It s not a problem of trusting or not trusting, the basic thing is this stuff, your stuff after the Ariel, is based on non obtainum parts, drivers, valves, transformers, and hipster theories on audio quality assessment...😕
Valves and transformers: this is a speaker forum & the OP has a speaker question.
Hipster theories? Which part - "flat response" or "low diffraction"?
Non obtainum? All of the speaker parts are obtainable:
The HF and midbass drivers are available from the usual suppliers.
The horn: go to the Azura website, place an order - the postage is pretty reasonable. Or get an equivalent from another manufacturer, such as Auto Tech. Or make / modify your own (this being the DIY forum).
The subs: current production, just place an order ... and wait. Or use equivalent units from a larger manufacturer.
My guess is that there's no need to get hung up on this exact combination of parts. For example, I really like the look of the FAITAL PRO LTH142. I imagine it could have it's mouth extended to result in a horn equivalent to a AH-425, but giving a slightly closer centre-to-centre spacing.
Note: the Beyond the Ariel was originally intended to be based on a coaxial. Lynn went off this because "every blessed one of them has the worst freq resp curves imaginable" (post 473). However:
a) The OP has access to newer drivers - the BTA thread is a decade old.
b) The OP says "DSP crossovers and EQ (room correction) with Rephase and Minisharc can be applied", whereas Lynn was frankly picky about parts, saying he wasn't willing to use DSP (except for bass) and "I find most electronics unlistenable" (post 1010). This difference in approach opens up options for the OP (and most people) that Lynn might reject.
If one was dreaming about the best of both worlds - a coaxial that incorporates a few BTA concepts - the RCF CX15N351 looks like a pretty good choice.
- visually, the RCF's horn looks like a truncated AH-425 (no rollback)
- the RCF also uses a 1.4" and a 15"
- the RCF also suits a 800Hz crossover
- high sensitivity
- decent freq resp curves (assuming a steep crossover and/or notch, to suppress the 2kHz breakup of the LF cone).