Lab.gruppen PLM series Operation Manual page 91

▸ Absolute Noise Floor: -71.5 dBu
▸ SPL is limited to -8.9 dB relative to clip in this minimum absolute noise level example
60,0
40,0
20,0
0,0
-20,0
-40,0
-60,0
-80,0
-100,0
-120,0
-140,0
Analog AES Input
Figure 10-4: Analog: Low Noise with Limited Output (Low Input / Low SPL)
Figure 10-5 illustrates how to minimize absolute noise while achieving full power. In this illustration it can be
seen that there is no available headroom.
▸
Input Clip: 12 dBu
▸ Amp Gain: 30.9 dB
▸ SNR: 111.3 dB
▸
Absolute Noise Floor: -68.4 dBu
80,0
60,0
40,0
20,0
0,0
-20,0
-40,0
-60,0
-80,0
-100,0
-120,0
-140,0
Analog AES Input
Figure 10-5: Analog: Low Noise with Full Output Power (Low Input / High SPL)
Figure 10-6 illustrates how moderate noise with extreme SPL can be achieved. SPL is extremely high in
this example as maximum headroom is available at the input and within the processing stage. This makes it
possible to increase the average SPL by utilizing internal compression capabilities.
▸
Input Clip: 0 dBFS
▸ Amp Gain: 35 dB
▸ SNR: 114.2 dB
Input Mixer Module In Module Out
Input Mixer Module In Module Out
Amp Attenuation Analog Ref Amp Gain
Amp Attenuation Analog Ref Amp Gain
PLM Series Operation Manual rev 1.1.9
Application Guide
Clip
Nominal
Noise
ISVPL Output
Clip
Nominal
Noise
ISVPL Output
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