i have discovered something very cool that is very simple. in dolby digital 5.1 - the subwoofer output is mono. but there is indeed stereo information that has bass signals to it and this information is easily retrieved. if you set your receiver to 'large' for the front main speakers and then split the main left and right outputs - one to left and one to left subwoofer and the same on the right - you now have stereo bass and it works very well. my levels didn't change and there are tracks on the avia dvd that bounce between specific channels main output and sub output levels so its easy to set up.