Connection Panel

Equalizer

The seven-band equalizer allows you to shape sound to taste, accommodate sources with different acoustic characteristics, minimize feedback or roll off unwanted parts of the audio spectrum.

Enable or disable the Equalizer using the switch beside the label above its control group. The vertical sliders attenuate or boost the tonal range centered on the frequency shown at the top. The effect applied falls off gradually as sound draws closer to neighboring frequencies on either side. Click Reset to return all sliders to 0dB.

Compressor Limiter

The Compressor/Limiter is capable of preventing clipping (see Output and Primary Bus Controls) from unexpected peaks or transients, and making talent sound better, bringing voices, music and other audio sources into an optimal dynamic range.

Compression takes the form of a subtle, almost imperceptible modulation of the sound level to bring it into a more convenient range, and a limiter is essentially just a compressor set to a high ratio and, generally, a fast attack time. Audio engineers typically consider compression with a ratio of 1:1.

• Threshold: Sound above the set Threshold level is compressed. The amount of compression and the manner in which it is applied are both dictated by the other settings.

• Ratio: A Ratio of 4:1 means that if input level is 4 dB over the threshold, the output signal level after compression is just 1 dB over the threshold. The gain (level) is reduced by 3dB. Very high ratio settings are the reason the word limiter is part of the label for this feature. The highest ratio setting effectively reduces any signal that would rise above the threshold all the way down to the threshold level (with the exception of a brief period during a sudden increase in source loudness, as dictated by the Attack setting).

• Attack: Attack is also in milliseconds. The setting represents the amount of time it takes for the gain to change by a specified amount. Shorter values are more aggressive, while longer values are more subtle (and tend to be less noticeable to the audience).

• Release: Refers to the speed with which the compression effect is removed as a source signal falls back on its own so that it no longer exceeds the Threshold.

• Makeup Gain: The Gain control allows you to compensate, bringing the post-compressor/limiter signal back to a comfortable nominal range.

Noise Gate

The Audio Mixer’s advanced options panel also include a configurable Noise Gate for each audio source, as well as all outputs. This lets you ensure that unwanted low-level sounds are prevented from inadvertently intruding into the mix.

Neutral Voice Isolation

Used to enable and disable noise reduction.

• Check the Neutral Voice Isolation box and select your channel(s). The AI audio can be individually selected for each channel of an input.

Triggers

Several different per-input automation features are found in the Processing tab.

• Follow Program Video: Enable this option for an audio source, directs it to track switcher operations affecting the related video source. Audio for sources with Follow Program video enabled in the Audio Configuration panel, is automatically removed from mixed outputs until one or more specified video sources are actually displayed on Program Output.

• Run Macro at: Is part of the Audio Mixer’s powerful automation toolset. Click the E button to assign macros to run when the sound level for the input passes the threshold audio level.

Busses and Outputs

Advanced mixers often provide more than one send for individual inputs. For example, the sound from all inputs may be sent to the master bus, comprising the master mix. A different mix, sometimes called a sub-mix, might also be created by sending certain signals to a secondary (auxiliary, or Aux) bus.

The Audio Mixer provides four primary audio busses. These are identified in the Audio Mixer as:

• Master

• AUX 1, 2 and 3

The Audio Mixer provides controls for each of these busses, allowing you to manage levels and signal processing. It is important to understand the distinction between busses and outputs.

An output may be physical, or virtual (it may involve a connector on the rear panel, or not). For example, audio recorded internally does not require an output connector. Likewise, it may initially be analog or digital.

Sub-Mixes and Mix Minus

Specialized sub-mixes of this sort are often referred to as mix-minus, since one or more sources are deliberately subtracted from the mix. Mix-minus capabilities can be invaluable for productions like phone-in shows.
This eliminates annoying echoing, feedback and the like. Also important, independent control and signal processing is provided for each part of the pipeline.

Mix Minus for External Audio Devices

The Routing tab provides 8x8 matrix routing panels for each input, allowing for more sophisticated mixes than the example above. Viz Vectar Plus supports eight channel NDI output, so it is possible to route a unique mono mix-minus on each of these channels for an Aux bus. Thus, a single NDI a/v output stream can provide all of the mix-minus needed for up to eight external callers.

For example, if you configured Switcher inputs 13-16 to receive audio from four unique remote callers, video MIX 2 can be used to supply Program video to each caller (if the equipment supports video return). AUX 1 is configured as the Audio source for MIX 2, then assign a unique (mono) mix minus to four of its channels to supply return audio for each caller.

• In the Output Configuration panel, assign Aux 1 as the Audio source for MIX 2.

• In the Audio Mixer, open the audio configuration pane for Input 13.

• Access the Routing tab and click the Clear button above the Aux 1 routing matrix.
  

  

• Check channels 2, 3 and 4 in the column below In 1. This routes sound from the first incoming caller to all Aux 1 output channels except channel 1.

• Open the audio configuration pane Input 14 and, in the Routing tab, clear the Aux 1 matrix.
  

  

• Check channels 1, 3 and 4 in the column below In 1. This routes sound from the second incoming Skype caller to all Aux 1 output channels except channel 2.

• Repeat the steps above for audio inputs 15 and 16, omitting the Aux 1 checkmarks under In 1 for channels 3 and 4, respectively.

This is a mix minus configuration for return to four callers, using a single NDI output.