BLU-HIF Telephone Headset Interface
The BLU-HIF features an RJ-22 jack for connection to the headset jack of a VoIP/digital phone, a balanced input (Tx) for sending near-side audio, and a balanced output (Rx) for receiving far-side audio. While the BLU-HIF provides substantial isolation of the Rx and Tx signals, near-side audio will still be heard on the Rx channel due to the presence of side-tone. As such, BSS Audio recommends always feeding the Rx channel to an AEC input, as opposed to a standard analog input. The AEC algorithm will remove the side-tone. The Tx channel connects to a standard analog output.
The wiring configuration within the headset jack of a VoIP/digital phone often differs, depending on the manufacturer. The BLU-HIF comes with two cables whose 4P4C RJ-22 connectors are compatible with the two most common wiring configurations found in the headset jack of VoIP/digital phones.
The additional 2.5 mm jack facilitates connection of two-way communication devices such as cellular phones to the Soundweb London device. This gives the end user the advantage of having an alternate communication path to the outside world, which is particularly useful as a backup to the main phone system.