I was in the Store of Knowledge(PBS) at the mall and found an elastic hollow ball full of little soft balls meant as a toy to squeeze. $5 got me the ball full of balls and I have used them under the feet of some of my gear to isolate it from vibrations in the shelves. To really test this out I dragged out an old Sony CD player that would skip from big bass at high volume. It worked fine. For the less than the price of 1 isopod foot you can get enough to isolate 4 pieces of gear.