For best Wireless Stereo Pairing performance, it is advisable that you place the two speakers within 1.5 to 3 meters range (to get an optimum Bluetooth communication performance - Wi-Fi and other 2,4GHz RF communication may disturb the Bluetooth communication between the speakers). If this happens, you can move the speakers out of this 'RF noisy' environment during the pairing process.
In Wireless Stereo Pairing mode, when your phone gets out of range, it will disconnect the two speakers. You will need to reconnect when back in range.
Wireless Stereo Pairing can be set up manually see our guide here, or you can simply be guided using the Bang & Olufsen app for iOS or Android phones.