The CS7 was created in the mid 90s transition between Vifa making the drivers we co-developed with them vs Thiel making everything in-house. That in-house driver manufacturing capability was in force before I left in 1995, but in its infancy. The first driver built in-house was the CS6 woofer, the motor of which was also used in the original CS7. The other CS7 drivers were all developed in conjunction with Vifa.
We had a great run with Vifa, but there is only so far an OEM manufacturer will go in making weird stuff. All of our drivers were out-of-the-box / different from 'normal'. Vifa offered all of our innovations to any of their customers, which made the R&D pay back for them. However, eventually we mutually decided that our needs diverged from their market. This transition occurred over 5+ years and everybody expected what happened. It happened at the CS7.
The CS7 drivers incorporated as much of Jim's ideas as possible, given R&D constraints and especially prototype cycling times. 4-6 weeks was a fast prototype turn-around time which limited iterations to a handful. As Jim and Walter learned how quickly and effectively they could prototype new driver ideas in-house, they set about iterating dozens of advancements. The coax was proven for the 2.e Rapid advancements turned into all new drivers for what became the CS7.2, along with the necessary crossover modifications. Rob says that the great majority of CS7 owners opted to implement 7.2 status with all new drivers and crossover networks.
I heard both models side-by side at Rob's shop several years ago. His room has an all-glass floor to ceiling wall on one side and effectively no wall on the other side with only about 12' between the back and front walls. Far from ideal. In that awkward space with good amplification and cabling, the CS7 was the safer bet. Its presentation was a little smoother and easier, less transiently crisp, and therefore less precise and detailed. The 7.2 had considerably sharper dynamic range and inner detail. Rob had either for sale and someone bought the 7.2s, which was fine with him.
The 7.2 better epitomizes Jim's vision. His last project was creating a next generation coax with a 'better' tweeter and 'better and smaller' midrange for use in the 7.3 and 2.4. That never happened.
