TC Electronic LM2 Plug-in - Manual (Page 9)

LM6 - Radar Loudness Meter / 9
EN
Radar Page
Current Loudness: Outer Ring
The outer ring of the Radar page displays Momentary loudness. The 0 LU point (i.e.
Target Loudness) is at 12 o’clock, and marked by the border between green and
yellow, while the Low Level point is marked by the border between green and blue.
The LU Reference parameter are found on the Setup page. For instance, if 0 LU is
set at -22 LUFS, and Low Level is set at -20 LU, the color coding of Fig 3 applies.
You should keep the outer ring in the green area, and around 12 o’clock on the
average. Excursions into the blue or the yellow area should be balanced, and not
only go in one direction.
The numbers associated with the outer ring may be referenced at either maximum
loudness (LUFS selected), or have a zero point set at the 12 o’clock position (LU
selected). Choose “LUFS” or “LU” at the Loudness Scale selection on the Main page
depending on your preference. Either way of looking at loudness is valid. LUFS
reading is in line with how peak level is typically measured in a digital system, and
compatible with Dolby AC3 and E meta-data, while the LU approach calls for a
certain target Loudness to have been predetermined, like e.g. a VU meter.
Note how “LUFS” in some countries is called “LKFS”, but the two are identical. A
reading of, for instance, -25.0 LUFS is precisely the same as -25.0 LKFS.
Long-term measurements
Universal descriptors may be used to make program-duration measurements, or you
may “spot-check” regular dialog or individual scenes as required. It is recommended
not to measure programs of a shorter duration than appoximately 10 seconds, while
the maximum duration may be 24 hours or longer.
Reset Key
Before a new measurement, press the Reset key. This resets the
descriptors, the radar and the true-peak meters. Run the audio,
and watch the radar and descriptor fields update accordingly. It
is normal that the descriptors wait five seconds into the program
before showing the first readings, while the radar updates
instantly. The first five seconds of a program are included in the
descriptor calculations, even though they are not shown instantly.
LM6 incorporates an intelligent gate, which discriminates between foreground and
background material of a program. Consequently, a measure doesn’t start before
audio has been identfied. It also pauses the measurement during periods of only
background noise, and in the fade-out of a music track.
Universal Descriptors and Dolby LM100
Unlike methods that measure dialog only, LM6 may be used with any type of audio –