"Keystone Series" with this designation:

KS2, KS3, KS22, KS100, etc.

Definition of keystone from Webster's:
"1 : the wedge-shaped piece at the crown of an arch that locks the other pieces in place
2 : something on which associated things depend for support"

The picture of the rear of this new speaker reminded me of a keystone, and the concept of this speaker fitting into a wall to provide "support" for an audio system seems to fit as well.