Behringer's X-Air range of digital mixers are a staple feature on stage in every bar and club gig. In addition to their many well documented features they include a guitar amp simulator which can be used in one of the FX unit slots.
While the built in Amp Sim isn't going to replace your real amps, and can't match the quality of a Helix or Kempler, having a couple of extra guitar amps on stage "for free", is a handy option as a backup, for a guest guitarist, a singer who chugs a few chords in one song, or just for when you're rehersing or traveling light.
However one of the most frequently raised issues is "how to I change my sound"? The amp is configurable in the X-Air Edit software, but once set there's no way to easily adjust it during performance.
X Air-Guitar is an app you can run on your iPhone (or iPad) which turns the X-Air into a 4 channel amp, with switching from Blueooth pedals.
In the X-Air Edit software, set one of the FX units to "Dual Guitar Simulator". Press the Insert button so that the amp sim is inserted into the signal chain of a single channel, rather than an fx bus, and select the channel the guitar is plugged into (Use 1 or 2 on an XR-18 as that has high impedance), then remember to click the little FX icon to the left which enables the insert. As the fx unit provides two Amp sims, it can be inserted on a second channel for another guitarist if needed. While in X-Air Edit, note the IP address of the mixer (either in the window top bar, or in the setup panel).
On launch the app should display the setup screen. Enter the IP address of your mixer, the number of the fx unit you want to control, and select a or b to control the first or second amp sim.
Then use the tab bar at the bottom to select between the 4 channels. For each channel, drag the sliders to create the sound you want, then press save. Saved sounds will be remembered next time the app is launched. If you feel your edits have gone in the wrong direction you can "revert" to load the last saved sound for that channel.
The app will work with any Bluetooth pedals that generate cursor keys (this mode 2 on Arturns, and Keyboard A on M-Vaves). We recommend the M-Vave Chocolate, or Cube Turner as cheap and reliable options.
Pressing one of the (up to) four pedals will select a different channel. Note this doesn't work in setup mode - select your first channel manually.