Launched at the same time as the futuristic APM-8, the SS-G9 was unfortunately but previsibly eclipsed by the former - something today's marketing geniuses wouldn't risk, would they ?
The G9 is a bigger SS-G7 : same Carbocon, AlNiCo V circuits and enclosure engineering, only much bigger : the G9 in fact fits into the enclosure of an APM-8... at 87kg apiece.
The multi-wiring terminals weren't a novelty at Sony : all high-end Sony loudspeaker sported that feature right from the very beginning of the ES series in 1965 and the original SS-3300.
There also is a regular all-together wiring possibility besides the separate inputs shown below.
The filter is partly potted in SBMC, uses ultra-select parts and wiring and is sized like the G9 enclosure : big. Actual impedance makes an easy load with the lowest point being 6 Ohm at 1,2Khz.
Naturally hand-made, drivers hand-coated, hand-adjusted, hand-sanded and hand-oiled, the production run must have been of about 600 pairs which was a sizeable amount for something that expensive.
However, judging by today's apparent circulation, it'd be easy to think only a handful were made...