Is anyone thinking about building Walsh drivers?

I'm hoping to start a discussion that is not charged with emotion that may be useful to folks seeking to build Walsh transmission line drivers.
Any of you out there played with this seriously?
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:

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.
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.
I believe that the German Physiks DDD could be considered an evolution of the original Walsh Driver.
Westborn - I won't argue taste with you, but have you heard the current models in the Ohm Walsh line? I had never heard Ohm Walsh speakers prior to my home trial of the 2000s, so my only comparison was to other brands of speakers. IME, the 2000s compete extremely well in and a good bit above their price point. John Strohbeen has refined his products, and, obviously since I bought them, I find them to be among the best speakers out there. Of course, YMMV, but if you value warmth, detail, large soundstages, well-defined imaging, accurate timbre, and clean extension at both ends, you might be surprised by the current Ohm line.
OF course any good speaker including omnis and the newer OHMs can sound mediocre if not set up well. Personal tastes aside, the same speakers can sound absolute top notch if set up optimally.

Like most things, it all depends...

Also worth mentioning that Dale Harder's website has perhaps the most information I have seen anywhere regarding what goes into creating a quality Walsh driver. Pretty daunting....
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.

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!
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.
I can see your point concerning close wall spacing. The omni's need a lot of room to breathe, and creating the correct acoustical environment is black magic a lot of folks would just as soon avoid.
As for the tweeters, they take a lot of skilled labor to build. It's not something you can pop out of an injection mold, and the key to profits these days seems to be not paying craftsmen or worse, farming it out to the Pacific Rim.
One of the ESL companies, I believe it is Acoustat, moved their production from the UK to China to contain costs. The Chinese company immediately started selling a knock-off with a different name for about 1/3 the UK price. The Chinese seem to be very challenged when it come to intellectual property
Mapman... You can mount a conventional cone driver backwards firing down, but it isn't at all like a Walsh driver.

The angle of the cone and its material must be such that sound propogated down the cone material is delayed by a time that, at every point down the cone, matches the delay resulting from the angle of the cone. (Sorry I can't explain that better). This is the key design feature which enables its superb phase coherency, as evidenced by accurate reproduction of a square wave.

I'd say you are correct in terms of how a properly designed Walsh driver operates.

My understanding though is that Lincoln Walsh invented the principle, but never implemented a specific commercial design himself, though he was involved early on with the first early OHM products, something that no other makers of Walsh drivers can claim.

SO when I read that any conventional driver can be configured to operate as a Walsh driver (though most likely not a good one unless the principles of designing a Walsh driver are applied and realized properly somehow), I find it hard to argue. The quality of the resulting sound produced in the end based on applying the principles is what matters.

I read about people implementing their own "Walsh" type speakers using otherwise conventional drivers, but have never heard any, so I could not comment on the results achieved.

If it walks like a duck and quacks like a duck, it's probably a duck, but still not all ducks are created equal!
Eldartford is 100% correct. In the "A", the cone was two tiered and had two angles. The different angles reflected the propagation velocity of Titanium (upper), and Aluminum (lower). I think the "F' was the first in a series of compromises, in that all three cone materials were all at the same angle.
The theory behind the transmission line was detailed in a White Paper that Ohm would mail you for the asking back in the "70's. I have never been able to find it on the web, nor have I been able to get it from Ohm.
We did some experiments with two way "Walsh" speakers back then using off the shelf 10" CTS woofers and the foil tweeter that Infinity later bought.
It didn't sound too bad, and in fact a couple of musicians and wealthy audiophiles were impressed enough to consider backing a commercial venture.
Unfortunately, a profitable business model and art for the sake of art collided immediately and the project was doomed.
A lot of effort was put into dampening/stiffening the cone with things like roofing tar, and terminating the outer surround to coax transmission line behavior at the same time keeping a "back wave" from going back up the cone.
One big problem was that the roofing tar worked for a week or so, but then it started to really harden the the character of the sound began to degrade. After the business deal fell through, we never followed up.
We never did any serious tests, because we were a couple of broke kids playing with Hi-Fi and couldn't afford the gear to test with. They sounded good for a while, though
Hello Mapman, Unsound, Bondmanp,...everyone.

