TC Electronic Radar Meter Bundle TDM - Manual (Page 18)

ENGLISH
16 / LM5/LM5D & AM6
ENGLISH
Meter Calibration
Because of the frequency and channel weighting, and of the way channels sum, only
specific tones and input channels should be used for calibration.
The most transparent results are obtained using a 1 kHz sine tone for calibration.
Other frequencies or types of signal may be used (square wave, noise etc.), but don’t
expect similar results. The beauty of the system lies in its RMS foundation, so this
is a feature, not an error. The same feature enables the loudness measure to identify
overly hot CDs or commercials, and to take out of phase signals into account just as
much as signals that are in phase.
If we stick to standard methods for measuring peak audio level in a digital system,
where a sine wave (asynchronous of the sample rate) with digital peaks at 0 dBFS, is
regarded a 0 dBFS tone, BS.1770-2 and LM5D output these results:
One front channel fed with a –20 dBFS, 1 kHz sine tone => Reading of –23,0 LUFS.
Two front channels fed with a –20 dBFS, 1 kHz sine tone => Reading of –20,0 LUFS.
All 5.1 channels fed with a –20 dBFS, 1 kHz sine tone => Reading of –15,4 LUFS.
PRESETS
LM5D
AM6