I need to mount a center speaker under a tv which is mounted on a stone fireplace. Since it is made of stone the surface is not flat so I am not real sure on the best way.
weight is 10lbs
5-7/8H x 14-7/8W x 6-7/8D
I'd find an appropriately sized board and mount it directly on the stone using angle brackets and epoxy putty. Paint or stain the board as you like.
When you've located exactly where to mount the brackets, drill holes into the stone or mortar using a masonry bit. Make the holes a good bit larger in diameter than the screw threads so you can easily fill them with the epoxy putty. When completely cured, drill holes in the epoxy to fit the threads of the screws. This will be strong enough to hold much heavier weight than your speaker.
I have a flagpole holder mounted outside my house on a brick wall. Wind would always tear out the screws holding the mount whenever I had the flag & pole in place. I tried many other methods of attaching it, and all of them failed until I used epoxy putty.
