I only investigated products that were capable of sending Midi Control Change messages to toggle mutes or mute groups. This excluded many small Midi footswitches that can only send Program Change messages. I also excluded devices that did not have built-in DIN Midi outputs. Products designed for USB Midi could be used with USB/DIN Midi converters but that adds another box so it isn't an ideal solution.
One option is the MIDI Solutions Footswitch Controller. This is available in single, dual or eight-switch versions. All versions can be powered by the Midi output from an XAir or X32 mixer. The units can be programmed to send various Midi messages in response to inputs from simple momentary or latching footswitches. Programming is done with free software but does require the use of a USB/Midi interface or cable.
These controllers support a wide range of Midi messages. Those most useful with XAir/X32 mixers, are Control Change messages for toggling mute groups. The controllers can also send two different System Exclusive messages when a footswitch is toggled. This can be used to send XOSC commands to load Snapshots or Snippets for more complex switching requirements.
The single switch version works well for toggling one mute group - to disable FX sends while talking - or to switch between two Snapshots/Snippets. The larger models could be used for more complex switching.
The MeloAudio MIDI Commander is a much more comprehensive footswitch. Although primarily designed to control guitar processors, it provides two custom layers that can be programmed to generate Control Change and Program Change Midi messages in response to the various switches. This is a very well-constructed device that can be powered by two disposable or rechargeable AAA batteries or with a USB power supply. Programming is performed using the footswitches and OLED display.
The MIDI Commander can be used to control some XAIR/X32 functions but there are restrictions.
Each custom layer uses the same Midi channel for all the switches and optional expression pedal. Using Midi channel 2, this allows mute groups to be operated with Control Change messages and it can load X32 Snippets with Program Change but the expression input is not usable. It would not be able to load XAir Snapshots on the same layer as mute group controls.
When a switch is set to generate Control Change messages with a toggle, the on action sends value 127 and off sends 0. The nearby LED indicates when the switch is on. This can be confusing when used with an X32 - when switching a channel/bus mute, the LED indicates that the channel/bus is muted but when switching a mute group, the LED indicates that the group is unmuted.
When a switch is set to send a Program Change, the program number is determined by the bank switching so is not freely assignable. Sending a Program Change turns off the LEDs on Control Change switches so, although the actual mutes don't change, the footswitch no longer displays the current status.
There is no provision for setting the starting state of the switches. After switch-on, it is necessary to click any Control Change switches one or twice to synchronize the mixer and footswitch.
These restrictions reduce the functionality of the MIDI Commander as a controller for XAir/X32 mixers. It works well enough for controlling mutes and mute groups but the other functions are not really usable.
The Source Audio Soleman is a highly configurable footswitch. It only has four switches but their actions are individually programmable with a wide range of options. Up to 64 named panel layouts can be programmed. On each panel, the LCD displays the panel name and the user-defined three-character name of each switch. Panels can be selected by pressing two of the switches simultaneously - or with an optional external footswitch. The Soleman includes an input for an expression pedal and can be calibrated to suit most pedals. The unit can be powered with the included 9V power supply or via the USB port. I power mine with a USB power-bank so I don't need to run a mains cable. Programming is done over USB using the free editor software.
The actions of each of the four switches in a panel can be programmed with few restrictions. Each switch has a name, a default state, a latched/momentary/radio-button mode, an on action and an off action. The actions can be one of the commonly-used Midi messages on any channel and with any data values. Actions can also trigger macros - sequences of Midi messages. This is a very powerful feature that can be used to achieve complex switching. Macros can include System Exclusive messages so support XOSC commands. A simple example is to use macros so that a switch mutes one group and unmutes another - and the reverse when toggled. As the on and off actions are programmed individually, the meaning of the status LED can be set as required.
The Midi channel and controller for the expression pedal can be programmed for each panel layout. It is possible to set minimum and maximum controller values so an expression pedal could be used, for example, to operate a channel/bus fader between, say, -30dB and 0dB for gentle level control.
Setup macros can be defined for each panel layout. These will be run when the unit is turned on or a different panel is selected. These macros can be used to synchronize the mixer and footswitch so that the status LEDs reflect the actual mixer state.
The Soleman includes support for Midi Tap Tempo but not, unfortunately, in a way that works with XAir/X32. On these mixers, setting tempo over Midi requires calculating the delay time, constructing an OSC command to set the appropriate time parameter for the required FX slot, encoding the command as an XOSC hex string and sending it as a System Exclusive Midi message. This is so specialized that it is unlikely to be supported by any general-purpose Midi footswitch.
The Soleman is not a low-cost Midi footswitch but it has the flexibility to provide good control of XAir/X32 mixers over Midi in a small, well-constructed package. The only way to get better control would be to build one of the DIY designs that use OSC commands over a network connection.
This is a nice and very useful list for people who do not have the possibility/capability to use an arduino based system they can put together for just a few $ and program it to their exact needs.
It allows plug'n'play control of the mixer without having to understand midi or technical things
It connect via WiFi or ethernet cable and has a configuration web app where you basically drag n drop strips that correspond to a feature you want to control (for example sends/return of a bus, tempo of an FX, mute ...)
More information: https://footswitch.groupe-interval.fr
Hope this helps,