Not manufactured any more.

When Jim Winey brought out Magnepan speakers it made most of these electrostatic and hybrids obsolete.

This is because that, while being more accurate than cones and boxes alone, they are shrill and cause listening fatigue after a short time. They are also prone to blowing out--try an early Phase Linear on them at any volume--and they are expensive and difficult to repair (I did it in my shop--not easy).

For contrast, my 1975 Tympani I-C speakers sound just as good today as they did when new, and I have NEVER had any issues with them at all no matter HOW LOUDLY or softly I play them with very good electronics, which are required for accurate speakers.

They were fun when new, and certainly helped lead the way to Maggies, but they did not make the long haul.  If I am not mistaken, Magnepan is still in business and innovating every year.  Try them IN YOUR ROOM and see for yourself.

Cheers!

OR, Bob Fulton's J system.  The FMI 100's were not bad for boxes; this system came with the slightly smaller FMI 80's, which were pretty good as well.  I would guess they hold up today as well, although there have been improvements in boxes since then.  If you like box speakers, that is...

Mark Levinson HQD since people seem to like his stuff, which is not very good.

We made some of the stands for these AND the Hartley 24" woofer cabs.  HUGE!

@jdoris 

When Jim Winey left 3-M and invented Magnepans, boxes became obsolete.  I am sure there are some very fine ones out there, and Maggies are not for every room or every hardware set-up, but pair them with some good HW (Audio Research, for example) and have them set up properly IN YOUR ROOM.

If then you still prefer boxes, go for it.

Cheers!

@jdoris 

Exactly!  As a former dealer, I totally understand your POV, and given that at any one time there are about 300 speaker manufacturers out there, Maggies are not for everyone.  The type of music one listens to, the room (THE MOST IMPORTANT PART OF ANY SYSTEM), and personal taste rule.

My experiences with all types of speakers over the years says that some pretty inventive design points are out there as we can see from this thread.  The range of drivers and enclosures is breathtaking and fun.  

In the end, every designer was looking to give the best sound for their product (other than those who were just playing around for money), and some serious stuff has been invented.

My personal opinion is just that, personal, and I sold many of these boxes to happy customers over the years.  While I can appreciate your love for a specific SPL, I kind of bet you (for fun) that I can set up a Maggie system that will blow you out of your shorts given the right room, etc.

BUT, thank goodness for those 300+ makers out there since there are as many people who love what they do as who prefer what I like.  Keep the hobby alive!

Cheers!