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SECTION 3.13 CONFIGURE AUDIO

Click the Audio Mixer tab (centered in the lower third of the Live Desktop) to reveal audio features, including configuration controls for all internal and external audio sources, IsoCorder™ recording levels, and outputs - including streaming.

FIGURE 27 (8-INPUT VERSION SHOWN)

Each input has its own small control panel, with Volume slider(s), VU meter(s), and other important features conveniently located. At the top of each of these control panels is a label. Roll the mouse pointer over the label to reveal a gear button at right which, when clicked, opens the Configuration panel (Figure 28) for the input.

This panel holds advanced audio features as well as basic setup controls. After connecting audio sources to the input connectors (see also Section 3.5.1), the first thing to do is set the correct Connection Type using the drop-down menu:

 Select Mic 1, 2 for professional grade microphones or similar sources. Use the Phantom option for condenser type microphones requiring supplementary power.

 Choose Line for most other device connections (including consumer devices such as a CD player, computer audio output or VCR).

 For 8-input models only, select AES/EBU for digital audio from an AES/EBU (AES3) output.

 SDI Embedded or HDMI provide digital audio from the associated video connection.

Note: Analog audio levels conform to SMPTE RP-155. The maximum input/output level is +24 dBu, nominal Mic input level +4 dBu (-20dBFS), and the sample rate is 96 kHz.

The Volume sliders (next to the VU meters) default to their lowest settings on first launch. After adding audio sources, slowly bring these sliders up to pass their signals through the system.

Hint: Most numeric controls in TriCaster can be reset to their defaults using Shift + double-click on the control knob. The default value for Gain sliders is 0dBVU.

Some variation exists as respects signal levels from individual sources, even within the same type. For Mic (and Mic + Phantom) connections, Gain (a.k.a., Trim) controls are provided to allow fine tuning of the input level.

To access these controls, open the Advanced Audio

FIGURE 30

Configuration panel, by clicking the Configuration button (gear) in the titlebar for an input control group. Use the Gain knobs (Figure 30) to bring the levels for microphones and similar sources into a useful range on the VU meter.

AUDIO HEADROOM

In digital audio systems, levels exceeding ‘legal’ values are ‘clipped’ (uniformly assigned the maximum value). This results in audible issues that cannot be easily corrected later.

For this reason, it’s customary to configure normal operating level (also referred to as the ‘alignment level’, and sometimes, ‘nominal level’) well below the clipping limit – sufficiently so that occasional excessively loud sounds (say, loud laughter or applause) can be accommodated without risk.

This range above between nominal level and the highest possible level is commonly referred to as ‘audio headroom’. What is considered a suitable headroom allowance can vary from one locale to another, in different industry applications, and even in individual studios.

TriCaster’s audio controls follow well-established conventions, providing 20dB of headroom above nominal level (+4dBu at 0dB on the VU scale).

Hint: Confusion can sometimes arise because different calibration scales are common in various audio realms, and even for different device types and software.

FIGURE 31

For example, analog mixers commonly show levels on VU scales indexed as just described. In contrast, digital devices and editing software usually display levels in dBFS (Decibels Full Scale), with 0dBFS – the absolute maximum allowable signal that can be recorded – at the top of the scale.

TriCaster’s VU meters have selectable indexing, allowing you to view a traditional dB VU scale or dBFS as you please (see Section 15.8.1).

Whatever scale you choose, use Volume controls (and, for Mic connections, the Gain

controls in the Configuration panel) to avoid over-modulation.

TriCaster’s Compressor/Limiter feature (also located in the Advanced Audio Configuration pane) is another powerful tool to help you prevent clipping – see Section 15.7.

SECTION 3.14 CONFIGURE GENLOCK

Genlocking is supported on TriCaster 460, 860 and 8000.

1. If the Live Desktop isn’t already open, launch a TriCaster session from Startup.

2. Access the Output Configuration panel by double-clicking the main Program Output monitor on the Live Desktop.

3. Click the Genlock & Failsafe tab (Figure 32).

4. The default Reference Type in the Genlock settings group is SD (Bi-level), as this is currently the most common reference signal type. However, if you supply an HD reference signal to the Genlock input, you may want to change the setting to HD (Tri-level).

5. With the aid of downstream Waveform and Vector Scopes, adjust TriCaster’s Horizontal and Vertical Position and Phase settings in the Genlock section of the I/O Configuration panel.

FIGURE 32

Ideally both the cameras and TriCaster should be genlocked. If they are not genlocked to the same reference signal as the TriCaster output, a TBC (Time Base Correction) operation is automatically applied. Time base correction may drop or insert frames as necessary to maintain sync, hence is a less desirable approach.

Note: For a deeper discussion of genlocking, please see Section 8.1.2.

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