Mackie DL1608 Reference Manual page 99

iPad Optimization #5 : Mute keyboard clicks, sent and received email alerts, calendar event
warnings, alarms and other extraneous iPad noises (except music apps; those will continue to play).
There are two methods to optimize your iPad here. It's just a matter of preference.
Use Side Switch to: Mute
Now fl ip the side switch on the iPad (next to the volume up/down switch) so that the orange dot is visible.
It indicates that the iPad is indeed muted (except for the music apps).
Use Side Switch to: Lock Rotation
Double-tap the home button on the iPad to reveal the tool bar at the bottom of the iPad.
Now swipe it right to reveal the iPad's audio play bar.
On the far left is a mute/un-mute button. Mute it.
The speaker will be crossed out to indicate that the iPad is indeed muted (except for the music apps).
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