Has anyone heard or built an Axel Ridtahler (Ridtahler dipole) sub woofer?

rixthetrick... Happy 9/11...if that's even vaguely applicable to to wish upon us all....:(

No, I've not heard one IRL....but I've noticed the Tymphany LAT in my drilling about, and have considered a distributed sub array as an upgrade towards in the future...
That, and the means and methods of woodworking @ my fingertips with the drawings and specs within the 'jazzman' link you posted, caught my interest. 😊  I've a pair of 12" that have no particular pedigree but are available for fooling about with, the hardware noted in those plans, and the means of x-overing in all manner of fashions.

...pretty much consists of labor and MDF...even the latter I have 'on the shelf', the former a matter of debate amongst my spouse and employees. *LOL*

It's been forever since I've listened to any servo LF items, and they were rare to begin with...the complexity of the approach at the time made them a real commitment to those interested....

The LAT reminded me of the ESS Transar I actually got to heard long ago and far away, back in SF at an audio show that didn't repeat itself despite what seemed a good attendance.  The tech didn't really live up to its' potential, which is mho of the early Ohm/Walsh omnis....dipole/omni fan that I am.
We're in a 'better era' for these means of approach, and the riploles intrigue me....ergo my thanks for the link..

What in particular do you enjoy about the LATs'?
Size, response, general 'fit' in your prefs?

Weather here in west NC is Brilliant today....Spring fever in the Fall, tra la lah....*L*

You have a good one as well, Jerry 👌

Jerry, I am presuming you've worked with MDF and know that inhaling the fine dust is very much questionable for ones health? I was told it's the adhesives used in it that is the problem, and I'd guess US MDF and good old Aussie MDF are pretty much the same animal. Use a mask, I know by now, I'm used to wearing one (yes, a quip).

The LAT I used in my (almost dread saying it in here, eyes will roll) car. Yes I used a Tymphany LAT in my car's trunk (boot) and I liked that it went down pretty low without vibrating the frame of the car and muddying up what sound quality I could squeeze out of perhaps the worst listening room environment - a glass and metal cabin of a car.

There are those who have used them in stereo systems in listening rooms and there must be reasons why they are not longer manufactured and sold. I am aware of some of those reasons, and I will tell you that they are not a small enclosure solution if you want to get the most out of them.

IB Infinite Baffle, which in a car is a great option if you seal off behind the seats and use the whole trunk. And so they have been overtaken for small enclosure design by other drivers, unfortunately this is not well known.

It is because of the LAT I chose to build my single sub as an opposed twin driver setup, the drivers negate vibrations in the cabinet to some extent.

*G*  Good morning to you in the Down Under....;)

Yeah, hip to MDF...routes like butter, can be finished to whatever ones' predilections desire (lacquer finishes, anyone?), and will ruin your lungs if your 'inhaled distractions' haven't...
Masking is SOP here in the States for those with any rational amount of synapse in contact with each other, so my comments on unsocial distancing elsewhere are in force.  My use of thinners and myriad other 'non-entertaining' Rx for an aortic valve & pacemaker require (nay, Demand) I do so unless alone with my dog & cats (2)....
Spouse is currently on a jobsite, so considering wearing one when we get about to doing 'the Wild Thang' is a potential, but kinda gets in the way of the mood, but...*shrug*...whatya say...*L*

A Tymphany in the trunk was my understanding of their app, so no surprise there, and no 'eye rolls', either.  I'd thought of 4 in a distributed system in a listening space, but since they're N/A anymore...*tsk*
No induced rattling must be nice....I've thought that 'bassers' here, rattling all the hardware in their 'rides', ought to be in a routine of re-torquing all the bolts 'n screws within, less the vehicle exhibit an URD (Unplanned Rapid Disassembly) at the intersections...

"HEY!  Your driveshaft just fell off!"  Embarrassing, that....since most are RWD....and most sub arrays are in the boot..trunk....'back there'....;) *L*

The 'practical engineer' in me thinks the T-LATs' were victims of a complex design (referring back to the ESS Transar...neat to stare at, an 'interesting listen', but the mass & weight of the parts linking the bits?🙄...), but 'user enthusiasm' may have made a big impression with the warranty dept. and the reviews....  You 'may' be more conservative in the use of your LAT....

