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Hint: When the corresponding video source is not displayed on output, the audio source’s VU meter level
is displayed as a grayscale.
R
UN
M
ACRO AT
The nearby Run Macro at (value in dB VU) is part of TriCaster Advanced Edition’s powerful automation
toolset. Click the E (Event) button to assign macros to run when the sound level for the input passes the
threshold audio level (transients such as a brief cough are filtered out).
In this manner you could, for example, automatically perform a ‘hands-free’ camera switch to show someone
who begins speaking, and then automatically switch back again when he stops.
SECTION 15.8
OUTPUT AND PRIMARY BUS CONTROLS
As has been discussed (Section 15.7.2), TriCaster provides four primary audio busses – Master and Aux 1-3.
Each of these is represented by its own control group Audio Mixer’s output section, and regulates sound sent
to physical connectors or to ‘logical outputs’.
Hint: Shift + double click Volume knobs to restore their default values (0dB).
Settings in all of the control groups in this section take effect downstream from all audio sources, further
modulating and processing audio sent to outputs as the Aux and Master mixes, for recording, and for Internet
streaming.
15.8.1
HEADROOM NOTES
In digital audio systems, signal levels that exceed maximum values are uniformly assigned the
maximum value, a condition known as “clipping”. Clipping inevitably results in annoying
audible issues. Worse, over-modulation that may not be apparent while listening during live
production may nonetheless appear in recorded files. This is often true even when levels
appear to be below the ceiling level (0dBFS, the maximum allowable digital level).
Hint: TriCaster Advanced Edition notifies you when clipping has occurred by temporarily turning
the label for the problem channel red, as seen in Figure 15-12.
Due to this problem, digital audio system designs customarily allow substantial ‘headroom’ above the
benchmark ‘alignment level’, making over-modulation much less likely. Often this allowance seems high to
those familiar with analog audio systems; headroom levels between 18 and 24dB are not uncommon in
professional digital audio realms.
TriCaster allows for any preference in this regard, by its provision of separate Record (and Stream) level
controls discussed shortly. For example, Record levels set at -20dBFS (set in the Record Configuration panel)
approximates typical professional practice. This has no impact on levels at TriCaster’s audio outputs, but all
but ensures clipping in recorded files will be avoided.
Advanced users can thus record files conforming to regional standards or personal preference, substantially
reduce the possibility of audio clipping in recorded files, and even adjust the level on the fly if necessary.
FIGURE 15-12