It's only possibly with HDSPe AES and HDSPe MADI, the HDSPe MADI FX has a driver of its own.
Then you will have a TotalMix FX instance/window per card.
Routing of audio between the two cards needs to be performed by the application.
Clock synchronization can be performed by using
— WC (Word Clock) or
— internal X401 Sync Out, X400 Sync In connectors, see manuals ch 6.2
When using multiple cards, then you need to check manually in the driver settings, that all cards use the same ASIO buffer size.
How many AES stereo ports do you need?
If you require only 1x AES I/O and MADI, then you have these options
a) get HDSPe MADI FX card (PCIe), then you have the advantage to get a card with
— resource optimizing driver
— full implementation of FX chip
b) get UFX+ (USB3/TB) which also has 1x AES and MADI I/O and besides that many useful features
and then you can route audio in one TM FX instance between all inputs / outputs.
c) get MADIface XT (USB3/ePCIe) which has 1x AES and 3x MADI I/O
Alternatively, you can select any RME recording interface with MADI (e.g., UFX+, MADIface XT, HDSPe MADI, HDSPe MADI FX) and connect
— ADI-642 with 4x AES I/O or
— Octamic XTC which is a preamp but also has 4x AES I/O on board
to get AES ports into your setup and to have full flexibility of routing on one card.
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro