Adona platform shelves worked for me. Place the granite side face down on the carpet and rest the speakers on the MDF side. You can spike the speakers into the MDF if desired. Another benefit of this is that I can move my speakers very easily, no small task considering how heavy they are.
Speaker Bass
I have speakers that rest on carpet. I want to tighten up the bass. I have brass feet that do not penetrate the carpet. Should I get longer spikes or as a friend suggests isolate them from the floor? The carpet rests on wood under layment. There is a wife acceptance factor at work, too. All help is greatly appreciated.