The VCRI is an rotary knob automatic impedance matching volume control. That means multiple volume controls and speaker pair can be connected to a single, appropriately powered amplifier. It also means there are no impedance tables, jumpers or switch settings to mess with. Let's say you want a simple, multiroom audio system where all speakers are playing the same thing and each room has a separate volume control. Up to six VCRIs, with one pair of 8 Ohm speakers per volume control, can be connected to a 4 Ohm capable amp as shown in the illustration...with no jumpers or switches to configure on the volume controls. For a slightly different application, up to 4 pair of 8 Ohm speakers can be connected in parallel to a single VCRI connected to a 2 Ohm capable amp. This allows you to have a multispeaker application in a large room or in several adjacent areas that are all controlled with a single controller...with no jumpers or switches to configure on the volume controls.