As the Large vs Small goes, and I'll certainly check w/ someone else that has the 4311; but when I go into my Settings>Base Mgt>LFE&Main. So, when my speakers are set to Large & I select LFE&Main: it says "Play low range and LFE signals of all channels." So, I guess I thought it was implied that the Sub & Mains would both reproduce the shared frequencies (in my mind I picture a Venn Diagram; & the overlapping area would be the common frequency that they'd both reproduce)....
I'm glad fuzz covered that bit; I failed to address the "double bass" function, partially due to laziness, but also because I didn't want to spend time talking about this choice of inaccurate function.
And as far as multiple drivers pushing the same frequencies; I guess I just likened it to someone having multiple subs (obviously this being apples & oranges after a certain point). I only have one sub; but it seems like I run across MANY folks that sing the praises of running multiple subs in their HT. So, I figured (referring back to the frequency Venn Diagram) it would result in a 'fuller' sound in that overlapping frequency range. . . it sounds like you're saying I'm wrong here . . . which is fine; I just thought it made sense.
Yes, and when they have multiple subs, they will reduce the levels for each of them. They will have greater headroom for sure, in the case they were maxing out prematurely at high volumes. They get more even EQ response. So I can see why you're asking what you are: But here's the thing, YOU ALREADY HAVE the "Venn diagram" as soon as you apply a xover. Did you look up "crossover slopes" like I asked? Once you set a speaker to small, there is a large range of audio that the subwoofer and speaker are sharing. Yes, true.
When you said 44hz or whatever it was, I will assume that is the -3db point. Did you know that it takes a doubling of power for a 3db difference? Therefore your speaker is *naturally* so much quieter down at 44hz, that it's like the receiver decided to only provide it half the power right there. (Hence, my attempted explanation as to why some people advise selecting a xover point considerably higher than the -3db point; because response usually falls even faster below that point, sometimes like "off a cliff".)
So let's play with your idea of Venn diagrams. Let's say the range of 20Hz-20kHz represented a line 6" across, and that you have two speakers, ahem two circles, that are responsible for this length. Let's say you want a perfectly balanced freq vs amplitude. So you throw a test tone, uh test color, of Funny Yellow Food Coloring #425581 with a specific color temperature of 2,462 Kelvin. At every point along this 6" line, an accurate system would have it at 2,462 Kelvin. THEREFORE, if you have two perfectly yellow circles overlapping, at the area of overlap, it's TOO DARK. One or both must go lighter for the system to be accurate. Now let's say you could halve the pigmentation for each, so that the sum is perfect, linearally, but it works a bit differently with speakers:
The greater the overlapping area with the two circles, the gentler the xover slope. The less of an overlap there is, the steeper the slope. In both cases however, the right edge of the overlapping area will have most of its pigmentation from the right circle. Way on the left side of the overlap, the right circle is almost giving nothing at all. Make sense? This is how a xover works, in concept. If neither circle had any "give" in the middle, it is now too dark compared to what would be accurate.
So say you capitulate that you might want a higher xover, but dammit, you just want as much overlap as humanly possible; you're just not gonna give this desire up. Not only do you have to worry about what fuzz was saying, if you get high enough in freq, your subwoofer becomes localizable. Wouldn't it be weird to hear a voice coming from a corner subwoofer every time someone spoke? Sure, this won't happen until at least above 80hz, but this is the thing I'm sort of repeating: your sub is already playing frequencies above 80! There isn't any need to go for more overlap than what you probably already have.
