Two medium size woofers Vs One big size woofer

Yes, there are tradeoffs  either way. Can't have it both ways. 

Another factor to consider is a large, 15" or so, woofer properly loaded into a well designed bass front horn can make any combinations or 7" of 5" drivers ashamed of themselves.  The transients, impact, tunefulness, definition and clarity is unequaled by other systems for bass reproduction.

@kingharold --

Another factor to consider is a large, 15" or so, woofer properly loaded into a well designed bass front horn can make any combinations or 7" of 5" drivers ashamed of themselves. The transients, impact, tunefulness, definition and clarity is unequaled by other systems for bass reproduction.

I wholeheartedly agree. Myself I’ve chosen the tapped horn principle - do you know of it, and have you heard any tapped horn subs? A traditional front loaded horn would have suited my requirements very well also, but that’s another discussion. It’s great to see the sound of horn bass/subs acknowledged - you put it just right.

What’s interesting is how the horn acts as a force multiplier in being an acoustic transformer, and thus a horn-loaded 15" like you mention acts and feels quite differently compared to a 15" (or bigger) direct radiator. Even compared to ported subs with 2 x 18" drivers per cab, a horn-loaded 15" to my ears feels more effortless, present and "malleable" somehow, as if the bass flows in more organically and naturally with the rest of the frequency spectrum. Ported 2 x 18" is typically more of a "pounding" experience that potentially stumbles over itself with very demanding bass lines; 15" horn-loaded bass is more a floating/flowing experience that vibrates, or even shakes the whole air volume in the room, making for a very present, enveloping and tactile feel. It’s a shame so few have heard horn (sub) bass..