? Yes, you can. Just short out the amp or drop your needle on your record and see what happens.

As far as ear deafening sound, 98db in a small 300 sq ft room is quite loud, with peaks going far above that. What more can you ask of a single 12” driver or an 18” driver. At a price point of $8.5K or 16.5K vs. A Wilson Alexandria with 6 drivers, some of which are 13” and 15” and at more than 6 ft. tall. Or, the MBL Extremes requiring a huge room and sub station to drive them at a price point of $200K. They are all still multiple driver systems with huge crossover networks and they SHOULD play louder than a single 12” driver. I don’t know about you, but I would rather have the resolution and engaging sound rather than ear destroying volume levels especially in a smnall room.

One of my clients, proceeded to utterly destroy a brand new set of TLS-I’s with no less than a 600 sq. ft. room and a pair of 1KW amps… Geee…go figure and they were amazed when I refused to cover this on warranty.

This unfortunate event has led me to “choke” design a new series of Walsh “style” subs with 15” and 18” drivers crossing a roughly 50 Hz utilizing active crossovers. So it will relieve some of the stress placed on the full range drivers and volume levels will soar. But, am I happy with using a crossover or compromising the time and phase coherency of the original drivers… NO! I am not. Still this is quite a feat and requires an extreme amount of engineering.

No, these are not available yet…soon, but they are not cheap and they are not small.

Also, I would like to mention that my drivers incorporate subsonic filters that roll of quickly to help protect the low end excursions. Still, no loss of performance here.

Here again Ladies and Gentlemen, it is all about what you can afford to spend, your actual rooms sizes, system and WAF. I do not want to get into any kind of a “pissing contest” nor would I ever belittle any one else and their experiences. I think we are all very fortunate to live in an age when so much is possible and so much has been accomplished technologically. It is all about one thing, Enjoying music, and this love has brought us all together. How much better can it get!

Sorry for my ramblings, if I failed to answer any questions, please ask me here directly. If I know the answer I will gladly post it, if not, I will give it my best to look for it.

Good listening to all, Dale

Dale,

98db in a 300 sq ft room from a single full range driver sounds pretty appealing to me!

This is as good or better than the original As and Fs, right?