Is it possible to output USB audio from 2 iPads to a single USB-B port?
Is it possible to output USB audio from 2 pads to a single USB-B port (on a Midas M-32 mixer or similar)
[Re-Titled by Moderator]
iPad Pro, iPadOS 16
No. Your mixer's USB Type-B port can only connect to a single controlling device.
USB accessories with USB Type-B connections (or a cable with a USB Type-A connector) require connection to a host device with a USB Controller / USB Root Hub. This will typically be a computer (or other device) with either a USB Type-A or USB-C port.