I have done Cats idea with removing baseboard before for friends. He is correct when he says it must be done very carefully. Also, be prepared to touch up the paint to restore a perfect look. You can also get up around doors by removing trim. Then fish up to where your wall outlet will be for the speaker wire protrusion.
I will never cut into drywall because seam filling is my most hated activity EVER but it gets your speaker wire anywhere it needs to go invisibly once it is re-seamed and painted.