I think about building Walsh style drivers and speakers on a daily basis. I live and breathe it along side laser designs and builds.

Hope you folks don't mind if I chime in, but I have some new products that may interest you.

Why build Walsh drivers when you can now own a pair for DIY Projects? Under $1K.

Besides our highly redesigned TLS-1 (modeled after the old F),and the TLS-2, (modeled after the old A), we have now added to our line up, for DIY people the TLS-4,which is a Walsh style "Tweeter/Midrange" unit in a very compact package. There almost full range. See our virtual system..My Walsh Dream.

In addition we offer the new TLS-5 Hybrid, a fully Walsh style Tower for those with less space than the larger floorstanders require.

You know, we are often talked about here on Agon, but so far, none of you have come to see us, or test our products.

I began this sleigh ride years ago to share the music with fellow audiophiles, and to offer products for your pleasure, because you asked me too.

Our continued effort is on your behalf and we thank the dozens of clients that have blessed us with their patronage.

We would love to advertise or open a virtual store here on Agon, but unfortunately, they are priced well out of our range, for now. So, like Ohm Acoustics and others we rely on our clients to spread the word.

To comment on your earlier post, Lincold Walsh did develope the first Model A's with Marty Gersten, whom went on to open and operate Ohm Acoustics. Marty eventually developed the Ohm F based on the A and the special voice coils to drive them.

While Marty left Ohm in 1978, if memory serves, I did maintain contact with him until his untimely death, just about 2 years ago. This is unfortunate, as we were collaberating on other designs utilizing this pricipal.

I am here and I am happy to help anyone whom asks.

Great listening to all
Hi Dale.

I'd much rather spend my time listening to Walsh speakers than building them.

Your speakers are on my short list of designs I have not heard that I would most like to.

Right now I am happy with what I have but always looking to explore new or future options.

I would make extra effort to go to Capital Audiofest this July if I knew you would be demoing your stuff!

I still have not heard anything that I can afford that would make me abandon Walsh style speakers for my tougher applications.

I do fear though that the expertise to make the technology work well in a marketable manner is so limited that it could fall totally by the wayside someday. That would be very sad!
Okay Dale,

I may have failed some kind of IQ test here, but I just followed my own link (above, in a previous post I made to this thread) and don't see any reference to a TLS 5 hybrid on your site. You have definitely peaked my curiosity here, but I need a little help.


Is anyone thinking about building Walsh drivers?

Hi Mapman,

I do agree with you, I love to listen to them too. However, as a designer and builder trying very hard to carry on the legacy of Lincoln Walsh, there is nothing quite like hearing one of our new designs roar to life and blow you away. It is a costly technology, but worth it in every way.

Wish we could go to the shows too,... but you know, spending more than $20K to attend and set up is just not cost effective for us. Rather spend that on a new design. The economy being what it is these days places a big burden on us and many others like us.

Still, you are welcome anytime.

BTW, do you remember the Ohm G? Our new TLS-4(IV) "DIY" driver and the new TLS-5(V), really go way beyond these old beauties. Drop me an email and I will send you some pics.

Hello Martykl,

No, you didn't miss any IQ test.

The TLS-4 and TLS-5 are new offerings for this year (2012) and our "IT Team" has not caught up with us yet. We are working on getting these items on our site but it does take time.

The TLS-4 is a DIY Walsh style driver that is very compact and covers the Tweeter/Midrange in a single driver. This is designed for those that want to build their own systems.

The TLS-5 is just completing the prototype phase, (with a few on order) and is a Full Range Tower System consisting of Two Walsh style drivers and a ("gag") crossover. (You guys know how much I hate crossovers, even if they are high quality.) This system has a much smaller footprint than our big floor standers. Range is 37 to 22 kHz, 3db down points.

