In message , A H
writes
Must be the same as/similar to the Royal Concert Hall in Glasgow, it is
directly above the Underground (Circle Line) and was built on rubber 'shoes'
to absorb the vibrations from trains passing underneath. I imagined the
Symphony Hall in Birmingham was the same, good to have it confirmed. Thanks
Ian.

You're welcome. I occasionally get to guide people through there and
have in the past even been lucky enough to go down into the "basement"
and see the insulation itself.

I'm ashamed to say that I've never been inside the Royal Concert Hall in
Glasgow. I hope it's at least as good as "ours"! ;-)
--
Ian Jelf, MITG, Birmingham, UK
Registered "Blue Badge" Tourist Guide for
London & the Heart of England
http://www.bluebadge.demon.co.uk