Cross posted from rec.audio.tech

I am toying with the idea of installing several sets of speakers around my
new house when I eventually move. What I would like to be able to do is
drive all the speakers from a single source and switch each room on/off as
required. I have seen some of the speaker switches on the market - is this
all I need or is there more. Also these switches seem to be just that
(switches). Is there anything available that will let me control the
*volume* on each set of speakers independently of the others ?

Thanks

Andrew