Lol . . You guys are a trip!
I have a concrete slab with foam pad and medium pile carpet over it. When I got my towers speakers, I tried them with just the tiny rubbery-button feet they came with, but the speakers would be too easy to tip and fall over. So I put on the spikes and they are more stable now.
I don’t know a final position for each item yet, so the two subs with rubber feet . . one sits on the carpet, and there isn’t space on the floor for the other sub, so it is sitting on a folded towel (to prevent scratching it) about 16 inches up from the floor on a brick shelf that is part of the fireplace.
I have no idea what I’m doing but hope to move things around once my roommate leaves (delayed by COVID-19) and I can swap the smaller furniture (in his TV room) into my listening room, which currently has a large sectional taking up a lot of room. Then I can consider room treatments. We all got problems.