If you are on the ground floor, and there is a crawl space below your listening area, you may want to try reinforcing the floor joists directly under your turntable stand using blocks and wood shims between the bottom of the joists and the ground. This worked well for my LP12 in one off-grade house where I used to live.
A wall-mount may not work very well on an interior wall since interior wall frames are simply nailed to the sub-floor with no building foundation directly below as is the case with exterior walls.
A wall-mount may not work very well on an interior wall since interior wall frames are simply nailed to the sub-floor with no building foundation directly below as is the case with exterior walls.