How do I connect to a mobile device to the DDJ-FLX2? If multiple ways are provided, what are the differences?

There are 2 ways to connect to mobile devices.

 

■ Via Bluetooth

　This unit can be used with any iPhone, iPad, or Android device that supports Bluetooth.
　Connect the power to the unit and use the app to connect.
　Audio is output from the iPhone, iPad, or Android device.
　Audio is not output from the speaker terminals or headphone jack of the unit.

 

■ Via USB

　Any iPhone or iPad and some Android devices that have a USB Type-C port can be used with the unit.
　Simply connect them with a USB Type-C cable.
　Audio is output from the speaker and headphone terminals of the unit.
　No audio is output from the mobile device.

Note: It's not possible to use a USB cable to connect the unit to an iPhone or iPad with a Lightning port, or some Android devices.
Connect these types of devices via Bluetooth instead.

Note:
When connecting an iPhone or iPad with a USB Type-C port, you can easily enjoy DJing with low latency without external speakers by the following methods.
Enable [Output audio from the iPhone speaker only] or [Output audio from the iPad speaker only] in [Settings] > [Audio] in rekordbox for iOS.
If enabled, audio output and some operations will be restricted as follows.
・Listening with headphones connected to the unit is not possible.
・The audio output can't be adjusted by turning the [MASTER LEVEL] knob on the unit.
・No master audio is output from the unit.
・Audio from the microphone connected to the unit won't be output from the mobile device.