Sonifex RB-SD1 Silence Detection Unit (1U)

Sonifex RB-SD1 Silence Detection Unit (1U)

The RB-SD1 silent detection unit is a 1U rack-mount gadget that monitors an unsupervised stereo studio feed. If the signal becomes "quiet" after a certain amount of time, the machine will switch to a different stereo audio channel. This signal could be an alternate recorded program, a feed from a CD player or minidisc machine, or a recorded message (like "normal service will be resumed"). There are controls to turn on external devices and show the status remotely. The maximum input level on its two balanced stereo audio inputs is +28dBu. Every input has a remote failure alert and can be configured by the user to be either the primary or secondary source. Both sources are watched for malfunctions. When the primary source falls below a pre-established threshold for a pre-established duration, the device will automatically transition to the backup signal. A 16-position rotary switch on the back panel allows you to alter the silence detect level in 3dB stages, from -60dBu to -15dBu. A 16-position rotary switch on the back panel allows you to set the silent interval to 2 minutes and 5 seconds, or you can increase it in steps of 2 seconds from 2 to 30 seconds. The audio outputs use stereo professional balanced XLR-3 male connectors.

There are two operating modes for the unit: automatic and manual. When it detects silence in any mode, it will immediately switch to the auxiliary source. Depending on the mode selected, it will either automatically or manually return to the main signal when it detects it again. Many functions for remote operations are available with the RB-SD1. Separate relay contact closures for main and auxiliary input failures are provided via remote outputs. All of the front panel switches for source selection, mode selection, and signal restore can also be operated from a distance. You can remotely start and stop another piece of equipment on alarm failure and main signal Restore respectively. Also, the longest silence time (2min 5sec) can be set remotely, which is useful if you are expecting to broadcast a long silence.

When the main input source's left or right channel fails, or if the stereo signal fails as a whole, the machine can be set to sound an alarm. Additionally, you may adjust the remote start output to be either momentary or latching, turn off the auxiliary input's ability to switch on when something alarms and boost the auxiliary input's gain to enable the usage of unbalanced inputs like those from domestic minidisc players. Individual left and right program and alarm conditions for both the main and auxiliary inputs are displayed by the front panel LED indicators. On the front panel, LED indicators display the source, mode, and alert state statuses.

Additionally, the RB-SD1 can be programmed for specific applications which can be defined on the power-up of the unit. Contact Sonifex for further information if you have a particular requirement. (Refer to the handbook on the website for information on current configurations). The RB-SD1 has been designed to have a passive signal path through the main input, so if power to the unit fails, the signal input will still be routed through to the output. This is essential for applications such as installation at transmitter sites, where a power failure to the unit should not prevent the audio input signal from being output to the transmitter.