I have sound to all speakers apart from the subwoofer. I have no bass whatsoever.

In windows i have to choose the "Bass Redirection" option in AudioHQ to get the subwoofer to work. I'm guessing i need to enable a similar thing in linux.

If it makes any difference, i'm using analog not digital speakers. What must i do to get my subwoofer working? I'm using Fedora Core 3.

Thanks.

You have to play a video or audio that has 6 channels encoded. A DVD movie has 6 channels encoded. A program like mplayer can output up to 6 channels. You have to pass the option channels and the number 6. Also you have to use alsa as the audio output device. The command line will be something:
mplayer -channels 6 -ao alsa:device=surround51 dvd://1

As you can see you have to specify surround51 to handle 6 channels after you specify alsa. The above will play the first title of the DVD, but not all DVD uses the first title for the movie.

ALSA site has wiki documentation on how to copy stereo to many channels. You will get full range (20 Hz - 20000 Hz) on all channels, so make sure you have an active or a passive low-pass filter on the subwoofer channel or else it will sound distracting.