You can see the TLS-4 on our virtual system thread under "My Walsh Dream" Ever Evolving category. For now, until our website is fully updated, you can contact me by email and ask for pics and info.
It's been 6 years since I've tinkered with building my own Walsh drivers. It seems like yesterday - the years do fly by. I was involved with the DIY Audio Forum then and my contributions to the thread start here:

Here's my old post with the parts and materials - then costing about $200!

Build your own Walsh loudspeaker for about $250 in parts and materials:



6.8 uf high pass capacitor (metalized polypropylene) to tweeter (

4 ohm power resistor in tweeter circuit.

Sonotube: nominal dia. = 12.5 inch height = 37 inch
Stuffing: acoustastuff ~50% of internal volume

This speaker glue has consistency of Elmer’s glue when wet, dries fairly quickly (water base) to form a clear and very flexible soft clear rubber with excellent damping characteristics.

Walsh Loudspeaker: two-way X-over first order (6dB/oct) high pass filter to tweeter at 8 kHz
Woofer – full range (no crossover)
Alignment: Acoustic suspension (Vb=2.5 cu. Ft; Qtc = .816; Fc = 49 Hz (-3dB))
Frequency Response: 49 - 20,000 Hertz (-3 db, +0db)
SPL: 89 dB/watt Max Power: ~100W

Illustration: Cone with felt damping applied with speaker repair glue.
Photos #1(schematic) and #2: woofer with felt dampers and felt variovent in dustcap. Variovent consists of ¾” dia. Hole cut into center of dustcap and hole covered with three laters of felt to provide resistive vent.
Photos 3-5: final loudspeaker.

Photos of the loudspeaker are posted at the forum link above. Now the purists will say that this is not a true Walsh because the cone angle does not provide for perfect phase-time alignment - I don't know. The thing is, the proof is in the listening and these loudspeakers sound so good. In fact, I'm still using them as the fronts for my dedicated home theatre. Guests are awestruck by the wrap around seamless sound field with such clarity (I am using side and rear conventional box speakers for the side and rear channels of course). My trusty Kinergetics bsc-100 stereo subwoofers are still performing yeoman's service after over 20 years (thank you Louis Nolemi). Now maybe my improvised Walsh has slight time-phase error, and perhaps passes a parallelogram rather than a square wave - I don't know. I've come to the opinion that the ear cannot hear small timing distortions but can hear frequency response-power response disparities. Anyway, for a few dollars and a few hours of labor, you can build these and I do predict you will like the sound a lot. In fact, these were so easy to build and the materials so inexpensive that I built three pairs and gave two pairs away to a neighbor and the church pastor.

Previous to this project, I built some true Walsh steep cone drivers. Yes, they sounded excellent. But, the time and effort needed to build them was great indeed. You can achieve excellent sound from properly selected conventional woofers using the modifications I listed above and careful cabinet alignment, with a lot less time and effort.

I visit Dale Harder's site periodically and his work is just gorgeous. I have had a hankering to buy a pair of his true Walsh F loudspeakers but I can't justify it at this time. I have my Walsh 5000s and I love them. I listen to them every night and pray that they never fail; because I've finally gotten by system to sound just right in my dedicated listening room.

While I would love to build another Walsh project with different higher quality drivers in mind, I will likely never get there. My medical practice is very busy and leaves little time left over for family. Also, after a 20 year hiatus, I picked up the french horn again 7 months ago. Practice is time consuming, exhausting and rebuilding one's performance and endurancer takes many months. My goal is to win a seat in amid level amateur orchestra. I want to get back on stage - I miss performance with a good symphony orchestra. I don't know if I'll get there but I will do my best and stick with it.
Hi Mamboni.

Great to hear from you. It's been a while!

Mamboni's writings on the various audio sites about the newer OHMs and Walsh drivers in general was largely responsible for my giving the latest generation of OHM Walsh speakers a try a few years back when I was in major upgrade mode.

I auditioned everything under the sun with price no object including large dynamic designs, the latest Maggies, Quad Electrostats, Magico, Gallo Refs, and others before deciding to try the newer OHMs in house first. It took me awhile as well to get everything dialed in just right in my main listening room as well but I am still so glad I did!

