The QR1 and Sonia Amp natively support 4x4 Dante channels across 2x2 Dante Flows.  

Gio supports 2x2 Dante channel across 2x2 Dante Flows.  

The Solaro FR1-D natively supports 64x64 Dante channels across 32x32 Flows.

Before a Dante channel can be transmitted or received it is first packaged into a Dante stream or "Flow." A single Flow can contain up to four audio channels. For a more detailed explanation of Dante Flows please visit the Support section of Audinate.com. 

For the purpose of this article, the important thing to know is that the number of Flows a given Dante-enabled device can support (Xilica or third-party) is synonymous with the number of devices that Dante device can transmit to or receive from.

QR1/Sonia supports 2x2 Flows:  this means that the they can receive from two different Dante devices and transmit unicast to two different Dante devices using a total of 4x4 channels.

Gio supports 2x2 Flows:  this means that the they can receive from two different Dante devices and transmit unicast to two different Dante devices using a total of 2x2 channels.

The Solaro FR1-D supports 32x32 Flows:  this means that the Solaro FR1-D can receive from thirty two different Dante devices (across 64 total channels), and transmit unicast to thirty two different Dante devices using a total of 32x32 channels.  

Note, if the transmitting channels are switched to multicast, then that Dante device can transmit that audio channel to any number of downstream Dante devices as can be supported by your network.