The Bass Shaker products allow you to experience every thump, thrust and shake...the way bass sound was originally intended. Mount the bass shaker firmly onto the object or furniture you want to vibrate. It must be mounted to something solid, like wood. The bass shaker produces a vibration at about 40Hz. Wire two together in series for an 8 ohm load or use a single at 4 ohm. Does not require a crossover. Only a 50 to 100 watt amplifier is needed to power it. Higher wattage is okay of course. Connecting two in parallel is a 2 ohm load, too low for most amplifiers. Here is how you add bass shakers to your home theater system: 1) Find the variable low-level RCA output for the subwoofer (LFE) channel on the rear panel of your AV receiver and disconnect the cable going to your powered subwoofer. 2) Connect a RCA Y-cable to the subwoofer output on your receiver. 3) Connect the cable from your subwoofer to one end of the Y-cable. 4) Connect a cable to the remaining unused end of the Y-cable to an input on the amplifier being used to power the shakers. 5) Connect the shakers to the output of the amplifier. 6) Set the relative level of the shakers by adjusting the volume control on the amplifier driving them.