Maybe, if the speaker grills are flush with the opening so the sound is not restricted in any way. I would not put them in something that causes the sound to be restricted at all. Mine are sitting unencumbered on tables beside the couch. I think they look fine. Even my wife is OK with them.
Sorry I just read what I typed and meant the receivers. I am looking to mount these higher up on a wall and see just the speaker itself. I have full access to the backside of this wall and was hoping to hide the receivers and cords as long as performance wouldn't be drastically impacted.