Every piece of audio equipment is sensitive to vibrations, because most of the components act as a sort of microphone (called microphonics). Tubes are much worse than solid state, but even capacitors act as microphones.
Perhaps you can only appreciate these differences on a high-end system, but they are there.
Years ago, one of my friends made a very popular product by buying an off-the-shelf CD player and adding a 5 pound piece of plate steel to its insides and a new faceplate. While I scoffed at the nature of the modification and gagged on the price difference being charged, the plain fact of the matter was it sounded very much better than the stock player.
We could eliminate this problem in our high-end systems by placing the equipment in another room isolated from our speakers; but that isn't practical.
There are many fine isolation products on the market. Some appear to be a fine brand of snake oil, but at their core, they all strive to do the same thing: lower vibrations generated by your loudspeakers.
Pay attention to the vibes.
