Back in the day, Rick made "pucks" to place under our equipment and called them "Rizers". Some were solid and used to lift the equipment up to allow better airflow, others were filled with sorbothane to help absorb shock under equipment. They came in a couple of thickness' or height. I have many rizers and they are under most of my equipment.
They are the silver pucks under my 275's and under the Cinema Grand in the pics.