ha, did not know, I'm mostly DIY but will keep you in mind on my next project.
I built my sound room myself but with low tech, fiber insulation, double sheetrock, acoustic tiles, and a cork floor. It's about half the size I wanted, but my basement isn't that large since we have a walk up garage. I looked into doing it the right way and it was crazy expensive just in materials. My next place will have a proper dimensions as my electrostats are way over sized. One set are Apogees Hybrids and the other set are BG Radias, both have gone out of business after the burst of the internet bubble. My favorites are still the Coincident speakers which so good even without a sub. What products do you deal with? I've been kicking around the idea of a whole house system but using the existing amps and speakers to distribute from a bank or internet.