Ohm Speakers, thoughts?

Sean and Jamscience, thank you for your very informative posts.

Sean, I purchased the Ohm F's in early 1975 while I was working on Long Island (Huntington). When I auditioned the speakers, the gentleman who was fielding questions at the Audio store was from Ohm. I can't recall his name but he seemed like the #1 guy. I remember the price of the speakers was not in outer space and were a little more than the Bose 901's. My friend bought the Bose around the same time I got the Ohm F's and couldn't believe how stupid he was for purchasing something that sounded so inferior to what I had. To add insult to his injuring himself by self inflicted dope slaps upside his head, the F's were a couple hundred more (rememebering the details are foggy due the fact I was just out of college and hmmmmmm...maybe using some party substances at the time. LOL) I'm sure I am not alone in this aspect of youth. Regardless, I loved those speakers with or without being under the influence.

Based on what Jamscience stated about the patient (my cousin is an attorney for the US Patient Office and she had already stated as much this past weekend), then there is hope some very creative and gifted person will look at this design again and give it a whirl. I think, even built by hand, these speakers wouldn't be as expensive as was stated above. Remember, a well connected in the bizz person is going to have connections for some if not all the parts. Case in point, look at where the Von Schweikert line of speakers are being made, plus many many others.

Line: You've lost me in terms of "where do the extra spl's come from?". What "extra" spl's are you talking about? Sean
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The difficutlty of manufacturing a Walsh driver is something that I believe could be resolved by good reengineering.

In my former life as an aerospace engineer, we worked closely with a university lab who were the primary designers of very sophisticated military electromechanical equipment. Our company's part of the design job was to refine their original designs, which often disregarded little details like "how do you make it?". The term used is "producability engineering" and it appears that the Walsh driver design never had the benefit of this kind of engineering.

Lngbruno:

I think, even built by hand, these speakers wouldn't be as expensive as was stated above.

Actually, I was being facetious. (just thinking of those 60" cones!) The real problem is recreating what has already been done. It's one thing to modify an old Model F; it's another one to build it from scratch. Just a crude guess would be (per pair):

Materials - $2,000.00 - $3,000.00
Labor - $2,500.00 - $3,000.00
Outsourcing (for things that you could not afford to do as an individual) - $2,000.00 - $3,000.00
Testing and breaking in - $500.00
Things not thought of - $1,000.00

Total cost - $8,000.00 - $10,500.00

Plus the cost of getting a new patent for any new improvements. $????.??

Am I anywhere close to the mark Sean?

What is a pure Walsh driver supposed to be? This is what I think is should be. Please correct me if what I say here is wrong.

A pure Walsh would emit sound 'only' by means of transmission line, and if the driver had suspension, that would introduce a sound that is not transmission line sound, but that of a conventional speaker. So the sound being emitted from a Walsh with suspension would not be pure transmission line sound, but rather a mix of the two.

A Walsh driver generates waves down the cone material, whatever that material my be. And from what i understand, this can be done one of two ways.

One way is to generate waves by bending the cone material itself and the waves are moving at supersonic speeds and different wave frequencies will have somewhat different supersonic speeds. From what i have read, this is how the DDD works. This method requires a very thin and ridged material.

The second way, is to generate a compression wave, in which the waves are not on the surface, because there is no bending involved, the cone material itself is being compressed, (not bent). Compression waves are also super sonic.

In ether of these methods, the proper angle of the cone will depend on the speed of the wave on/in the material being used. The greater the speed, the steeper the proper angle will be. The F's use metal and sound travels much faster in metal then in plastic, therefor the steeper angle is required if a metal matteral is used for cone material. Now, if the wrong angle is used, the waves generated in the air will not line up to form a single coherent sound source, and this will create time-smear or time-delay.

The use of suspension may or may not be necessary (i don't know), but if it must be used, i do not see how it could be pure transmission line.

This is what i understand as how a Walsh driver works. Am I wrong?

From what i understand, the DDD employed the first method and the F's the second method.