WOW, check out these BW Nautilus clone speakers.

I cant quite tell but, that looks like a Vifa Ring radiator tweeter, which is ultra-expensive. Along with Seas mid and woof. Very neat looking. I assume the math is a nightmare to get right on those enclosures.

there has to be a point where its no longer considered within the realm of DIY.

and its considered professionally manufactured.
Kinda like going from amateur to pro status...I think this guy has achieved that level...

To me the term DIY implies less than professional.

They look incredible. Who built them?