Alesis Wedge Reference Manual page 25

Chapter 2 – Connections
have enough Aux sends from your mixer to use the Stereo In hookup described
below.
Stereo In - Stereo Out: This connection is similar to the one described above.
However, by utilizing two sends from the mixer, we add one more cable from a
different aux send to the [RIGHT] input of the Wedge and can now send a stereo
22 Wedge Reference Manual