Lectrosonics DM812, Reference Manual, Page: 7 / 51

Reference Manual
Rio Rancho, NM
7
Input Processing
Each input channel provides individual stages for gain,
delay, filtering and compression. (See Typical Input
Signal Processing Blocks .) Processing levels can be
set up with the front panel LCD or with the software GUI
provided with the units. (Details on the signal process-
ing stages are available in the Help available with the
LecNet2™ software.) There are 16 Input Processing
Blocks in the DM1624F and DM1612FF and eight in the
DM812.
Input Gain
The input preamplifier applies software controllable gain
with both analog and digital components, with the ratio
between them automatically optimized for maximum
signal to noise ratio. A single control point is provided
to simplify setup. A level indicator and clipping indicator
are provided in the GUI display.
Delay
A digital delay follows the input stage. A delay of up to
1 second can be applied in 0.5 ms increments.
Filters
Six digital filters are provided to compensate for differ-
ences between various microphones and other audio
sources.
ADFE Filters
Six ADFE (automatic digital feedback eliminator) filters
are provided on each input to suppress acoustic feed-
back that may occur. Applying ADFE at the input rather
than at the output allows the filters to deal exclusively
with the unique characteristics of the individual input
channel rather than with the composite of multiple chan-
nels that appear at any one output.
Compressor
A sophisticated compressor stage is provided following
the other stages to control the dynamic characteristics
of the input. The compressor provides control over
threshold, compression ratio, plus attack and delay time
constants.
Digital Matrix
The digital matrix provides signal routing and commu-
nication with other devices in the system, and applies
automatic mixing and level control. (See Digital Matrix
Functional Block Diagram .)
Automixer Cell
The Automixer Cell is the core of the matrix. It is where
level control for the automatic mixing algorithm, mixing
mode and crosspoint gain is applied to data gathered
from other channels and devices. The cell receives
data from the master unit in a multiple unit stacked
configuration and from the slave units farther down in
the chain.
Typical Input Signal Processing Block
+
Automixer
Cell
Submix
Submix
Crosspoint Gain
-70 to 20 dB
1 dB steps
Mixing Mode
- Auto
- Direct
- Override
- Background
- Phantom
Audio Input
Power of the Mix
Power of the
Submix
Power of the
Submix
Digital Matrix Functional Block Diagram
(Typical Matrix Crosspoint)