The Innkeeper 1x from JK Audio is a single line digital hybrid housed in a desktop enclosure. The main function of a hybrid is to extract a caller's voice coming in on a phone line, while keeping it separate from the receiver's outgoing audio. Both these streams can then be controlled in various ways. A digital hybrid provides audio that is clearer and cleaner over the variation in quality found in analog hybrids. The unit functions with both "wet" and "dry" (PBX) phone lines. (Dry line installation is always a custom configuration and requires substantial telephone system knowledge.)
In order to achieve the required separation, an internal Digital Signal Processor (DSP) continuously monitors both the phone line and audio signals The proprietary echo canceller algorithm can achieve excellent separation, typically exceeding 50dB without any additional setup. Signals can be monitored from the front-panel headphone output, with a choice of the caller's voice, the sender's signal, or a mixture of both. This output is also at the rear panel screw terminals, to which an external monitor speaker can easily be added.
An auxiliary telephone jack is provided that can be used to initiate or screen calls, and is disconnected when the "Call" button is depressed and reconnected when the "Drop" button is pressed. The unit features Send and Caller volume controls (hidden behind an access panel) and Caller Ducking drops the Caller output level by 9dB whenever the host speaks allowing the host to remain in control of the show. Additionally, AGC (Automatic Gain Control) keeps the caller volume to a steady, average level.
A "Presence" button engages a digital filter that boost the low frequency content of the caller's signal, to enhance the quality of the transmission. A Test Tone generator sends a 1kHz full-level tone either down the phone line or out the Caller XLR jack and can be useful in setting levels. Applications for the Innkeeper 1x include telephone interviews, talk shows, church PA interface, and conference-room full duplex communication.