Any Large Acoustic Suspension Speakers Being Made?

Sealed box and acoustic suspension are not identical. All acoustic suspension loudspeakers are sealed, but the opposite is not true.

Sealed enclosures are obviously unvented, but the box is big enough to leave plenty of room for the back wave, and the speaker drivers have normal suspensions, rigid frames, and strong magnets to return the drivers to the neutral position.

Acoustic suspension speakers rely on a specific volume of air to power much of the rebound to center after an excursion or incursion of the driver. Thus the acoustic suspension model doesn't need as powerful a magnet, nor as rigid a cone because the air in the sealed box performs much of that function.

As for sealed box speakers, both Magico and YG use sealed enclosures. I'm sure there are more.

One thing about the Dunlavys (and the Duntechs that preceded them)  that is very important to some people is that they use first order crossover slopes, and also that the drivers were staggered to be time-coherent.  Not that many speaker manufacturers do that these days (Vandersteen, Green Mountain, Thiel).  There was nothing really that special in terms of parts in the crossover (although they did use air core inductors, I think), and some A-gon members have made upgrades to the parts in the crossover with some success.  All in all, it was an extremely well-engineered speaker.

rcprince: If you read the Stereophile review of the SC-IVA, you’ll notice the fanatical attention to detail Mr. Dunlavy used in building his speakers. How about a frequency response of +/- 1.5%? He would hand-trim every crossover to match its companion driver. Mr. Dunlavy said this speaker could pass a square wave better than most tube amplifiers! I would love to hear these speakers driven by BEL 1001 Mk V amps (also built with fanatical precision). Try to find a maker that would go to these extremes today!