Sonifex RB-SD1 RedBox Silence Detector / Watchdog.

The Sonifex RB-SD1 silence detector is a powerful 1U rack-mount device designed to monitor unattended audio signals with unparalleled precision and reliability. Whether you’re managing a radio broadcast, live event or other audio application, the RB-SD1 provides peace of mind by ensuring your audio plays continuously and without interruption, even in unforeseen circumstances.

Most important features:

Silence Detection and Automatic Switching

Continuously monitors audio signals and detects silence after a preset period.
Automatically switches to an alternate stereo sound when silence is detected, such as a recorded message or an alternate program.

Flexible Input Sources and Detection Options
Two balanced stereo audio inputs with a maximum input level of 28dBu.
User can define each input as main source or resource.
Monitor both sources for faults, with separate remote fault alarms.

Customizable Settings and Operating Modes
Adjustable silence detection level between -60dBu and -15dBu in 3dB steps.
Silence interval adjustable from 2 seconds to 30 seconds, or 2 minutes to 5 seconds.
Can be operated in automatic or manual mode depending on the user’s needs.

Advanced Remote Control Options
Ability to start external equipment and indicate status remotely.
Remote control of all functions including source selection, mode selection and signal recovery.
Programmable options for specific applications, tailored to the user’s needs.

Reliable Operation and Versatility
Passive signal path via main input ensures that the input signal is forwarded to the output in the event of a power failure.
Suitable for various applications, from radio stations to live events and installations at broadcasting locations.

Audio Specification
Maximum Input Level: 28dBuMaximum Output Level: 28dBuFrequency Response:20Hz – 20kHz ±0.1dBGain: 8dB (for unbal input B – optional)

Distortion:As input for balanced input, <0.05% ref 8dBu output for unbalanced inputInput Impedance:>100kΩ balancedOutput Impedance:As input, except when using unbalanced auxiliary input where output impedance <50ΩNoise:<-87dB, unity gain, ref 8dBu output for unbal input

Rear Panel Connections and Controls
Inputs (Main & Auxiliary):4 x XLR 3 pin female (balanced, auxiliary can be unbalanced)Output:2 x XLR 3 pin male (balanced)Remotes:15 way D-type plugAlarm Threshold:-15dBu to -60dBu in 3dB steps via rotary switchSilence Detect Duration:2 – 30 seconds in 2 second intervals & 125 second option via rotary switchDetection Type:Mono or stereo, via DIP switchSilence Switch Defeat:Disable/enable silence switching, via DIP switchRemote Start:Latched or momentary, via DIP switchMains Input:Filtered IEC, switchable 110-120V, or 220-240V, fused, 9W maxFuse Rating:Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm(115VAC)

Front Panel Controls and Indicators
Controls (with indicators):Source select, mode select and restoreIndicator:Program and alarm indicators for left and right source for both main and auxiliary channels

Equipment Type
RB-SD1:Silence detection unit

Physical Specification
Dimensions (Raw):48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
19” (W) x 4.3” (D) x 1.7” (H) (1U)
Dimensions (Boxed):58.5cm (W) x 22.5cm (D) x 7cm (H)
23” (W) x 8.9” (D) x 2.8” (H)
Weight:Nett: 1.4kg  Gross: 2.0kg
Nett: 3.1lbs Gross: 4.4lbs