Easily connect your PA system to any PBX telephone system through the telephone handset cord. Innkeeper PBX can prevent feedback and allow full duplex conversations. The Digital Signal Processor (DSP) continuously monitors both transmit and receive audio signals to deliver excellent separation. This proprietary, dual-convergence echo canceller algorithm can achieve excellent separation without any setup, and without sending a noise burst down the line. Innkeeper PBX provides connections for a microphone, headphones, mixer, sound card, and telephone handset. The stereo output jack on the back of the unit provides your voice on one channel and only the caller’s voice on the other channel. The balanced XLR output jack contains only the caller’s voice. The Handset and Broadcast buttons select between talking on the handset, or sending and receiving through the audio connections.