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Clocking & Sync

The console and stageboxes must all share a common digital clock sync reference.

Live's internal clock should generally be used to clock a system of console(s) and stageboxes. No external clock is needed unless a specific application requires it. Any external clock must match the sample rate at which the Live console is running (or PAL 25/NTSC 29.97 video).

Note: If an external clock is used, we recommend that only the console be connected to the clock source and the stageboxes clocked from the console's MADI or Blacklight streams. If the external clock source is lost, the console will revert to the next available clock source (e.g. its internal clock) and the rest of the system will remain in sync. We therefore do not recommend connecting external clocks to each of the individual stageboxes as each unit will free run independently without a common sync source.

System Examples

The links below provide connection examples for common configurations. The rest of this page describes the clocking functionality available in further detail.

Clock Source

The console may be clocked internally, or externally via video, AES, wordclock, MADI, or Blacklight II (in a dual SSL console system). This is chosen in Menu > Setup > Options > SYSTEM tab.

Select the required clock source (if MADI or Blacklight II, press the button again and select which MADI/Blacklight port to use) then press & hold the APPLY button. Ensure that the Requested and Actual sources match.

If the clock source is lost, the console will try other clock sources in this sequence: BLII, MADI, video, AES, wordclock, internal, until it finds a valid clock. The original but lost source will need to be manually reselected and applied once it has been reconnected - it will not switch clocks back and forth automatically in case of an intermittent clock source.

The status bar at the top of the main screen will show a clock source change to warn the operator.

Clocking from a Blacklight II Concentrator

Two consoles may be connected to a Blacklight II Concentrator for sharing a set of stageboxes. The 'Master' console (designated as such by connecting to the Blacklight Concentrator's A ports) will distribute its clock to the Blacklight system and any stageboxes and consoles connected to it. The 'Slave' console (designated by connecting to the Blacklight Concentrator's B ports) should therefore set its clock source to the corresponding BLII port on the rear of the console.

The Master console should distribute either its internal clock over Blacklight, or one of the external clock source options listed above, with the exception of any Blacklight port of which it is the Master. Selecting the BLII clock source button will reveal a subset of buttons. The Slave console should use the Blacklight II option. However, the Master console may use one of the MADI options if an external MADI source is connected to the corresponding MADI input on the Blacklight Concentrator. This could be a MADI feed from a third party device providing clock, or wordlock via a stagebox set to its external wordclock input.

Clocking from the local Dante Expander port

Dante uses its own Clock Election process to determine the most appropriate Clock Master for the Dante network and a Clock Master will be chosen automatically. For more information on the Dante Clock Election process please see the Audinate website: dev.audinate.com/GA/dante-controller/userguide/webhelp/#clock_synchronization.htm.

To choose a Clock Master manually, set this device to be the Preferred Master. To do this, open Dante Controller and click on the Clock Status tab. Check the Preferred Master checkbox for your chosen Clock Master.

If multiple devices on the network are Preferred Masters, the Dante Clock Election process will automatically choose a Clock Master from the multiple Preferred Masters.

If the Clock Master's status changes, or a more suitable Clock Master comes online, the Dante network will go through the Clock Election steps again to determine the most suitable Clock Master for the network.

If you are not using Dante network redundancy, please use the primary connection (rather than the secondary) to ensure accurate synchronisation.

SSL Recommends: SSL recommends that the console is set to clock from the Dante network (slave mode) to benefit from the Dante clock election process.
Setting up the Console as a Slave of the Dante Network

In this configuration, a Dante device other than the console is the Clock Master. The console and all other devices on the network will clock to this master.

In Dante Controller, go to the Clock Status tab. Check the Preferred Master checkbox for the Clock Master device(s) if you wish to set one. Dante has its own clock election process, so it is not necessary to set a Preferred Master. For this example ensure that Preferred Master and Sync to External are unchecked for all other devices on the network (including the console's Dante Expander).

On the console, go to MENU > Setup > Options > SYSTEM tab. In the SYSTEM CLOCK section, select Dante Expander and press and hold Apply. Check that both the Requested and Actual fields above list Dante Expander.

The chosen Preferred Master (if set) is now the Clock Master of the network, including the console. The console is now clocking from its Dante Expander module. The Dante Expander module is clocking from the Preferred Master on the Dante network. All other devices on the network are clocking from the Preferred Master on the Dante network.

Notes:
If selecting Dante as a clock source on the console, the console clock selection scheme will not drop back to another clock source if the Dante network clock is lost. The Dante Expander module incorporates an internal clock which will become the Clock Master of the Dante network in this instance until another device on the network is identified as the most suitable Clock Master from the Clock Election process.
Important:
It is not recommended to clock the console from Dante if the Dante SRC In is engaged.
Consoles clocked from stageboxes via MADI or Wordclock are not recommended to be used as Dante network Clock Master sources.

