I use Cubase with 3 x MOTU 2408 audio racks. 72 inputs and outputs in total. I wanted a flexible headphone monitor system to allow performers to each have their own mix. After a lot of thought, the Behringer P16 seemed to be the answer. By use of groups, I can send 16 streams to each unit and they can each have an individual mix. The P16-I is the interface that converts the ADAT (or analogue) signals from my audio interfaces into an Ethernet stream that can be passed to the P16 mixers. The front panel has 6 connectors for direct connection to 6 P16 mixers. Or you could connect 6 P16-D expanders allowing up to 48 mixers to be connected! There are also sensitivity controls for the analogue inputs. These are useful if you are connecting to direct analogue outputs from an analogue mixer for example. The unit has LEDS that illuminate to show signal present, ADAT present and how many P16 mixers are connected and working. All in all, a utilitarian product that does a specific range of things very well. If you want to use the P16 system, you need this unit. I'm glad I bought the P16 system and intend to add more mixers to the 4 I bought as funds allow. The P16-I will continue to be at the centre of it all.