That second sub out on my NAD T773 has always begged me to wonder about the merits of having 2 subs versus one. For example, are there benefits to having 2 equal distance from the listening/viewing location (symmetrical), rather than one to one side (assymetrical)? Of course, cost is an issues, but perhaps 2 lower cost subs can surpass 1 expensive sub? Maybe subs are not "additive" and a second does not add much; or maybe 2 would be awesome? And then I can only wonder if there are issues with cancelation, etc., such that positioning is really critical? Anyhow, thought it would be fun to pose the 1 versus 2 question to the audience.