OSD''s SSVC2 is a space-saving companion for your stereo or multi-room audio system. It has connections for two pairs of speakers, each with independent volume controls. Dual source inputs let you connect two amplifiers. Each amplifier can play through a single set of speakers, or you can have the same amp playing across all connected speakers. The built-in impedance matching circuitry is useful if you have a few speakers wired up that present too low of an impedance for your amplifier. It helps magnify the impedance to keep your amp from overheating or shutting down.