It's a valid concern, but obviously Sound Rooms are not intended to distract from the Main forum. What they do is give some members the chance to start a focus group where like-minded like-interested can gab about, while not consuming the main forum with chatter. They can moderate it themselves as well, and carry on with their interest without having to deal with uninterested chatter. Another way to look at it is a place for things like CarverFest to live. Multiple topics can be created about the event, and even add dates to the Sound Room calendar and files and galleries all related to CarverFest. This also gives the coordinators of the Carverfest a place to set the agenda by having full moderation of the topics and membership, and create an atmosphere totally dedicated to their event.
I must clarify something about Sound Rooms:
Private Rooms, that is, Sounds Rooms that are hidden and members must be invited, are NOT ALLOWED.
My idea is more closely related to Sub-Forums, and not to be used as a tool to exclude people.