For me, a fireplace mantel is at least as stable as one of those Target wall shelves and likely to be much more so. Plus, it is anchored into the chimney, the most structurally rigid part of most houses, certainly more rigid than a typical stud, even if the latter is weight bearing as it should be. So, I have to ask why you think a mantelpiece might vibrate, unless the whole house is vibrating, which can occur, if you live near a major highway or if you live under an airport approach pattern, but which is usually a very transient phenomenon? Apart from that, there is nothing wrong with doing your recommended glass of water test; that would detect constant local vibration. I just can't understand why that would happen, and if it does happen, there is likely to be no sanctified vibration-free location in the entire house.
Placing turntable on top of fireplace mantle?
My room doesn't have a ton of space, my fireplace mantle is very solid and stable, and it does not get hot to the touch (have tested this already)
Any negatives to placing it here? Previously I was using a wall shelf, (pictured in the second and third pictures), but placing it on the mantle would take up even less space in the room. Just wondering if I will have any additional vibrations which could cause reduction in sound quality by using the mantle instead of my old wall shelf.
See pictures (note I just moved so things are a mess and not set up yet):
https://imgur.com/a/x2Jhf1Z
Any negatives to placing it here? Previously I was using a wall shelf, (pictured in the second and third pictures), but placing it on the mantle would take up even less space in the room. Just wondering if I will have any additional vibrations which could cause reduction in sound quality by using the mantle instead of my old wall shelf.
See pictures (note I just moved so things are a mess and not set up yet):
https://imgur.com/a/x2Jhf1Z