Which Tweeter preferred- dome natural material, Beryllium/Metal or Planar Ribbon? Why?

In mho....I have a pair of the full dipole ESS AMTs that sail away from anything else I've heard in terms of  what you can subject them to....

Get the xover right and pair them to whatever can 'keep up with them' in a space prep'd for dipoles.

Effortless.  And if you overdrive them, the element is replaceable...

(Always thought a line array of them would be scary....)

...but I'm just weird....*L*

@danager Well, Charlotte is but 2ish hours from me.  I suspect the dealer would take one look at me and accurately judge me a 'lookie Lou'.  So I'd have to talk extremely fast, rent a car that would require return Immediately if not sooner, dress beyond spouse's comprehension, and enter with some willowy blond that would also need to be....'rented'. *L*

But, agreed...I'd love to hear them as well.  It would spoil me worst than being staked out in the yard for a month after untimely demise (although some here would demand a stop-motion vid to verify that fate...). 

Meanwhile, the 30K$ is a bit of a pause...but being the sneaky SOB I can certainly aspire to....

ESS will sell you direct 18 of the large Heils' for $3,582 plus tax & shipping.
They're heavy, so the latter will be substantial.
Throw in the extra $18 and you can have 18 BT adapters and a choice of 2 versions of headphones....wipe out your gifting for years... ;)

They offer their 10" woofers for 149$ each....get as many as you think you could tolerate....the passive radiators for them are 110$ each, but to duplicate the Apollos'. not really required....

Crossovers...I'd go with some pro version.  I like my Behringer 2496 and you can tweak yourself into a puddle...*teehee*

OK, you're down about 5~6K$.

Cabs...Heils' are dipoles, and ESS doesn't 'cab' them....why should you?
I can suggest a line source frame that would make wood blush, but I'd go with aluminum.

Woofer cabs....Apollo's are lovely, but the design is ancient.  Personally I work in wood, so not an issue....for me, anyway.

Sweat equity in assembling something that'll crack sheetrock. *Evil G*

I've just saved you nearly 20K$.

I'll bill you later.  ;)

When would you like to begin?

Regards, J.

(ESS ought to give a discount on a 'bulk buy', but they've already discounted on them....Promise pics of the end product....;)...  The Heil AMT is too good to let fade into obscurity or bankruptcy...and NO, I'm not a dealer and I don't get a commission on anything.  I'm just a fan....)

Y’all could do so much better if you’d try....Really.

*kicks soapbox into the corner...

@arion ...Hi Mike, and I'll happily take you up on your kind offer..  At the minimum, I'll give you the shot at addicting me, and making @danager insanely jealous.... ;) 

As said here in AVL, "....it's like getting 2 birds stoned at once!" 
...but I know nothing about that sort of thing....🙄

We've an upcoming project in the TriCity area 2nd quarter this year, so that would be the likely time to Not show up in or with any form of 'rented'  device or organism.

I'll be nice, so you ought not to have me see anything that would require a NTC agreement or the like. (I'd sign one if requested, however....know the routine...)

  And I fully appreciate 'keeping the lights on'; spouse and self have our own 'beast' to keep fed.  The results are in your area, PM for locations...and other perhaps interesting bits...

The Apollos' are impressive on the pages of your website, and I'm already concerned that they will live up to and beyond my wildest exhortations to my spouse....who would have me talking soprano for bringing them home.

"Are you Insane?!  ...oh, right...that already existed....*grumble*damn*

Thanks again, and back to...

@andy2 ,,,Heils' sound Horrible by themselves....a heavy lump of 'squeeky', it's true.  If you didn't know beforehand what they Can do, you wouldn't buy them either.  But that's the case of any tweeter singing solo.... ;)

@danager that is true, 800ish is a more comfy zone to start the cross.  You can push them near 500, but they're not happy about it....
I've a pair of Polk 6" with a passive that fills that gap 'twixt Heil and woofs...with a sub for 100 and below....

Would ultimately do the same for a Heil line source. which could make my 'fever dream' above more practical in reality...

...whatever That is...open to interpretation as usual, esp. in sounds audio. 

Ever been 'smote by a Greek god'? *L* 

Not quite the same as:
"SMOTE (synthetic minority oversampling technique) is one of the most commonly used oversampling methods to solve the imbalance problem."

...but it does cause a pause for one...;)

'The walls have eyes and ears.....'  👀 *ghostly racket*L*

@cakyol , precisely...I'm obviously addicted to amts'...horns are edgy and  'in your face', domes one step behind if metal (paper?; see 'cones'), cones sound 'stretched' at high levels...

Other 'exotica' I've not been exposed to...plasma could be a 'contender' if they didn't purport to suck the air out of the room...(I like air...use it a lot...)

'Stats are ok. but have the 'Maggie Issue'...the larger ones' make me feel like I'm in the first segment of 2001, the smaller (spouses' pref) seem 'leashed' and restrained....

"Call me...irresponsible..." or just a crank.... (I'm ok with the latter...)