There is no substitute for cubic inch or in this case surface area

My Yamaha NS-5000's have one 12 inch woofer each. You have to look carefully to see them move. It's a 6 ohm driver with a 3.5 pound woofer coil, which I think is key to its incredible bass texture and detail down to 26hz. I rarely hear my subwoofer. 

Midrange and tweeter (4 ohms both) are the identical (to the woofer) carbon fiber coated in Monel (copper nickel alloy). Hence it is virtually impossible to isolate a driver with your ears. 

The rub is this design is in its relative energy inefficiency. The user guide says 200 watts "nominal." I ran them on 250/500 8/4 ohm Ice Modules for a while. Now they are connected to 500/1000 watt Ice Modules which I think is about right. My wife noticed the difference immediately. We have a 13 foot listening distance in an open plan tract house. So no nearfield listening and no flea watt amplification. 

@larryi Wrote:

Truly large horns, with the right drivers deliver scale, impact, and authority at lower volume levels than any other kind of driver.

I agree!

Mike!

Check out a pair of Legacy Focus SEs. They feature 2@ 12 inch woofers. They are incredible. 

The Focus SE’s woofers have a 15 lb motor structure. 

Discounting surround widths, cone depths, voice coil dust cover diameters, and any additional surface available from any ribbing in the cone itself:

6" dia. = 28.27 sq. in.

8"  "     = 50.27  "   "

10"  "    = 78.5   "   "

12"  "    = 113.1  "  "

18"  "    = 254.5  "  "

pi x radius squared for anything else....

I play with truncated cone surface areas.....

Mine work out to be about equal to about a 9" dia. in the diameter of a 6"... ;)

Voice coil suspension and travel is whatever I want to play with, keeping in mind the surround pistonic travel will require.  And not a lot of concern over tariff ruckus for the immediate future....

Mix 'n match to your pleasure, J