Any comments on BBC A2, A3, D2... Broadband absorbers??

Hello there! Ive been reading lots of papers from the BBC database and found some interesting ones on Broadband and low frequency absorbers. Some of them seem really simple to build for the performance they claim to have in those papers (even if its not that much, still good performance). Here i attach the links to the BBC articles i refer to: This is one of the most promising ones: http://downloads.bbc.co.uk/rd/pubs/reports/1992-11.pdf Here is more data on A series Broadband absorbers http://downloads.bbc.co.uk/rd/pubs/reports/1982-08.pdf Here are the building plans for them: (pp 113...) http://downloads.bbc.co.uk/rd/pubs/arch ... actice.pdf Any insight on the subject would be most appreciated!!

Aunty knows best....... The BBC papers spell out the principles and test results, I can't think of anything to add, but to commend them. This was the first and still IMO the best broadcaster. At a time their R&D had the budget of a small country. Their broadcasts from speech to music almost always sound impeccable. They have a few lesser known projects, e.g. https://www.bbc.co.uk/rd/publications/rdreport_1994_12 And the Controlled Image Dispersion Studio Control Room. And, afaik they invented Digital Audio......