SPL SMC 7.1 Surround Monitor Controller + Expansion (Silver)  From SPL

Source Selection & Speaker Management

Two 7.1 and two stereo input sources can be connected to the SMC 7.1. This is important because in monitoring, two productions are always compared with each other.

A subwoofer can be added to a stereo input by activating the LFE button.

Each loudspeaker can be switched on and off individually, and the SMC 7.1 remembers the last speakers used for each source.

The Solo-In-Place function now turns the loudspeaker on/off switches into solo buttons. This allows each loudspeaker to be heard alone at its position.

Solo-To-Center places the selected loudspeaker on the center speaker, so that it can be listened to exactly from the front in case critical listening is required.

An alternative output is available for connecting a pair of stereo loudspeakers.

The 45mm all-aluminium rotary knob moves an 8-level potentiometer. 

Mute is especially important when the DAW is sending full-range audio garbage due to a problem. Mute can be used quickly to protect speakers and hearing.

As an alternative to the speakers, headphones can be used for monitoring. The headphones can be switched on and have their own volume control.