Mapman makes a very good point. Use a platform that is designed to absorb vibrations and turn that energy into heat. Avoid carpet piercing sharp-pointed feet that couple the speaker to the floor. This causes the floor, particularly if it is a suspended wood floor, to become a giant sounding board.
I also like the suggestion for trying an LS3/5a speaker. There are several current models, by different manufacturers that try to get a very similar sound to that old BBC classic design. I have not heard these so I don't know how well they manage to copy that sound. Not too long ago, I heard an original Rogers 15 ohm version and it sounded really good; it would make an excellent apartment speaker, although, ideally, it would not be place too close to the back wall.
I also like the suggestion for trying an LS3/5a speaker. There are several current models, by different manufacturers that try to get a very similar sound to that old BBC classic design. I have not heard these so I don't know how well they manage to copy that sound. Not too long ago, I heard an original Rogers 15 ohm version and it sounded really good; it would make an excellent apartment speaker, although, ideally, it would not be place too close to the back wall.