Hello. Since I am partial to sealed box loudspeakers that can be placed close to the back wall, I grabbed a pair of Canton Quinto 530s when a pair came up cheaply. These were introduced in 1981 and replaced in 1986 by the Canton Karat 300. They appear to be members of the lineage of the AR-3 crossed with the 2ax: a sealed 10" three way with dome midrange and tweeter mounted horizontally to each other. It is the fourth iteration of the basic design dating to the Canton LE600 of 1973, and finishing with the Karat 300 (after which Canton moved to metal dome tweeters).
The entire Canton lineup ALSO shares a lineage with Braun. Their debut lineup (and their successors) look like copies of the Braun 1972 lineup with the Braun L620 the closest to the LE600 three way with rounded edges and metal perforated grill that became the Quinto 530.
I've gathered what info I can on these and will summarize the lineage best I know. Some comes from http://www.hifimuseum.de/braun-kronberg.html.
Braun consulted AR in 1961 about hi-fi speakers. Their first hi-fi model of 1961, the L60, already has the perforated metal grill and elegant lines of ADS boxes. http://www.hifimuseum.de/braun-l60.html
About that time Wolfgang Sekritt began working for Braun and moved up the ladder there. In 1965, after a dispute over pay, he left for Heco. After an ownership change there in 1972, he got together with other veterans of Braun and Heco to form Canton.
Meanwhile, about this same time, ADS began importing Braun speakers to the US to sell under their own name, and then Braun drivers to sell in their own boxes, very similar to Braun's models. Then in the early 1980s (?) ADS began manufacturing their own drivers.
In any event, it appears 1970s-early 1980s ADS and Canton are fruit of the same tree, and the box speakers share a visual aesthetic.'
My question to all of you is who has compared Canton and ADS or Braun speakers from this period. The one thing I've gathered is Cantons may be brighter.