hey fmason-that looks like our sanctuary!! seats about 300,and it's ALL brick!!! about 100'x60'x30' with an arched ceiling -don't know what it's made of.i on't even have a B(yet) running my VOCE module thru a roland keyboard amp.If the sound man gets crazy with the house volume,sometimes we play together,sometimes we play with the echo(1-2 secs) VERYYYYYYY INTERESTING as the guy on laugh-in used to say (one of those 70' shows)