Have you heard the Helios? Hard to call it superlative without some subjective experience and honestly some real Klipple testing.
I have dabbled in interest in that speaker myself but that is a big commitment for something you will never be able to 'return'.
I am a DIY hobbyist. I have definitely built stuff I didn't truly love, including some expensive kits.
I have mad respect for Jeff Bagby(RIP) however the one speaker I made of his was not exactly what I would want now and did not measure all that well. (The PartsExpress Tango) I was able to drop the passive crossover and turn them into actives that measured and sounded much better. Now, I am using the drivers, enclosure and parts in various other projects so the $$investment still has legs and fun times.
That said, the risk of not liking the speakers is real.
How much should the screws cost? I say this light heartedly but really it has truth to me.
Parts are parts. As I am sure many realize, a person can make superb speakers with lower cost parts and bad speakers with expensive parts.
Keep in mind as well that many DIY speakers and parts are now retail/commercial products. With all the marketing and 'design' trappings in play. Some of the best design choices for DIY are still the most pedestrian.(look at the BMR, nice basic SB acoustics woofers and a very inexpensive midrange from the OEM market. Pricey tweeter though.)
Overkill bracing and more expensive crossover parts is not exactly representative of excellence or a guarantee of performance. Nor is changing active crossovers 'on the fly', each change really has to be considered & tested/explored - it is clearly faster than passive parts but it is still a process not to be underestimated.
Manufacturers in 2023 can engineer extremely good quality parts for crazy low prices and often some of these parts will appear cheesy in the hand, but are in fact quite well engineered(and vice versa with very beefy parts sometimes just being average performers despite $$). You simply can't judge a book by its cover.
Many large scale manufacturers can make extremely high performance parts at very low costs, even if ordering them outsourced from an OEM. Because it is 2023 and computer modding and other engineering tools are so powerful a very pedestrian looking driver may in fact be superbly engineered yet cost very little $$ to make. Even high value items like stamped steel baskets and even plastic baskets can outperform cast baskets of old.
In any case what a DIY buyer pays for the same performance in a driver that a large manufacturer pays is sometimes very far apart - as in I might pay $75-200 for a woofer of the same performance quality that costs JBL or KEF $10-20.
All that said I do advocate for DIY as the best way to learn and for the right person is it fun - truly something worthwhile to do. At the higher end of DIY you can save money as well.(I don't think you can save much money anymore with entry and mid level DIY project vs 'top of price class retail-when on sale prices')
If you make those Helios and feel crazy - send them in for a Klipple test. I am sure many would be curious. I know I am, they sure look like a possibly great speaker.
I may just do that; of course, I will measure them first. Part of me wants to build the speakers as a tribute to Jeff. He contributed greatly to DIY scene, and some of his freeware is quite sophisticated. Have I heard them--no. Would I like to before embarking on this mission--of course. I haven't checked all the sites, but Helios only comes up with two links--one to Meniscus Audio that sells the kits, and another to a FB page of one of the co-designers.
What leads me to believe its a solid design is Jeff's musings about the project. One he said it was his best design, and two that he had never heard a better two way. Given that he has likely heard thousands of 2 way monitors, that's quite the claim. And of course any designer is inclined to toot his own horn, but I don't think Jeff was given to hyperbole. For a friend, I have built another of his kits that use similar drivers--the Kairos which uses the 6.5" papyrus woofer and the SB 29 tweeter. What I found interesting (and Jeff and I conversed quite a bit about this--is when I tested an active version that involved cleaning up the impulse responses it was nearly indistinguishable from his passive implementation that was nearly phase perfect and used 1'st order XO's (mine were 16'th). I thought the active version would be noticeably superior. So there's that--implementing examples from the same driver line up (cost was about 750 IIRC). I plan on making mine active, but installing the passive xo's so that whoever gets them can plug and play without the need for 4 channels and the filter set to cleanup the IR.
So I'm chomping at the bit--I just don't see where I can go wrong. The only thing weird is using a 9" woofer and 1" tweeter. Here the waveguide allows crossing at 1300 Hz which would seem to be asking for trouble given the size difference, but he claimed the directivity behavior was superlative--there I think the Kipple would be very enlightening.
Are there better two ways? If so, I suspect that they cost a ton--one
speaker that uses Purifi woofers and the Satori Be tweeter (no wave guide) is priced at 6.3k/pair whch seems reasonable given the retail driver cost of $1600--Salk sound--speaking of direct sales.
Worst case the drivers end up in other projects--one that comes to mind is a floorstander using the Be tweeter, the Purifi 6.5" midrange (according to T. Graveson the finest midrange he has ever heard) in a small monitor sitting on large cabs with 10" or 12" woofers.
For the Helios I like this veneer, think I'll wrap the baffle in carbon fiber.