If you don't believe DIY is competitive spend some time at DIY Audio. That forum is a world wide audio engineering brain trust of the highest order. These guys have owned all the high end gear and moved on knowing they can build better for a lot less.

The Tang Band drivers in my DIY OB's sell for $500. Anyone care to guess what commercial speakers with drivers that costly might retail for? I recently saw a commercially made single driver bass reflex version with my Tang Bands selling for $15,000. Wish I could find the link.

The 10 inch Eminence drivers as used in all the Zu's retail for around $60 each yet most Zu's sell for thousands. I've been all through their cabs and inspite of their great sound there's no breakthrough technology in their simple well executed enclosure.

As I said before, speaker building is not the black art some would have you believe. It's a science with predictable outcomes. Math cad programs are now available for a few bucks that will specify the type and dimensions of an enclosure based upon driver specs. Commercial speaker designers use these same programs.