Lab.gruppen PLM 20K44 Operation Manual page 82

10. Application Guide
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
• Absolute Noise Floor: -71.3 dBu
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
Table 10.6: Analog Input: Moderate Noise with Very High Output (Very High SPL)
10.4. Speaker Configurations
impedance of that presented by one speaker. Therefore, the current that two speakers will attempt to draw from
Limiter to become active. The more speakers connected to an output in parallel, the lower the impedance and the
higher the current draw.
Multiple loudspeakers may be driven by a PLM+ power output more satisfactorily if a series-parallel wiring
When using series-parallel wiring, the nominal impedance is the same as with one speaker; however, the principle
of power sharing still applies, and it is not possible to get t
NOTE: Nominal loads as low as 2 ohms are supported by the PLM+. However, a 2 ohm nominal load
has impedance dips at its resonances below 2 ohms; in such cases it is likely that the resulting higher
current will cause CPL to activate.
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PLM+ SERIES Operation Manual rev 3.0.1
Input Mixer Module In Module Out Amp Attenuation Analog Ref Amp Gain ISVPL
Clip
Nominal
Noise
Output