The image above shows added insulation. High temperature caulking was applied to all fireplace gaps. Aluminum tape was used for some of the insulation joints. On either side of the image is partial images of recessed lights that are hanging because the ceiling still needs to be painted.
The two boxes on either side of the fireplace is for left and right surround (5.1) speakers. The center speaker will get its connection from one of the blue boxes above the fireplace.