Channels 1-2 offer combo XLR-1/4" mic/line connections and a Hi-Z switch (for guitar and bass), while channels 3-4 offer XLR or 1/4" inputs. Channels 1-4 include inserts, and single-knob compression. Channels 5/6, 7/8, 9/10 offer two 1/4" inputs, while channel 11/12 uses a 3.5mm stereo input. Channels 1-10 feature gain controls, a 3-band EQ, an aux (monitor) send, a dedicated FX send, pan, mute, and level faders. Engaging channel 11/12's USB 3-4 switch will override the 3.5mm input and enable the USB return from a computer.

Each channel strip includes button selectors for Main L/R, Sub 1/2, and Solo (PFL). The master section offers dedicated faders for Main, Sub, and FX. Main output connectors include both XLR and 1/4", while sub and control room outputs use 1/4" connector. A dedicated 1/4" TRS headphone output includes its own independent level control. Other features include an input / USB 1-2 blend control, a dedicated FX output, an FX level fader, and an FX mute, which can also be controlled via the 1/4" footswitch input.

The ProFX12v3 features a download for ProTools I First software and The Musician's Collection plug-in package including 23 high-quality plugins with BBD Delay, Level Lite, 304E EQ, and 304C Compressor. You also get Tracktion's Waveform OEM and the DAW Essentials Collection. To authorize the software, simply input the mixer's serial number into the website. The Mackie ProFX10v3 includes a USB cable and power supply.