Popping noise from my Philips subwoofer

If the audio input is NOT connected to the source when the noise occurs:

There may be signals from the environment which might be picked up by the speaker and therefore produce the noise.

• Connect the audio input to an MP3 player or a computer

If the audio input is ALREADY connected to the source when the noise occurs:

There may be dust or oxidized metal on the connection.

• Disconnect the connections, clean the connecting parts with a soft dry cloth and then reconnect them

There may be dust or oxidized metal on the volume control parts inside the speaker.

• Slowly adjust the volume control knob backward and forward