Linear Acoustic UMPAX v4, User Manual

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Linear Acoustic UPMAX v4 User Guide Applications
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3.1.1 General Notes
The latency of the UPMAX v4 has been kept as low as possible. To take best advantage of
this, make sure it is installed in a synchronous system (i.e. as a send and return to a console)
and set the Sample Rate Converter Bypass to ON (i.e. SRCs are off). This will keep the
latency at around 4msec. Make sure to take care not to bring up both the send and return
audio else even this very low 4msec might cause comb filtering.
In general, an upmixer responds to level to control Left to Center to Right positioning, and
phase to control front to back positioning. UPMAX v4 operates across multiple bands to
minimize low frequency content causing center channel build-up. However, dialog can do
the same thing, especially announce dialog. It was discovered some years ago that simply
separating a mix into two parts: Main Stereo (no announce) and a separate Announce chan-
nel then upmixing only the Main Stereo and combining with a time aligned version of the
Announce audio produces a very wide and stable result free of odd sounding artifacts.
3.1.2 Two-Channel Interstitial Programming
One of the largest complaints viewers is the annoying fact that stereo commercials don’t
seem to “fit” into the 5.1-channel program. This is because in many cases, the commercials
are simply transmitted on the Left and Right channels of a 5.1-channel program. The net
result is that during the program, dialogue comes from the center speaker, but at commer-
cial or station breaks, all of the dialogue comes from the left and right speakers. It can be
a jarring experience.
The first application is one where the UPMAX v4 processes the stereo material allowing
it to fit nicely within a 5.1 channel program. Figure 3-1 shows this scenario. Note that the
two channel material is simply input to the UPMAX v4 and a 5.1 channel signal is available
at the output. Either of the
Commercial or Music presets can be chosen, and are ex-
plained in detail at the end of this chapter.
3.1.3 Sports Production
Sports production could be as simple as creating an excellent and wide stereo mix with di-
alog on a separate bus. Using the UPMAX v4, the stereo mix can be turned into 5.1 and
the announce audio passed around the upmixer.
A Center Detect control was added to the Auto mode to facilitate handling this type of 3-
channel audio. It ignores the presence of audio on channel 3 (i.e. the announce audio), time
aligning it and summing it with the upmixed version of the audio from input channels 1-2.
This mode is also useful if the audio might be of several different flavors. With Center De-
tect set to off, Stereo, 3-channel, and 5.1 channel input audio can be automatically handled
with no operator intervention. A tip would be to adjust the crossfade timing to be as fast
as practical.