Effects of different feet on floorstanders with a thickish rug


A concurrent thread asked for opinions on the effect of spikes and other foot treatments on floorstanding speakers with a hard, concrete underlaid floor -- what would the answer be with a moderately thick rug over plywood?  
128x128cheeg
Post removed 
If the objective is to completely pierce the thick carpet and the underlying mat in order to achieve better coupling with cones a hole punch comes in mighty handy.
Are you asking about a concrete floor with various things on top of it or are you comparing a concrete floor to a traditional joist and plywood floor?

@n80 -- no, the OTHER post I referred to was asking about a concrete floor. I have a traditional joist and plywood floor, with a moderately thick rug over it. I don't hear much difference when I use the spikes; what should I be listening for? Is it common for people with rugs to use their floorstanders without the spikes? If so, is there anything else I SHOULD be using for best sound?