Using Studio monitors as stereo setup

[Kannan]

This really helps is getting significant sound-stage depth when compared to other designs which sound more 2 dimensional without much depth.

this is a very critical part of a speaker design. The ability to produce bass without external reinforcement. The Dynaudio I use now does this with aplomb.
In my earlier passive set-up I had to use a subwoofer to get that extension so that I could move my bookshelves into the room for optimum positioning.
All said, larger drivers do push more air if the enclosure design allows for it to create a more natural bass.

 

[DB1989]

Yes that's exactly what I am alluding to. I used to have 2-3 dynaudio bookshelve models in the past, and while I agree they do put out decent amount of bass when compared to similar sized woofers in other models, the quality of bass produced by a 8" woofer is in a different league - at-least ime. Ultimately the larger woofer wins, both in scale and extension. Another advantage I have noticed is at-least with the mofi, I can pull the speaker out much farther into the room without having the bass collapse as in other smaller book-shelves which use the rear wall for reinforcement. This really helps is getting significant sound-stage depth when compared to other designs which sound more 2 dimensional without much depth.
Cheers,
Sid

Can't disagree - there's no replacement for displacement. The lowest bass frequencies provides the foundation and adds to the soundstage and i suspect the reason why Spendor's do it so well is because they have a very linear roll off all the way down to 20hz and beyond.

Low volume notwithstanding, this is the roll off of the Spendor Classic 2/3 below 100hz - room nodes aside, notice that the speaker is only -6db down at 20hz from that of 80hz.