Pads or Spikes?

I agree with the decouple/pads approach suggested by others here and I have had good luck with damped springs, such as sold by Townshend.  If you want to try it without spending a lot you could consider an elastomer solution (basically another type of damped spring) or a less expensive spring solution like this or this to get started.

This is definitely one of those areas where the best advice is "do something" and "see how it sounds and looks" and then move on. Every little bit helps, but you have to live with it and try to get back to other aspects of the system or just the music, itself.

Years ago our living room was on a ground level concrete slab. Spiked feet on my heavy speakers worked great. My current living room is a suspended frame floor with carpeted sheathing.... the same spikes on the same speakers just exaggerated the resonance of the floor, and bass was boomy and ill-defined. Spring pucks worked much better in that situation. YMMV. As @hilde45 says, "do something" and see....

Leave original component footers in place. Put lead bricks (with self-stick vinyl bumpers attached) atop components. This is by far the most silent option I have tried.