Here’s a Blu Glo Home Media solution for the common problem with TV mounts over a fireplace.
We have installed this mantle mount several times in residential homes. It is an articulating mount that drops the TV from 18 to 24 inches lower than when it is parked. The designers also included a bracket for a sound bar.
In this particular case, it is a Sonos Arc sound bar. there are several design issues to take into consideration, but this may be a good solution for your home!