The VCSI is a slider control 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 VCSIs, with one pair of 8 Ohm speakers per volume control, can be connected to a 4 Ohm capable amp as shown in the Multiple Speaker Pairs 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 VCSI 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. Simple, reliable, flexible. Turn up the fun with the VCSI Automatic Impedance Matching Volume Control by Beale Street Audio.