The number of N-1/mix minus returns is determined by the configuration.

By default, each source’s N-1 is generated from the programme bus so that the source hears PGM 1 minus themselves. 

The conference system allows one or more conference buses to be configured for particular sources. Each source added to the conference then receives an automatically switched mix-minus feed:

  • When a conference member is on-air, they hear PGM 1 minus themselves.
  • When two or more conference members are off-air, they hear the conference bus minus themselves. This allows the sources to hear each other before they go on-air.

The rest of this topic describes the N-1s and conference system defined in the standard configuration. The operation may vary if the configuration is customized.

Operation

In the standard configuration, each of the following sources supports an N-1 return: Mic 1 to 8, Tel 1 & 2, Codec 1 to 6.

By default, each source receives PGM 1 minus themselves. Sources can be added to the conference system using the Conf keys (on the fader strips) or Conference buttons (on the GUI).

The N-1 return level can be adjusted (from the GUI), or you can talk to a source, via its N-1 return, by pressing the fader strip TB key.

Note that, for each codec source, it is possible to change the return signal (from the GUI). This allows you to send a sum bus or internal tone instead of the N-1 signal.

On the GUI...

1.    Open the 'Source Parameter' dialog box by pressing a fader strip Access key, and choose the Input page.

2.    Use the buttons under 'Conference & N-1' as follows. If an option is greyed out, then the parameter is not available. 

  • Conference - touch this button to add or remove the source from the conference system. The button colors are the same as on the surface (described below).
  • N-1 Return Level - touch and drag anywhere inside the parameter box to adjust the N-1 level: either left/right or up/down. Or use the on-screen + and - buttons.
  • Codec Return Signal - touch this field to select a signal from the dialog box. The following options are supported: N-1, PGM 1 to 3, REC, AUX 1 to 4 and Tone. The on-screen meter can be used to confirm that signal is present.

On the surface...

The Conf key assigns a source onto the conference bus. What the source receives depends on the status of the source fader and that of the other conference members. 

The Conf key color indicates the current state. The colors used can be modified by the ON-AIR Designer. The following colors are used in the standard configuration:

  • Dim white = conference off. Source receives PGM 1 minus themselves.
  • Full green (Conf prepare) = conference on and fader open. Source receives PGM 1 minus themselves.
  • Dim yellow (Conf active) = conference on and fader closed on a single source. Source receives PGM 1 minus themselves.
  • Full yellow (Conf audio) = conference on and fader closed on more than one source. All conference members receive the conference bus minus themselves.

Conference System Example

In the example that follows, there are three conference members: Mic 01 (the host), Mic 02 (a studio guest) and Codec 1 (a phone-in guest).

When all three source faders are closed, the Conf keys turn full yellow and the sources receive the conference bus minus themselves. In other words, they can hear each other, but not themselves, and chat off-air.

If you open the Mic 1 (host) fader, the source goes on-air. The Conf key turns full green, to indicate that this source is in "Conf prepare", and the source's N-1 is switched back to a programme mix minus. The other two sources remain in "Conf audio". This allows the studio and phone-in guest to continue their off-air conversation. At any time you can close the Mic 1 fader so that the host can rejoin the off-air conference.

If you open the Mic 1 (host) and Mic 2 (studio guest) faders, then two out of the three sources go on-air. The Conf keys turn full green, to indicate "Conf prepare", and each source's N-1 is switched back to a programme mix minus. In this instance, there are less than two active conference members and so the conference is canceled. The Cdc 1 source's N-1, for the phone-in guest, is switched back to a programme mix minus and its Conf key turns dim yellow to indicate "Conf active".

The image below shows how this looks on the surface.

At any time you can remove a source from the conference by deselecting its Conf key. The key turns dim white and the source's N-1 switches back to a programme mix minus.