I suspect your interest in servo-drives for larger arrays may stem from that...educate my impression if astray....*G*

I wonder if there is any 'induced delay' in a servo setup....when we discuss fractional time 'loops' in a system that 'self corrects' IRT even  if driven by a digital app, on-board or not.  AG is a hotbed for those who hear the footsteps of mosquitos on the violins' bridge in a quiet passage.

I'm joking and teasing....'gimme' a break, Jake'. ;)

Smear in a bass line, esp. with a bass viola would seem a concern; not my current 'fare', but Understood.  EDM/Synthophila is my 'fun distract', but I listen to nearly anything sans MOR C/W....whatever That is, around the US....'default FM', to be escaped from....*L*

*tag* You're 'It', Jerry.... 

"...that boy ain't nothin' but Trouble...."

Ha!
Yesterday I surprised the younger workmate who's been assigned to work with me, alas I haven't worked out why the boss is punishing him, but I bet the truth will come out some day.

I was playing music off my phone through the truck's stereo, notice I didn't say hifi system, and I asked him what he liked to listen to? EDM
I cranked up some Armin Van Buuren he was a little surprised, then I played some mash ups and Deadmau5 mashup was a winner. I asked him if he was surprised, and he was. We talked about EDM events we'd been to with Dutch artists and such.

Now I will say that I have EDM on my home server, but generally for listening I like acoustic instruments, but I play some Doof Doof every now and then.

My car system was all about SQ, full time alignment, fully active channel separation into amplifier channel into each driver. European brand components, all sitting in boxes from the move to the US.
So I've come up in the World, from Downunder to Down South (up north, stateside).

I don't own a vehicle, I have personal use of a 2020 GMC Sierra truck from work, it's got some bells and whistles, and no payments for me. Paying down the mortgage at the moment, trying to be a responsible adult, well it's a good cover.

I'm an automation tech, and yeah I hear you on latency during the process loop, but with 4ms cycles, I think modern logic controllers will have little issue with low frequency correction like sub woofers.
You'd have every right to tell it off if it didn't perform with honor, "just one job, you're given just one job!"

sans MOR C/W?

sans = without or not containing, right? The rest is lost in translation to me, I'm afraid.

'gimme' a break, Jake'. ;)

In Australia that translates to, I'm just joshing mate.

Oh, I'm more worried about the mossies and nats eating me after all this bloody rain, and during quiet parts in music I can hear them buzzing - and I don't claim dog like hearing prowess either. Well I hope it's the mossies buzzing, maybe I do have tinnitus?

*LOL*  OK, 'stateside' now....I've inferred your current residence in TX, is correct or no?  If so...Gawd, weather (or not), heat/humidity, and the way 'mericans act will not have mercy upon you.

...but you've likely figured that out by now....;)  Welcome to the US....and I do mean Us....*L*

As a 'native' (of SoCA, not of the 'originals'), I'm still an item of interest to the locals here in NC.  But usually when I 'interact' in some fashion socially predictable...

I'm not a Dr., but try to cause no harm....or much.....;)

Great, no vehicle pymts., just drive and smile the miles....👍

deadmau5, huh?

https://www.youtube.com/watch?v=joWKEX03wd0&list=RDShB_HI6F1f4&index=8

...happy that 'AV' like that wasn't around in the late '60s'~'70s'.... ;)

Now, paranoia infused stuff like nonoises' 
https://www.youtube.com/watch?v=04qPdGNA_KM

'One needs....balance...in what one exposes oneself to....'
Hard to do of late, but lets' ignore that sub-routine for now....maybe ever...

Latency isn't likely an issue for the bulk of us, but you're down with how 'some' react to that line of logic...."I can hear a pin drop impact!"

'K, kewl......me 2, if from an air gun, butt 1st..... (Of the pin....point 1st, negative response....)  Ow. ;)

MOR/CW= Middle Of Road/Country Western...MOR/Pop, and all the rest, you've no doubt been exposed by now.....

Yes, jus' joshin'...I do that a lot.  Audio for me is a 'hobby', a pleasant distract from the usual Life in the Big Sh*tty, although AVL isn't big...just of a size spouse 'n self can live with & within.... *S*

I prefer a high degree of 'flexibility' over sheer 'perfection' at this time, so component choices reflect that here.  No real stand-out items, but that which scratches my particular itch(es)....in a far from ideal space to do so.

...but, that's another story.  And, at my age, I've no short stories anymore.

Best dealt with over some form of 'adult enhancement' of 'legal means'....and....

No, I won't 'go there'....the moderators would have a field day....*L*

Happi Weak-end, J