Setting Up the Console as Clock Master of the Network

In this configuration the console is the Clock Master of the network and all other devices on the network will clock to the console.

To set this up, on the console, go to MENU > Setup > Options > SYSTEM tab. In the SYSTEM CLOCK section select Int for the console's internal clock and press and hold Apply. Check that both the Requested and Actual fields above list Int.

In Dante Controller go to the Clock Status tab. Check the Preferred Master and Enable Sync To External checkboxes for the console's Dante Expander.

Ensure that Preferred Master and Sync to External are unchecked for all other devices on the network.

The console's internal clock is now the Clock Master of the Dante network. The console's Dante Expander module is clocking from the console's internal clock, and all other devices on the network are clocking from the Dante Expander.

Important:
Due to Dante's clock election process, any device subsequently connecting to the network which is also set to Preferred Master and has a lower MAC address than the console will be elevated to network Clock Master. In this scenario the console and Dante network clocks will no longer be in sync and could cause loss of audio. SSL therefore recommends that this configuration is not used as it does not offer network clock redundancy.
Clocking over a BLII or X-Light Bridge

Dante uses its own Clock Election process to determine the most appropriate Clock Master for the Dante network and a Clock Master will be chosen automatically. For more information on the Dante Clock Election process please see the Audinate website: dev.audinate.com/GA/dante-controller/userguide/webhelp/#clock_synchronization.htm.

To choose a Clock Master manually, set this device to be the Preferred Master. To do this, open Dante Controller and click on the Clock Status tab. Check the Preferred Master checkbox for your chosen Clock Master.

If multiple devices on the network are Preferred Masters, the Dante Clock Election process will automatically choose a Clock Master from the multiple Preferred Masters.

If the Clock Master's status changes, or a more suitable Clock Master comes online, the Dante network will go through the Clock Election steps again to determine the most suitable Clock Master for the network.

If you are not using Dante network redundancy, please use the primary connection (rather than the secondary) to ensure accurate synchronisation.

SSL Recommends: SSL recommends that the console is set to clock from the Dante network (slave mode) to benefit from the Dante clock election process.

Setting up the Console as a Slave of the Dante Network

For the most reliable clocking scheme, SSL recommends that the console is set to be a slave of the Dante network when using a BLII or X-Light Bridge.

In this configuration, a Dante device other than the console is the Clock Master. The BLII/X-Light Bridge is set to clock from the Dante Network, and the console clocks from the Bridge.

If you have a preferred Clock Master device on the Dante network, check its Preferred Master checkbox in Dante Controller's Clock Status tab.

On the console, go to MENU > Setup > Options > SYSTEM tab. In the SYSTEM CLOCK section, select BLII 1 and press & hold Apply. Check that both the Requested and Actual fields above list BLII 1.

On an L500 Plus with two pairs of BLII ports fitted, select either BLII 1 or BLII 2 depending on which BLII port has been used to connect to the BLII Bridge. To select BLII 2, tap BLII 1 twice and a drop down menu will appear. Tap 2, then tap Blacklight II. Press & hold Apply then check that both the Requested and Actual fields above list BLII 2.

If configured correctly the following LEDs will be seen on the BLII/X-Light Bridge:

BLII Bridge LED X-Light Bridge LED LED Meaning If configured correctly will light
BL S XL S Receiving sync (clock) from console via BLII/X-Light connection Off
SRC SRC Not currently used Off
NET S NET S Receiving sync (clock) from network Solid Green
GM N/A Device elected as network Grand Master Off

(The GM LED is located to the right of the Dante ports on the front of the BLII Bridge.)

If no Sync LEDs lit

If the system has been configured correctly as above but both the BL S/XL S and NET S sync LEDs are off then the BLII/X-Light Bridge has likely been elected clock master of the network (i.e. no other Preferred Masters were found on the network). This is a valid clocking scheme. The BLII/X-Light Bridge will clock the console and the network from its internal clock. The BLII Bridge's GM LED will light in this scenario. The Clock Status page in Dante Controller will indicate the currently elected clock master.

To manually elect the BLII/X-Light Bridge as Clock Master, follow the steps as above, but check the Preferred Master box beside the BLII/X-Light Bridge in Dante Controller.

If the LED states differ from the above please consult the full tables in Working with a Dante Bridge.

Setting up the Console as the Clock Master of the Dante Network

In this configuration, the console's Internal Clock is the Clock Master. The BLII/X-Light Bridge is set to clock from the console, and the Dante Network clocks to the BLII/X-Light Bridge.

On the console, go to MENU > Setup > Options SYSTEM tab. In the SYSTEM CLOCK section select Int for the console's internal clock and press and hold Apply. Check that both the Requested and Actual fields above list Int.

