Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
You could probably develop a summing filter like that - and it would be useful on any content that wasn't already summed. But there's where you might find the filter is not all that necessary, because most music is already mixed that way. Get your scope out and watch the L/R channels, and you'll see LF is already summed to be the same on both channels in most music.
As for the rest of the channels for home theater, this approach could surely be extended to the rest of the channels but I'm not sure it is warranted. I guess if the budget allows, it couldn't hurt. But I don't think it is as important as the front mains, especially for music.