re: #6 Charles Johnson

It’s to prevent the drums from leaking into the other microphones as much as possible. The ideal situation in a professional recording is when each instrument and/or vocal is totally isolated on its own track, with no other instruments audible on that track.

I’ve been on many sessions where the drummer is in a separate sound-proofed room, or is surrounded by plexiglass sound barriers.

Of course, sometimes a band wants that sound where everything is mixed together and they play live in the studio without any attempt at separation. But most of the time the engineer is much happier when everything is isolated.

I’ve been on both sides of a Plexiglas fishbowl. It’s totally weird to play in that environment, but I suppose for a professional who is adjusted to hearing his drums play in his in-ear sound system, it probably doesn’t make much difference. For mixing, though, it’s so much easier to manage if the drums are tamed.