10. Application Guide
PLM+ SERIES Operation Manual rev 3.0.1
81
The improvement in noise performance (at the cost of losing headroom and compression features) is only 0.6 dB;
it is therefore not recommended to optimize performance in this manner.
10.3.3.2. Analog Input Gain Structure Examples
Figure 10.4 illustrates how to minimize absolute noise while limiting the available SPL. Input Clip: 12 dBu
•
Amp Gain: 22 dB
•
SNR: 105.5 dB
•
Absolute Noise Floor: -71.5 dBu
•
SPL is limited to -8.9 dB relative to clip in this minimum absolute noise level example
Table 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
Table 10.5: Analog: Low Noise with Full Output Power (Low Input / High SPL)
-140,0
-120,0
-100,0
-80,0
-60,0
-40,0
-20,0
0,0
20,0
40,0
60,0
Analog
AES Input
Input Mixer
Module In
Module Out
Amp
Attenuation
Analog Ref
Amp Gain
ISVPL
Output
dB
/d
B
u
Clip
Nominal
Noise
-140,0
-120,0
-100,0
-80,0
-60,0
-40,0
-20,0
0,0
20,0
40,0
60,0
80,0
Analog
AES Input
Input Mixer
Module In
Module Out
Amp
Attenuation
Analog Ref
Amp Gain
ISVPL
Output
dB
/d
B
u
Clip
Nominal
Noise
