I experimented a bit.
Assign Key/Seq source to VCA, and set amount to -100.
Since I did not feel this was enough effect on higher keys I inserted VCA again in 2 more slots.
- hold assign in empty slot, and turn amount until you find VCA, and set amount there too to -100.
Repeat on a third, and I had higher keys go all silent at some amount.
So adjusted to just -30 or something and I felt bass could be what I wanted compared to higher keys.
So there is basic way to create a key tracking to any amount you wish.
Incredible design on modulation I must say. Kuuuuuuuuuuuudos ARTURIA....