Mamboni's postings on the DIY site regarding DIY Walsh speakers are the most extensive, practical and best thought out technically that I am aware of. Anyone looking to DIY a pair of Walsh speakers should start there.
Yo Mapman:

Thank you for the kind words.

I'm listening to Fistoulari conducting the LSO in a performance of Adam's Giselle, a Mercury Living Presence CD reissue, on my Walsh 5000s and I am there: it is alive!

Living presence indeed! You need a Walsh to get it.
"Living presence indeed! You need a Walsh to get it."

Yes, would have to agree.

I just received the 51 CD MLP box set and am in process of ripping to music server. I am looking forward to quite a treat!

If you take a good MLP recording to the limit with OHMs or similar wave bending Walsh speakers in general, you are sitting pretty for pretty much everything else IMHO. And it does not have to cost a small fortune to accomplish either! I really do not know of any other way to accomplish that practically?

THe wave bending and how that enables a single driver to function wide range coherently and with 360 degree dispersion so efficiently is the key it seems to me.

When I consider the physics behind this, it makes a lot of sense in terms of getting the most possible out of a dynamic cone driver.

Lincoln Walsh was worlds ahead of his time! Not sure anybody else has come up with a better way yet even after all these years.

In my mind John Strohbeen and OHM are one of the best kept secrets out there in the high audio world. Other than the sound of the speakers these days, nothing about OHM screams "high end".

I find the whole thing quite fascinating and I admire John Strohbeen immensely as a guy who is obviously brilliant but knows how to keep his ego in check and just let his products and customer service speak for themselves.
I just heard the tls 5 dale is talking about. I'm fortunate to be in Cleveland and to get to hear them. They are some of the clearest speakers I've ever heard. Plus some how he was able to crossover with no audiable issues. I a/b'd them with the big brother tls4 and they do hold there own. obviously the tls4 has better bass but my god these are amazing and truely compact in size. I ordered a set on the spot. I also have his tls4's. My wife will like the smaller size for the den and now I can move the tls4's to my bigger living room where they really belong. Beleive me you won't be sorry if you pick up a set of these for a smaller room.
Dear Sir,
My name is Stefan Wesolowski. I live in FT Worth, TX USA my mobile 703 499 6236. I have an original working MINT pair of Lincoln Walsh OHM "A" speakers.
I know of only 5 other persons on this planet that have a working pair. I would like to join your search for more info regarding the OHM A's.
Thank you.
Best regards,
Hi Stefan,
Your search is over, IMHO. I beleive I can provide you with whatever you seek regarding the True Walsh speakers.

My mane is Dale Harder and I own and operate HHR Exotic Speakers in Cleveland Ohio. Our product line, the TLS series, 1, 2, 4, and 5 pick up where the old A, F and G, left off.

We can even re-manufacture the originals and bring them up to state of the art specs, almost as good as our TLS line.

Check us out at or give me a call at 440-888-02163.

I would be happy to help you.

BTW, you can see one of our systems and some of our products here on A-gon under virtual systems, ever evolving, page 2, "My Walsh Dream"

Kind regards,
Dale Harder
Is anyone still bothering to look at this thread?

I've been tinkering with DIY Walsh 'clones' and would be happy to trade thoughts, asides, and whatever else comes to mind in the process
...nothing but the sound of crickets in the night...

Well, anyway...if you're curious...
Take a look at these links:

Best of luck with the DIY build Asvjerry.
I'm not thinking of building any in the near future but very interested in learning from what others have done.
Jerry, crickets for sure, although some times things pick up and move along nicely on things about Ohms, then tapers back off for awhile. Enjoyed your threads over on the "other DIY forum".

Hi Map, how are you doing these days?
Not sure how many DIYers in general hand out in these parts.
Frazeur I am doing well. Getting to listen to a lot of good music and work out 6 days a week amid all the rest. My wife and I will have a 25th anniversary coming up and kids are doing well in school. That's the jist of it. Best always!
Jedinite...*G* Uh, that's my file. As for the conus, that's what started me out, some 9+ years ago. (Long story, you don't need to be put to sleep by it... ;)...)

