PREVIOUS: Setup Introduction

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.

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 > Console.

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.

Blacklight II

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.

Dante

Note that if selecting Dante as a clock source, it will not drop back to another clock source if the Dante network clock is lost. The Dante module incorporates an internal clock which will be used in this instance until the network clock is regained.

If using the console as a Dante network clock master, ensure that both Preferred Master and Enable Sync to External check boxes are ticked in Audinate's Dante Controller software. This ensures that the console's Dante module is synchronised with the console's clock source.

Important: It is not recommended to clock from Dante if the Dante SRC is engaged.
Consoles clocked from stageboxes via MADI or Wordclock are not recommended to be used as Dante network clock master sources.
If you are not using Dante network redundancy, please use the primary connection to ensure accurate synchronisation.

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.

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.

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).

System Examples

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