Glensound Signature SD1

Silence Detector

The Glensound Signature SD1 is a silence detector used to switch audio to a backup source when the primary audio source falls below accepted silence thresholds in level or time.

SKU: 108614



Glensound Signature SD1

The Glensound SD1 comes with primary and backup inputs, used for stereo or 2x mono signals.

The Signature SD1 is a silence detector used to switch audio to a backup source when the primary audio source falls below accepted silence thresholds in level or time. These are often used on a broadcast path to prevent dead air should a technical problem occur with the audio.

The audio connections are stereo, on analogue XLRs. There is an input pair for the primary source and an input pair for the backup source. The SD1 can also be configured as a twin single-channel silence detector. The backup source is usually coming from an audio player which can be remotely started by the SD1 via a GPO should silence be detected.

Each channel can have the configuration parameters set independently. The threshold at which the unit detects a low level is configurable, as is the amount of time that the audio needs to be under this level before an alarm condition is triggered and the audio is switched to the backup input.

A comprehensive set of GPIOs allows for triggering external devices when the second input has been triggered.

Intelligent modes can be set to allow for switching back to the primary audio source once a sustained audio level has returned.

With a stereo audio source, if one channel should fail, the SD1 can be set to switch this single input to both outputs, making a problem unnoticeable to any listeners, whilst at the same time still providing alarm outputs so the engineers can be alerted.

An internal switch mode power supply is provided along with an external ±12V DC input for the main or backup power supply of the Signature PS1 Power Station.

Silence Detection Parameters
For the detection of drops in audio level, a threshold can be specified between -60dB to -10dB. If the audio level is under this level for a set amount of time, then the SD1 will switch to the backup source, preventing any dead air situations. The fail delay time is configurable between 5 seconds and 5 minutes. When the audio switches to the backup source, a GPO is triggered to start a backup audio source which is connected to the backup input. A GPO is created so that the engineering department is alerted. All switching between the primary and backup sources is silent.

When primary audio has returned, the SD1 can be used in manual or automatic mode. In automatic, the SD1 switches back to the main input after a recovery delay, that’s configurable between 5-60 seconds. In manual mode, the main input must be selected via the front panel or via a GPI switch.

Stereo Or Dual Mono
The SD1 can monitor a single stereo source and switch the output to a backup source if a silence condition is triggered. It can also act as a dual mono silence detector, taking in 2 mono sources and switching them, independently, to their own backup audio in the event of a silence condition trigger.

In stereo mode, if one channel becomes silent, the SD1 can perform two configurable functions. It can either feed the one good primary input to both primary outputs or trigger the silence detect to switch to the backup input.

Audio Connections
The audio connections are stereo on analogue XLRs. There is an input pair for the primary source and an input pair for the backup source. The backup source can be selected to be at 0dB or +10dB. The +10dB option allows for the connection of a domestic level audio source, such as a CD or a memory card player, that may be used as the backup.

Smart Fail & Smart Recovery
Smart recovery mode prevents pops and clicks from triggering the recovery switch back to the main input and waits for a configurable period of time. This allows full recovery of the audio before switching back to the primary source.

A 25way d type connector contains all of the available GPIO, for output remote starts and alarms, and for input switching. There are GPOs to indicate if the primary or backup input is active, which can be used as an alarm that a backup switch has been activated.

Configuration Screen
A front panel screen shows visual feedback of the status of each input and the value of the fail or recovery timer. This screen also accesses the menu for configuration.

Bypass Relays
In event of power failure, the primary audio input is switched directly to the audio output via relays, so that there is no loss of audio.

Power Supply
The SD1 has an internal switch mode 100-240V AC power supply using an IEC connection. There is also an external ±12V DC input to connect to the Signature PS1 Power Station as the primary or backup power supply.

Signature Series Standard Features

19″ Rack Mount Ears
A Signature unit can rack mount in a 1U 19” rack, regardless of the size of the unit.  Rack ears are included as standard with every unit.

Front Or Rear Mounting
A Signature unit can be rack mounted via the front panel or if it is more convenient, via the rear panel by simply swapping the rack ears over.

Side Wings For Flat Surface Mounting
A Signature unit has side wings with mounting holes at the top and bottom, allowing flush fixing from above OR underneath.

Internal Switch Mode AC Power Supply
A Signature unit has an internal switch mode AC power supply, allowing worldwide power connections from 100-240V via an IEC socket.

12V DC Power Connection
All Signature units (except PS1) have a 4-pin XLR ±12V DC  socket for connection to the PS1 Power Station.  This can act as the primary or backup power source.

Quick Find Manual
A Signature unit has a QR code attached.  This can be scanned to simply and quickly locate the manual and technical information.


  • Neutral colour scheme to complement Equipment Scheme
  • Rack screws included
  • Modern design

It may be delivered with a black finish.