LM 128P
Loudness and Peak Program Meter according to EBU R 128
10
SSB AUDIO GmbH * Sonnenweg 25 * 30827 Garbsen, Germany
Tel.: +49 5131 464272 * www.ssb-audio.com * [email protected]
The background brightness can be adjusted by pressing the
BRIGHT
key a second time again for a
minimum time of 800 ms.
G
◄─►R
With this setting the tint of the LEDs set as yellow can be changed between red and green resulting in
further variations for the color schemes. Particularly for color pattern 6, where all LEDs are yellow, the
user may select his preferred monochrome tint for the LED bar between green, different variations of
yellow up to red.
5.7
Reference Level Settings and Clip Indication Time
Attention: For correct measurements the Reference Level Settings must be set correctly. Wrong settings, e.g.
accidentally misadjusted settings, lead to hardly noticeable false measurements!
These three settings are initiated by pressing the
LM/PPM
key together with the
IN
key for a
longer time (minimum 800 ms). All three blue keys start flashing. Now the desired setting is
selected by pressing the corresponding blue key for a short time whereby the selected key starts to flash inversely.
The three keys now work as ‘Up’ (
▲
), ‘Down’ (
▼
) and ‘Exit’ (
▌
) keys.
5.7.1
LU Reference Level
The LU reference level for the measured LU (Loudness Unit) value can be set between -30 LUFS and 0 LUFS in
steps of 1 LU. According to the EBU R 128 this setting shall be -23 LUFS for the EBU Mode. With a setting other
than -23 LUFS the LM 128P will no longer work in the EBU Mode.
The LU reference level can be changed after pressing the
LM/PPM
key together with the
IN
key for a longer time
(minimum 800 ms) followed by pressing the
STL
/
COLOR
key shortly. During setup the numerical display shows
the LU reference level as LUFS.
5.7.2
ADC Full-Scale dBu-Level
When the LM 128P is equipped with an ADC the analog input’s gain can be adjusted in 25 steps of 1 dB each so
that the digital full-scale value is between 0 dBu and +24 dBu.
Example: A setting of 18 means that an analog signal of +18 dBu is converted to 100% FS. In other words, a sine
signal of +18 dBu and 1 kHz applied to both inputs L and R results a measured value of 0 LUFS and a
sine signal of +9 dBu is displayed as a peak program value of 0 dB. (This setting corresponds to the
standard reference level of the ITU-R BS.645-2).
Standard settings are:
Recommendation
Full-Scale dBu-Level
Setting
Analog Level
resulting in
Digital 100% FS
Nominal Level resp.
Permitted Maximum Level
0 dB
Alignment Level
–9 dB
ITU-R BS.645-2
18
+18 dBu
+9 dBu
0 dBu
ARD HFBL-K
15
+15 dBu
+6 dBu
-3 dBu
The ADC full-scale dBu-level can be changed after pressing the
LM/PPM
key together with the
IN
key for a longer
time (minimum 800 ms) followed by pressing the
INT
/
BRIGHT
key shortly. During setup the numerical display
shows the ADC full-scale dBu-level in dBu.
5.7.3
PPM Reference Level
The PPM reference level is fixed according to IEC 268-10/1 so that an input signal of -9 dB FS is displayed at 0 dB
on the PPM scale.
5.7.4
Clip Indication Time
The clip indication time is the time during which the word ‘
CLIP
’ is displayed in the numerical display after
clipping of a digital audio signal has been detected. It can be set to 0.2 – 0.3 – 0.5 – 0.7 – 1.0 – 1.4 – 2.0 – 3.5 –
7.0 - 10 seconds. It also can be set to ‘
OFF
’ which indicates that no clipping is displayed. Additionally it can be
set to infinite (‘
On
’). In this case the display must be cleared manually by either of the three blue keys
(
STL
,
INT
or
LRA
).
The clip indication time can be changed after pressing the
LM/PPM
key together with the
IN
key for a longer time
(minimum 800 ms) followed by pressing the
LRA/G
◄─►R
key shortly. During setup the numerical display shows
the clip display time in seconds resp. the settings ‘
On
’ or ‘
OFF
’.
