You can see a green or blue light at the top of the subwoofer to indicate that it is powered up successfully.
A blue light on the subwoofer means that it is connected successfully to the Soundbar unit and you should get the bass from the subwoofer.
A green light on the subwoofer means that it is not connected to the Soundbar Unit. In the event that the green light is lit, you should establish the connection from the subwoofer unit to the Soundbar. Simply put the Soundbar to standby mode. You should see the red standby light on the Soundbar. Press the STOP button on the remote control and hold it there till you see the word PAIRING on the front local display of the Soundbar unit. While the pairing button is still flashing, press and hold the pairing button at the back of the subwoofer till you see the words PAIR OK on the front local display of the Soundbar unit. The green light on the subwoofer should now change to blue to indicate a successful wireless connection.
After you get a successful wireless audio connection, simply press the BASS button on the remote control to bring up the BASS tweaking option and use the Volume +/- buttons to adjust the bass level to your liking.
Do ensure that the wireless subwoofer is placed no more than 3 m away from the Soundbar unit to ensure optimal wireless performance. Do not bring other wireless devices close to the Soundbar and subwoofer units too.
In case the above does not help, contact Philips Consumer Care for assistance.