Once you have generated your channels, you can use the new Sound Forge 9 to play around with your multi-channel audio (and then render as AC3). I don't know of any free program that is able to edit multi-channel audio.
Once you have generated your channels, you can use the new Sound Forge 9 to play around with your multi-channel audio (and then render as AC3). I don't know of any free program that is able to edit multi-channel audio.