A
NTI
-M
ODE
8033C
INEMA
3. Wider Area Correction
In some situations it is more favorable to compensate for room acoustics in a wider listening
area. When this is done, the result is no longer optimal in any single listening position but is
improved for a wider listening area. Before performing wider area correction the first (main)
calibration procedure described in the earlier section must be performed. As previously
discussed, the first calibration is done with the microphone at the center of the listening area
or primary listening position within the area.
The Anti-Mode 8033 can be calibrated for wider areas by moving the microphone to another
point within the listening area. Pressing and holding the BYPASS button will initiate a
secondary calibration utilizing two to three additional frequency sweeps. The Anti-Mode 8033
will use the results from these sweeps in conjunction with data gathered from the first
calibration to create a compensation model for a wider listening area.
Do not accidentally keep both the LIFT and BYPASS buttons pressed on the front panel as
this will start the first (main) calibration all over again overriding the current room data.
Secondary calibrations can be done multiple times and will not result is the loss of data from
the first (main) calibration. The previous secondary calibrations will not be retained. It is easy
to try different secondary calibration points for the best audible result. Following are several
strategies for choosing the microphone position for the secondary calibration.
3.1. Strategy 1, “Compensation of the worst response point”
When the first (main) calibration is performed at the primary listening position or at the
center of the listening area, you can then evaluate the result by listening at different positions
around the room.
If the result is not adequate at some location, that location can be used as a secondary
calibration point. Also any location between the secondary point and the first point can lead
to good results. Inevitably, the result will get less optimal at the first point, but is usually
improved everywhere else, including the worst response point.
3.2. Strategy 2, “Gradient compensation”
If it is difficult to find the worst response point in the listening area, Gradient compensation is
a good approach. Find the secondary calibration point by moving the microphone from the
first calibration point toward the closest corner of the listening room by 40-90 cm (16 to 36
inches) and downwards (towards the floor) approximately 10-20 cm (4 to 8 inches).
Perform the secondary calibration with the microphone in this position. If the first calibration
point was closer than a meter (39 inches) from the wall, the microphone should be moved
only about 20-40 cm (8 to 16 inches) towards that wall for the secondary calibration.
The Gradient compensation method works well in removing the resonances arising from
reflections between opposing walls or floor/ceiling (axial modes) for larger areas in a
rectangular room.
Rev. 1.9
2012-03-20
Page 8 (12)
