Here's the lowdown:

MADI is not like word clock.

MADI uses 75 ohm coax, but is point-to-point only and does not allow daisy-chaining. Thus, it does not require any external termination — this is done internally on both transmitter and receiver ends. T-connectors should never be used.

The proper connections would be:

RME MADI out –> 75 ohm BNC cable –> H9000 MADI in.

H9000 MADI out –> 75 ohm BNC cable –> RME MADI in.