"As I recall they had great hopes for the mushrooms ... but at the end of the day they didn't do the job as well as had been expected ,and the acoustics were still crap after all that work and effort"

I was in the minus years when the fiberglass mushrooms were added but with the knowledge of singing in lots of places where I want to hear the reverberation of my voice I could imagine that without them the resound would be horrendous.

The problem is that the hall is an oval shaped building with 2 bowls facing each other. The sound energy is bound to reflect and hit itself several times creating unwanted effects. Cast iron is not an acoustically sympathetic material as anyone with a bath would tell you, that said if the note is sympathetic to the cast iron shape it resonates beautifully (which isn't useful with lots of notes!)

I don't think volume is too much of an issue... if you were in the RAH on the Sunday afternoon or if you check out the recording you can hear a baby make a noise, surely a folk singer can sing higher than a baby?

That's enough of me chattin sh*te lol...

Am fascinated to find out what solution they are bound to come up with... it'll probably be a combination of sound deadening material and sound canceling technology combined with amplification (not very folkie but then the RAH wasn't designed for folk and folk was really designed for public houses and family homes.)

:D