Mapman, you might take a look @ that file. *L* Meanwhile, I've moved on. Currently goofing with building a 3 way version ( T/M/W, vertically stacked) just because I don't know of anyone trying to do so.

Frazeur, then you already know about my 'idiosyncrasy' re Walshs'. Just thought I might pay this site a visit to see if there's anyone I haven't *L* 'infected' with my 'condition' yet. "Call me...irresponsible.."

As for DIYers....*L* Well, one never knows. I don't, and I'm absolutely shameless when it comes to trolling for input from y'all. *G* Insight from input can come from anywhere; IMHO it helps to get out and cast about in 'other waters' to see what happens.

...and it passes the time...*G*
Map, glad all is well, and congrats on the 25th sir! I still enjoy the pics of your Ohms, especially the pair in F cabinets. Always liked those! Glad too that your Bel Cantos are doing such a sterling job for you as well.

Jerry, yes I am certainly aware of the "Walsh Affliction", it catches some of us often.
FWIW their was a DIY room at the last audio show I went to (no Walsh speakers unfortunately) and I came away thinking how silly the DIYers sound made many very expensive offerings there seem. I'm surprised but happy they were allowed there. The DIY stuff hit way above what one might expect but was certainly not pretty. Lots of pretty impressive looking gear as a whole there though.

The thing I like about Audiogon is that it sets a high standard for home music and sound quality. Where it becomes interesting then is all the different recipes out there for good sound at all price points.
Fraz, the one significant enhancement with my OHMs recently was placing the 100s in my family room on Aurelax Subdude platforms to minimize interaction with the suspended plywood wood floors under the carpet there. That totally transformed the sound in that room by getting bass interactions with the floor under control. Inexpensive and definitely worth a try when called for.

My big F5s sit on solid concrete foundation. The 100s upstairs now sound more like those I have set up fairly optimally downstairs.
Map, that's the 'problem', IM not so HO...the Walsh concept/approach is almost in stasis, except for the German Physiks units. Although I've not been fortunate to hear any of them, the methodology appeals to me...

(I try not to 'rant & rave', but you'll pardon me if I edge into that territory...*shrug*)

I've decided what & where I want to take my 'little project', in my odd sort of fashion.

A 3 way Walsh 'stack' has a certain 'bent appeal' to me. I realize that this might offend the 'full range F' folks (sorry, Map *G*), but it just might have 'legs'.

Start with a carbon fiber 'woofer' at the bottom.
The 'mid' (in the middle, natch) with an aluminum cone, lighter than what I'm currently using (2 mil vs. 5).
The 'tweet' up top with titanium foil.
All drivers selected for high heat resistance and capable of handling serious wattage. No more voice coil frying, no. And, loud is fun now and again...
(No wrinkles in the bass cone, either.)
The surrounds of a sorbotane/EVA laminate. The sorb on top with the EVA (which in my experience is stiffer and can hold the other up) underneath in plane.
I'll stay with the PVC for structure. Strong and has its' own absorption characteristics. Sheet stock available in black, but it likes paint for the tube stock.
I want to try to avoid 'mystery materials' on the cone interiors as much as possible, as it seems to me to be problematic in the long run. But I'll be happy to be proven wrong if that's what goes down.
Active EQ, obviously.

You heard it here, first. *G*

Lets' see how many iterations/'v.X' I get to slog through... ;)
Interesting Map, that is one thing I really didn't mess much with was base platforms when I had my Ohms, just goes to show you, one never knows what affects these seemingly simple things will have.

