Is anyone thinking about building Walsh drivers?

Well, I'll through in my $0.02. I am not a DIYer, but here's where I would start:

The big hurdle is that most amateur speaker builders source their drivers, and sometimes crossovers, from OEM manufacturers, like SEAS. AFAIK, no OEM driver manufacturers offer a Walsh driver. So, you're talking about building a driver from scratch. That could involve fabricating baskets, coils, cone material fitting, etc.

To get an idea of how Walsh drivers are constructed, there are some diagrams with cutaways on the Ohm web site.

I see a wide variety of omni-Walsh driver profiles. The old Ohm F's driver, which was full range, was shaped much like a traffic cone. The Decware driver, which is crossed over to a tweeter at some point, looks more like the rubber part of a toilet plunger. The current Ohm Walsh drivers, I think, are somewhere in between, and are crossed over at 8kHz to a tweeter. Interestingly, I believe some of the current Walsh drivers use aluminum for the cone material.

At least the cabinet ought to be simple - just drill a round hole on top and bolt the driver to the cabinet's top plate.

If you want to go the OEM route, I would think that John Strohbeen at Ohm would be happy to sell you a set of "cans" ready to be mounted to a cabinet. I don't know if these sets include a crossover to the tweeter or not, but you can always rebuild the crossover. I have wondered sometimes how my Ohm Walsh 2000s would sound with a pricier tweeter, but I am not curious enough to actually do anything.

That's all I can think of. Good luck, and keep us posted.

I assume that you want to build a "Walsh-type" omni speaker with purchased drivers. Otherwise, you've got quite a project on your hands, per the post above. Ohm uses - what appears to be - a more conventional driver than the original Walsh design and adds a tweeter (again, per above). I don't know where you'd find available drivers suitable for this type of design, but, if you want to go the original full range Walsh route...

You might try here:

http://www.hhr-exoticspeakers.com/HHRhome.htm

I believe that this guy is actually manufacturing Walsh type drivers of the original multi-banded design.

HEy, I like this thread!

Walsh drivers are a principle. The general principles are fairly well documented. Specific Walsh driver implementations realize the principles differently.

The principle involves a downward firing driver where the sound is emitted 360 degrees in the horizontal plane via the rear of driver.

So I have read that basically any open back cone shaped driver can function as a Walsh driver. But only those that are well designed and tuned will sound good. Also making one that is full range and robust as well as being even remotely cost effective is a trick that few if any have ever mastered. I would expect only a highly skilled engineer or technician could actually accomplish this. I know of only one these days that makes the claim (see Dale Harder's "My Walsh Dream" virtual system published here on Agon).

What is not well documented and also happens to be the magic sauce is how to design and tune a driver to function well as a Walsh driver. The shape of the cone, materials used in regards to rigidity and density along different portions of the cone (to realize the wave bending aspect of a Walsh driver) would seem to be important ingredients.

To do it well, even for a limited range Walsh driver, would seem to require understanding of the principles and a lot of testing involving trial and error and tuning to get the desired results, I would expect. Could be quite time consuming R&D type work! Not for the faint of heart looking for optimal results for sure! Or maybe you get lucky and happen to stumble onto a driver that works well out of the can (ha, ha, no pun intended)?

Those who know how to do this well are generally not prone to make their intellectual property public, so I do not know if there is such a thing out there as a quality Walsh driver design spec that one can attempt to realize themselves rather than start from scratch.

I have seen an internet thread or two on the topic on other sites where DIY'ers share their experiences, but I was not able to discern much I would bank on there.

Audiogoner Mamboni is the one I know of that might have the most practical experience with commercial Walsh drivers as well as DIY versions.

Another approach I would recommend is reverse engineering.

In other words start with a quality working Walsh driver design, and reverse engineer the specs to create one yourself based on your observations and any measurements possible.

I believe that the German Physiks DDD could be considered an evolution of the original Walsh Driver.

Great idea.

Technology and materials should be there.

I liked the old Ohm Fs.

Everything else I've heard from Ohm in the last 20 years (including 'updates' or 'upgrades') has been VERY mediocre.