I have wall-to-wall carpet in my listening room, with stand mount speakers; I found a big difference, especially in the bass, between using spikes and not using them. I think there is a thick layer of concrete between floors of my apartment building.
Speakers on carpet over concrete
My system is current located in a partially finished basement. The floor is thick carpet over a thick pad on top of concrete. Does it affect performance of the speaker differently if spikes are used that pierce the carpet and pad, contacting the concrete below versus removing the spikes and having their "feet" resting on top of the carpet which is also a bit less stable? I'm sure I'm not the only one with a system installed on carpet over concrete. How are yours set up?