Radio / Livestudio Combo pt2: Acoustics

Egan's studio build is surely inspiring. It's one of the builds I always go back to when I'm in doubt. When I say "chatting with someone" I don't mean a used car salesman. :) Just didn't think the name would make the difference. I myself might not be anyway near an authority on acoustics, but I can spot sh*t when someone's full of it. 8) I'm aware that the flush mounting system, built from mainly wood and fibreglass, is a much supported concept here on our beloved forum. Still, gathering input from different sources makes for a more thorough insight. Hence, I decided to raise the question: What exactly does a flush mounting system require in order to be utmost effective? Criteria I gathered from surfing this forum: 1) baffle should be 'flush' with the speaker's front 2) preferably 500mm of free space behind the speaker for absorptive materials 3) decoupling between the speaker and the rest of the structure 4) Baffle size should be about 3x woofer diameter in every direction The man I spoke to suggested that the wall corner behind the speaker should be of large mass. Preferably, the whole 'casing' of the speaker should be solid for optimal performance of the 'flush mounting' system. Is this in any way true?

the criteria sounds close enough. the baffle system itself though can be tricky because one aspect to consider is what happens when the baffle ends and the low frequencies wrap around it? having a solid mass behind it means reflections which mean phase and resonance related issues. or, you need enough absorption to avoid it. so from a sound isolation standpoint, you probably need the mass etc, behind it and from a treatment standpoint you still need bass trapping since the baffle ends at some point (infinite baffle is really just a trademark :-))