The Allen & Heath Qu-SB is a digital mixer with 18 analogue inputs and 14 outputs. The Qu-SB is as portable as a stage box, expandable to 32 X 24 I/O, and is controlled from an iPad! Excellent and intelligent audio solution for live bands, AV applications, theatres and installations. You can also track 18 channels simultaneously directly to a USB flash drive, via the USB port on the back panel. The Qu-SB allows for up to 11 monitor mixes.