The Si Expression 3 is a 32-channel digital mixer. It features 32 recallable mic preamps plus 4 line inputs, 4 internal stereo FX returns, AES in, and a 64x64 expansion slot offering more than enough scope to use every one of the 66 input processing channels. Every input processing channel has dedicated processing for high pass filter, input delay, gate, compressor, and four band EQ whilst keeping it under control is a comprehensive automation system augmented with four mute groups and FaderGlow™ to light the way so you are never lost.