With my Larsen Model 4's, I do have them sitting atop Base isolation platforms from the UK, and then a set of four SD footers between the Base platform and bottom of the speaker cabinets. Seems to work a treat. I am on a slab with laminate wood flooring, which can be an interesting thing to deal with at times, depending on speaker. My Obelisks seem more screwed up n the bass end on this floor. Something I still haven't totally worked out but getting there!
...but I also intend to continue making the smaller (6") units better as well. I like the size of the 2 pairs I've currently got running, and they'd benefit from better drivers/cones/surrounds. That, and a tweet on top. Set up with a sub and they're pretty sweet now (if I ignore some obvious resonance issues for the time being), and the breed could only improve....

Besides...when you run 2 pairs of them in a surround fashion, even with just L&R channels (as I'm doing), 'interesting' things happen acoustically. Things 'localize' themselves 'where' on might not normally expect...and stay put...

Cheap thrills *L* perhaps, but it amuses me enough to continue pursuing that effect as a 'side experiment'. I've touched on that subject elsewhere as to what I've got in mind with that....
In any case...

I'm going to be busy with Real Life Concerns (like making a living and supporting my cheap thrills), so my little projects are on hold for a time. I'll look in periodically to keep the cobwebs cleared off.

Take care out there. People like me on the highway. ;)
After 8 weeks in Raleigh...nice hotel, but traffic/smog/installation work tends to fry my little brain. But good product, happy client and $ is always a plus. And I can get back to my 'little obsession'...

Back to the 3 way v.4 as time permits...
...a long threatened 'experiment' comes to fruition...

Just some particleboard scrap utilized to create a vertically aligned pair of drivers; not elegant but suitable. A pair of units, the top with it's cone base connected with a 'sleeve' to a second, upside down. Base to base, to see what would occur.

It's just as I thought....there is no noticeable negative effect with regards to gross cancellations of response, at least in a listening test. If anything, volume/spl seems to be augmented...which IMHO relates as to why GP 'pairs' their DDD units and indicates such in their specs.
Because of the difference in size of the cones of my drivers, there seems to be an 'evening out' of the tonality, much like what we'd experience with different driver sizes with a conventional speaker. If there's anything going on that's perhaps not apparent without 'getting deep', there may be the condition of the cones moving towards each other in the lower frequencies being cancelled out. If the seal between the two was airtight (which it certainly isn't now), any tendency to 'push air' as with a conventional driver might be damped out. Just thinking...

If there's anything noticeable that's a negative, the spatial qualities at the intersection/collar at the bases create a 'null zone' in the near field, say 1~4'. Not surprising, that. The radiation pattern tends to be tilted 'up' from the cones, more or less at a right angle from the cone's angle.

...but fun to play with, none the less....*G*

Next variant: Mount the units reversed from as shown, but spaced apart vertically...think of the lower unit above the upper one, but say 3~4' apart.

Will the created dispersions 'blend' better, much like the interaction of the T/M/W of a conventional speaker? My experience with my little clones says they will....stay tuned.
If interested in what the above looks like IRL...
BTB, since this thread seems to be pretty dead...

If you've any interest in what I'm doing currently, you might follow the address above. There's more activity there, both from yours truly and from other parties interested in diy Walsh drivers. In my limited way and means I intend to continue my effort to improve upon my 'little clones'. You're more than welcome to join in or merely watch what occurs.
Regard, Asvjerry, aka jerryrigged, jerryasv
Anyway, if you've made it to this point, this is what I've been enjoying sounds like:

These are V.3's with an 'Infinity' styled tweeter.  V.4 is under development...they'll look similar, but better 'under the hood' if all goes as planned and desired.
V.4 project is still underway.  Support 'rings' need to be CNC'd, some hardware to acquire...then assembly routines to perform for 4 units.
Upper drivers for the V.4's partially completed and tested.  Wonders never cease, they work AND pretty much as intended.  Having 4 units 'act' the same, at least to one's ears, I'll chalk up to spending a certain amount of time 'building between my ears''s less annoying to screw up a daydream. *G*
Real Life concerns (large out of state project that'll occupy moi' until Dec./Jan.) will put the project back on the shelf until that dust settles.
It'd be nice if AG would allow posting pics, but one can't have everything.  But when the deed is done, I'll post an improved YT vid...with better audio, too....