The trouble with mounting speakers inside your house is that there are few places to put them where they will blend in well. In fact, it would be extremely difficult to find a spot for them at all where they were to remain unnoticed. The best option is to actually design the room around the set of speakers rather than the other way around. It’s actually so simple when you think about it. You dedicate one room to studio and music production – where any amount of ungodly speakers and wires can be strewn about without any worry of making the house look bad. If this is not idea (and I’m betting it isn’t), the next best option is to design the speakers around the room.
If you have most of your gear in a more open living space, why not try a cleverer placement of the speakers instead? The idea that only large speakers are capable of big sound is fallacious at best, and there are currently many options that will allow big sound to come from a small package. Ceiling speakers aren’t a bad alternative since they fit flush with the wall and do not need to protrude more than what is necessary.