I made a few updates to the review based on the feedback I saw at the Emotiva forum.
Thank you, Gene, for quickly revising the review. I would make some clarifications to my post at Emotiva, too, except ole' Dan locked the thread! I will make them here and address your post as well, if I may.
I informed Emotiva about my findings and they are working on a firmware update to disable the option of combining LFE signal back into the main channels with the "enhanced bass" feature turned on.
Wow. I am sort of surprised that they are planning to change the Enhanced Bass mode, since it operated exactly as the UMC-200 manual described: "
allows you to route the LFE signal to ALL speakers that are set to large," just as your tests confirmed. Nevertheless, I do think it is better to change it to act like "LFE+Main" as that is much safer for the main speakers, and fully achieves the desired result: allow the sub to supplement full range mains.
I don't think anyone can say for certain what will ALWAYS be in the LFE channel. I put in a call to Dolby to see if I could get some clarity on this issue.
I was trying to make the point that the notch you found will not be an issue under normal circumstances. By saying it will
never be an issue I was overstating the case for dramatic effect. Technically, yes, you are correct, there are undoubtedly some unfortunate mixes out there where the LFE was derived directly from the main channels. I say unfortunate because when such signals encounter the consumer's bass management, the compounded phase shifts will degrade the subwoofer signal (like with notches!). Anyway, with the impending redesign of Enhanced Bass mode, the issue will be totally moot.
I've personally found that LFE channel must also contain audio from the other channels since when I tried to run the Status 8T as large and a dedicated sub channel, they 8Ts weren't getting much bass at ALL for multi-channel sources. Disabling my bass management so that LFE routes to the main channels made a huge difference, especially on music Blu-rays.
I'm a little confused by the highlighted part, but I think I get the jist.
Yes, since the loudest bass in a 5.1 program is typically in the LFE channel, you will hear more bass when the LFE signal is used, whether it is heard from the mains or the sub. If your main speakers handle LFE better than the subwoofer (assuming one is available), then by all means, use the mains. I think this is an
exceedingly rare condition for most home theaters, particularly if the sub (or subs) are well situated and tuned. In that case, the best overall results will happen with standard bass management.