My experience with plaster walls is that they are quite sound-deadening. I don't think you'd get good sound *through* the walls.
We have brought our wire up through the basement, through little holes in the corner of the floor.
We have little Bose speakers tucked in corners, on the shelf or attached to bookshelves. The larger bass speakers are under the kitchen table, on the bottom shelf and tucked behind the love seat.
We chose black for 2 of the sets of speakers because that practically disappears. Because I needed little white speakers in the kitchen, we painted the bass speaker with a "Hammered Bronze" spray paint by Rustoleum. This one is tucked under the kitchen table and is invisible from any walking/working level.
Carolyn
It's the TV *I* want to get rid of