Cobalt Digital COMPASS 9085 Loudness Processor - Manual (Page 16)

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9085 Functional Description
1-12 9085 PRODUCT MANUAL 9085-OM (V4.3)
Audio/Video Delay Offset
The 9085 includes an audio/video delay offset function that allows audio/
video resyncing to compensate for an 8 msec delay induced by the loudness
processing function. Ideal resync of audio is provided by advancing the audio
8 msec using this function.
Note: Although similar to a framesync function, the audio/video delay has significant
limitations (as compared to a full framesync function) which should be consid-
ered when setting up and using this function. These considerations, along
with the proper setup to use the 9085 audio/video delay function, are fully
described in Chapter 3. Operating Instructions.
Audio LKFS Monitor Description
Note: Refer to Appendix A, “Loudness Measurement Guidelines and Techniques”
for more information about LKFS parameters and this function, as well as
practical measurement techniques.
This function monitors selected output (“destination”) channels from the
Audio Routing/Gain Control function and applies signal analysis based on
ITU-R BS.1770-1 – ATSC A/85 criteria to produce an LKFS measurement
and provide indications of under-threshold and over-threshold level
conditions.
The function can monitor any combination of embedded, AES, or analog
channels selected as the L, R, C, Ls, and Rs ITU-R BS.1770-1 channels (note
that the LFE and AUX channels are not included in any LKFS calculations).
Because the LKFS monitor uses output (post-processed “destination”)
channels, LKFS values displayed are post-loudness processed values.
The functions provides a configurable moving average period for tailoring the
measurement to suit various program material conditions.
Tone Generator Function
The 9085 contains four built-in tone generators (Tone Generator 1 thru Tone
Generator 4). Each of the four tone generators can be set to a different
frequency, and are available as audio sources for the embedded or AES audio
outputs.
18 discrete sine wave frequencies are available, ranging from 50 Hz to 16 kHz
(default frequency is 1.0 kHz).