SPL SMC 7.1 Surround Monitor Controller + Expansion Rack (Black)The black SMC 7. 1 Surround Monitor Controller from SPL is an analog studio monitor controller for 7. 1 and stereo sources. Each of the two balanced 7. 1 inputs and the two balanced stereo inputs can be routed to the balanced 7. 1 output. The L R signals of the active input can optionally be routed to the alternative stereo output. With the high quality headphones amplifier, you can listen to the L R signal of the active input as well as to single