16Input 2/2-Bus Mixer The X1222USB provides six mono mic inputs, two of which may also be used for stereo line-level devices, such as keyboards or sound modules. It also features channel Inserts for inputs 1-4, a stereo 7-band graphic EQ, which can be assigned to the main or monitor buses, and the proprietary FBQ Feedback Detection System. Other features include XPQ 3D stereo surround effect and Voice Canceller function for removing vocals from prerecorded tapes and CDs.