My listening room is on a sprung floor above a garage, and I have had great difficulty with vibrations/footfalls, etc... A tip someone gave me has worked wonders. I have everything, including a turntable, on a pretty heavy 2-foot tall, 5-foot long entertainment unit. I bought some spring-loaded bamboo drawer dividers ($17/pair) on Amazon and placed four of them against the entertainment center on one end, against the wall on the other. It has made a huge difference in isolating footfalls, and tightening up the sound of the system.