Is anyone thinking about building Walsh drivers?

Westborn, your not alone. The link to Dae Harder's site is worth checking out, as are the archives here on Audiogon.

I have been giving a lot of thought to this. I helped build the prototypes for the Walsh tweeter that Infinity used back in the '70's. If the cone was silver with a diamond "crosshatch" pattern (very early models) it was probably built on my kitchen table. That material was Reynolds "Diamond" aluminum foil that is probably no longer available. It was supported by 1 or so mil acetate, which thinking back was a bad idea.
I've started a thread on the DIY Audio forum to share my work towards building a semi-full range driver. I'm starting with the tweeter, since it is somewhat familiar territory, and a lot of folks out there have the old Infinity's who would like to get them working again.
Like the ill-fated Ohms, the materials used by Infinity to dampen the cones and terminate the traveling wave was very finite in it's useful life. Newer materials may offer better longevity.
Obviously it's going to take a lot of trial and error, but ultimately I'd like to think I can get something like the German Physik drivers for a lot less than 50 grand a pair.
J-

Glo,

Sounds like a rational plan.

I suspect many who are fond of the older generation (near) full range Walsh drivers and wide range DDDs in particular tend to be enamored more so with the Walsh driver top end sound.

The newer OHM CLS drivers take the opposite approach, using a conventional tweeter/super-tweeter crossed over to the Walsh driver at as high afrequency as possible, at ~ 7-8 Khz AS I recall.

I gotta say though that I find it hard to understand how anyone could not be impressed with the overall smoothness and detail including the top end that at least the newer OHM CLSs are capable of delivering. I say capable in that I find the limits so far depends on what's upstream more so than the speaker itself. I have heard major differences from absolute top notch to just so/so depending on the specifics of whats upstream feeding my OHM series 3 CLS speakers. The ARC tube amp with teh newer and pricey West German 12AX7 tubes ARC now is providing, the carefully matched BEl Canto Class D amps, and either somewhat humble phono or digital sources I use currently are in that top notch class IMH and also maybe somewhat biased opinion.

If you do it successfully for modest cost, maybe approach John Strohbeen to see if the Walsh tweeter might be utilized in the 2-driver CLS configuration maybe? That might be interesting!

Mapman-
I'm surprised The new Ohm management hasn't jumped on this myself. Infinity crossed at 10KHz, much higher than the "new" Ohm's 8 KHz.. Ohm did license the tweeter to Infinity, but it was probably done during the old regime. Maybe they forgot. The Infinity seems to have gotten a measure of critical acclaim.
The high crossover point fits Ohm's current model, and the offers the advantage of being co-incident to the primary driver's axis. The Infinity had 4 crossover points, three of them in the critical presence band, and moreover it's location on top of a larger rectangular surface without a doubt caused numerous diffraction problems.
I have listened to both the old "A" and "F" models set up properly, and personally, I think that "stuffing a pillow" behind the driver as Ohm is presently doing is not the way to go.
As far as electronics go, you are preaching to the choir.

"I think that "stuffing a pillow" behind the driver as Ohm is presently doing is not the way to go."

I think this is the standard configuration provided to enable speakers to go closer to rear wall than full omnis otherwise and allow the speaks to fit into more peoples rooms like other speakers more easily.

That may be why they pass on the omni/walsh style tweeter. I'd like to see it though if possible in order for the dispersion characteristics to be similar top to bottom regardless of whether full omni or not.

I imagine cost management is a factor in the decision making process as well. The tweeter they use sounds very good. A "custom" Walsh style tweeter would likely add cost. Maybe a premium model of some sort with a separate Walsh tweeter might fly and still come in for a lot less than GErman Physiks, mbl, and their ilk.

But I also suspect that the niche high end market is not something OHM is really all that interested in, at least in the US, although they have started to market overseas in GErmany and elsewhere I suppose where their products can compete with the mbls of the world in a larger market for much less I guess.

OHM does do full omni versions for surround sound systems normally I believe where the sound absorbing materials inside the can are omitted.