These really work to isolate your sub. My Plans have changed and have a couple of these I'm not using. As new condition with the original box. $35 each shipped!! Amazing - Use It For Your Sub! The SubDude Sound Isolation Riser is an incredibly effective device that's used to float a subwoofer and yields nearly total acoustic sound isolation, resulting in a purity of tone that has to be heard to be believed! Subdude is constructed of road-ready (yet visually appealing) carpet, Studiofoam Wedges (underneath) and PlatFoam (underneath).