In Dante Controller go to the Clock Status tab. Check the Preferred Master and Enable Sync To External checkboxes for the BLII/X-Light Bridge.

If configured correctly the following LEDs will be seen on the BLII/X-Light Bridge:

BLII Bridge LED X-Light Bridge LED LED Meaning If configured correctly will light
BL S XL S Receiving sync (clock) from console via BLII/X-Light connection Solid Green
SRC SRC Not currently used Off
NET S NET S Receiving sync (clock) from network Off
GM N/A Device elected as network Grand Master Solid Green

(The GM LED is located to the right of the Dante ports on the front of the BLII Bridge.)

If colours differ from the above please consult the full tables in Working with a Dante Bridge.

Important:
Due to Dante's clock election process, any device subsequently connecting to the network which is also set to Preferred Master and has a lower MAC address than the console will be elevated to network Clock Master. In this scenario the console and Dante network clocks will no longer be in sync and could cause loss of audio. SSL therefore recommends that this configuration is not used as it does not offer network clock redundancy.

Setting the Sample Rate

The Live system can run at 96 kHz (recommended) or 48 kHz sample rates. Use the 96 kHz and 48 kHz buttons in the System page (MENU > Setup > SYSTEM) to change the console's sample rate. The stageboxes must also be changed to match the console's sample rate; see below.

Aside from the FX Loop and optional Dante module interfaces, decreasing the sample rate to 48 kHz does not increase the total input/output count; each MADI port carries 64 channels at 48 kHz but odd-even MADI port pairs are always redundant (even-numbered ports on twin card Blacklight Concentrator are disabled).

Important: Changing the console's sample rate will interrupt audio and cause routes to be dropped as stagebox configurations will need to be changed. Muting all outputs to switch sample rate and for a further 30 seconds is recommended.

Important: The console must be rebooted following a change in Sample Rate.

MADI Stageboxes

By default stageboxes are set to clock from the incoming MADI stream. This is the recommended setting. Other stagebox clock sync options are internal or external wordclock.

The clock source and sample rate can be set from the physical setup controls on the rear of each stagebox. The current clock source is displayed to the right of the SETUP area: if neither clock LED is lit, the stagebox is running on its own internal clock.

Note: The wordclock output transmits the clock signal currently in use by the stagebox (i.e. it is not a loop thru), depending on the stagebox's clock source setting).

To change the clock source, press & hold REMOTE and CLOCK simultaneously until the padlock flashes green. Press CLOCK until MADI is lit. The colour shows the following:

To change the sample rate of the stagebox, unlock the controls as described above then use the RATE button to cycle through the available options.

Note: Only 48 x1 and 48 x2 (96 kHz) clock rates are currently supported.

Stageboxes running at 48 kHz sample rate can be daisy-chained on a single MADI stream, allowing all 64 channels of the MADI protocol to be utilised. With the controls unlocked, use the ID button to toggle between channels 1-32 and 33-64.

Refer to the System Examples section below for further information.

Note: If running at 96 kHz sample rate (48 x2), the ID field must be set to 1-32.

The controls will return to their locked state after a few seconds.

AES/EBU

All AES/EBU ports have sample rate converters (SRC's) available. These are enabled by default via the console's I/O menu.

Select the local I/O or D32.32 stagebox in the I/O page and select the specific AES/EBU input or output you wish to sample rate convert from the lower section of the screen.

For inputs, you will be presented with a SRC In button for the selected port. The console supports the input rates listed in the input Fs column in the table below and will convert the incoming audio to 96 kHz (or 48 kHz).

The table below shows sample rates available for AES/EBU outputs. There are additional controls for AES outputs, as shown above.

Note: The multiplier controls (x1, x2 and x4) are relative to a base sample rate of 44.1 or 48k, not the operating rate of the console (48 or 96k).

Engaging SRC In and setting the output clock to In will clock the AES output from the corresponding AES input, at 1, 2, or 4 times the base rate (44.1 or 48k).

Setting the output clock to Int will use the console as the clock source. This can also be set to x1, x2, or x4 of this base sample rate (48k).

Tip: Setting the output SRC to In will set this AES port's output to clock from the corresponding input rather than the console clock. This is useful if the external device has issues clocking to an external clock. This setting will allow the external device to use its internal clock, with the Live console's AES SRC locked to the external device, allowing the device to clock itself thus avoiding clocking errors.
For example, if using a 96 kHz reverb, set it to internal clock and set the console's SRC settings to SRC In for both input and output AES/EBU ports. For the output port, select In and x2 (for 96k).

Useful Links

Local/MADI I/O Configuration
Setting Up Dante
Installation Guide
Index and Glossary
NEXT: Local & MADI I/O Config