What is better 1 bigger sub or 2 small ones

Multiple subs are harder to set up properly

I also disagree with this statement. I agree that it is possibly more difficult. But not necessarily. Once again, it depends. For example, if the room is such that placement of a single sub disallows it to ever be properly set up, that is, no matter where you place it, you have noticeable issues (i.e., frequency suck-outs and/or boominess), then a second or multiple subs might be used to eliminate those issues which a single sub cannot. In this case it is then easier with multiple subs to "properly" set up.

According to the book, "Get Better Sound", 2 are required for accurate imaging, and all the old saws about how bass is non-directional are beside the point.

Lloydc,

Theoretically that is true, but for the lowest audible frequencies that a sub would deliver in an already mostly full range system, how much it matters practically is debatable I think.

That using more subs enables smoother bass response throughout the room is a significant advantage nonetheless, if that matters. 4 is even better than 2 and 2 is better than one and the results in most cases should be clearly audible. Audiokinesis is the vendor in these parts who designs some of his speakers in a modular manner that allow for this by design up front.

Its complicated, as all of life is. I have two, which I started with. Felt one would never tell me if two were not better. I am happy.

Can 2 overload some preamps?