VLC player doesn't play the subwoofer, even when set to directX sound with 5.1 surround and my (correct) speakerset selected. The file is .ac3, directly converted from youtube, which DOES play the subwoofer.
Test the converted file with another system, it likely no longer has 5.1 sound so does not have a separate subwoofer stream to send to the sound card. Set the audio to 2.1 and see if that works.
Test the converted file with another system, it likely no longer has 5.1 sound so does not have a separate subwoofer stream to send to the sound card. Set the audio to 2.1 and see if that works.