he SSA-4004 provides 6 x 4 distributed audio along with control, all in one compact 1U rack-mountable design.  The SSA-4004 offers 4 zones of high-performance pre-amplification, including independent control of volume, balance, bass and treble along with a 7-band equalizer (EQ).
Advanced 4-zone distributed audio solution for residential and commercial markets
Stereo preamp processing including independent control of volume, balance, bass, treble, mono and mute
Provides 4 analog and 2 digital inputs (TosLink)
Independent control of volume, balance, bass and treble; mono and mute; 7-band EQ
Integrated Controller with 11 control ports including serial, IR and GPIO