most advanced speaker in a rectangular wooden box?

+1 @helomech.  Yes, so mainly Brits: ATC, Harbeth, Spendor, Tannoy, and let's not forget PMC and Proac.  Top of all those lines are some great speakers.  Apparently more than one way to skin a rabbit.

Proac

Maybe these,

http://www.tektondesign.com/ulfberht-be.html

Harbeth speakers are musical, with a very good sound field, and look good in a traditional setting. I am very, very happy with my Compact 7s. And I have listened to a lot, starting with McIntosh speakers about 50 years ago. You cannot go wrong with products from this manufacturer.

The key word is "Advanced"  
Not a lot of truly new technologies...  
Look at passive crossovers... Off the top of my head, I can think of maybe  8 types of slope technologies besides the amount of slope applied,  yet today, there are mainly 3 types with varied slopes of technologies used. There are more used of course between Parallel and series circuits, but still most use 1 of 3.  All 3 have been around for alooooong time. 
I have seen new driver technologies, with materials used and how those materials affect the overall sound. 
Back in the late 70s, we were playing with active speakers, there are advancements for sure.  Harbeth and Spendor are well very well done. The Avid speakers mentioned are sprinkled full of truly advanced technologies, but of course, they are not in a rectangular wooden box. 
In the end, what makes a great speaker are not Yet Advanced Technology.  Don't get me wrong, even old school technology has improved... what, how?  Driver tolerances, capacitor tolerances, resistors be 1 to 5 percent.  All of these things have improved what we hear regardless if it is an old school paper cone or a titanium, beryllium or carbon cone. Tons of improvements even in the "Not so Advanced" Camp.