While there are two mini-jacks together on the back of the Broadcast Host, only one of them is an Output. The jack that is marked “Send 2” is a second input to the Broadcast Host. This is where you can connect another device, such as a CD player, to add audio to the conversation. The jack on the right is a stereo Output, with the Send audio on the left channel and the Caller audio on the right channel of the same stereo cable.