Gain / Level Optimization - Lab.gruppen PLM series Operation Manual

12. Application Guide
Input gain
This is used to adjust the level between different cabinets in the system. It should be left at 0 dB unless you
want to lower the level for the cabinet(s) driven by this module (Adjustments made in I/O Config, module
pane).
Module output gain (Levels)
Two points of gain level adjustments are provided per Module output. They are used to balance the mutual
gain between frequency bands in a multi-way set up, and can be described as follows:
▸ Manufacturer gain: This is "hidden" within the module file and is set by the creator of the file. As such, it
is not user editable.
▸ Gain: This is editable by a user. The module file (part of the Fingerprint) contains a default value for this
as well as the manufacturer gain. If the manufacturer gain is set to a non-zero value, then the default gain is
zero dB so that the user can easily see any changes that have been made to this setting. Normally it should
not need to be adjusted by the user.
Output gain (Levels)
One adjustment is provided per output channel in the module to balance the mutual gain between frequency
bands in a multi-way set up. Generally, this setting is derived from the Module file data within the PLM
preset. As such, it should not need to be adjusted further. (Adjustments made in I/O Config, module pane.)
Attenuator
One adjustment is provided per output channel in the PLM. This control replaces the traditional knob found
on conventional amplifiers. It should typically be left at 0 dB during use. (Adjustments made in Lab.gruppen
Info, Status tab).
Amp Gain
Corresponds to the gain adjustment in a conventional system if the amplifier was outside the PLM. It should
retain the same settings as in the module file that is loaded: The limiter and output gain settings in the
output stage of the module were configured with this gain setting and will not be automatically compen-
sated if changes are made. This configuration scheme, though unusual, allows for backwards compatibility
with other Dolby / Lake products. (Set in Lab.gruppen Info, Control tab.)
The following details can assist in setting an appropriate gain structure within the PLM.

12.3.1 Gain / Level optimization

Optimum setting of the PLM gain structure requires particular attention to two matters:
Make sure it can get loud enough.
To do this, the user should ensure that there is sufficient headroom in the signal path to avoid clipping
before signal reaches the limiters. At the same time, it must be possible to achieve enough gain through the
PLM to engage the limiters and realize a high average SPL as a consequence. As an optimal setting, allow
for a headroom of 10 dB or more for all channels. The simplest way to accomplish this is to increase the
input gain on the module.
Minimize the noise.
As a first step, use a digital input signal (AES or Dante) when possible. If using analog inputs, ensure that
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PLM Series Operation Manual rev 1.1.3