It is possible to use the CBL-AES1603 on one I/O Port of the AES16, and the CBL-AES1604 (XLR) on the other port. However there are a number of considerations:

1. To utilize a DA-16(X) converter, connect the Lynx CBL-AES1603 cable from the converter to AES16 I/O Port B. For correct operation, the AES16 I/O Port jumpers need to be set to 8-channel mode for Port B, and Port A should remain in the factory default, 4/4-channel mode.
2. In this configuration, Port A should be used for input signals only, since all 16 available outputs are being sent to the DA-16(X) connected to Port B. If the converter connected to Port A is capable of Analog-to-Digital and Digital-to-Analog conversion, only the AD section should be connected to the AES16 via the CBL-AES1604. If the DA section is connected, output channels 1-8 will be mirrored on both ports and the audio quality will be degraded.
3. As you can see, this reduces the number of available channels to 16 out and 8 in.
4. The reverse is also possible: You can use an AD16/AD16-X connected to Port A of an AES16 (in 8-channel mode) and an 8-channel DA converter connected to Port B (4/4 channel mode). Again, this reduces the available channels to 16 in and 8 out.