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Microphone balance calibration
The microphones supplied with the Realiser are matched by hand at the factory within a fraction of a
decibel. Any slight remaining difference in sensitivity will become part of the HPEQ measurement, so
listening to a PRIR and HPEQ made with the same microphone pair will be fully compensated.
The Realiser provides a microphone balance procedure in order for microphone imbalance to be
compensated independent of HPEQ, so that any PRIR can be used with any HPEQ regardless of the
microphones used. Because the microphones in each pair have already been carefully matched, this
procedure may be superfluous, but it provides further assurance that any residual imbalance, effect of
microphone aging or mishandling, etc. is accounted for.
Place the microphones close together and stationary. Diffuse ambient sound is best for this
measurement. Only after the microphones have been placed, press
MENU-CAL
. The screen will say:
MIC CALIBRATION
BALANCE: 1.0 (L/R)
PRESS EXIT TO ABOUT
...OK TO REBALANCE
While this menu is on screen, the Realiser is accumulating the average signal level received at each
microphone. When
OK
is pressed, the balancing factor is calculated and the accumulators are reset.
After perhaps fifteen seconds, press
OK
and observe the number. Do this several times and you should
see similar numbers each time. After several brief observations, let the measurement accumulate for
several minutes and press
OK
. This final, longer-accumulated factor will be the one to use. If during
the brief trials you get very different numbers each time, check the cabling and try to avoid loud
transient sounds during the measurement.
The range of factors is
0.5
to
2.0
, with
1.0
indicating that no compensation is necessary.
Intermediate readings will be compensated, but a reading of
0.5
indicates 0.5 or lower and a reading
of
2.0
indicates 2.0 or higher, so if either of these numbers appears, it should be considered that there
is a problem with the microphones.
The last-calculated factor will be applied for new measurements until power-down; to save it for future
sessions, press
(!)-SAVE SYSTEM CONFIG
.
Microphone pass-through
While the
MIC CALIBRATION
screen is active (
MENU-CAL
), the microphone input is routed to the
headphone output. Press
CANCEL
to end the connection. By listening to the headphones and lightly
touching the microphones, you can verify that the microphones are “live”. This can be an aid in
identifying any problems with the microphones, the mic cables, the Y-connector, full insertion of all
microphone plugs, etc.
Display refresh
If a power surge or interruption, or another factor causes the display to blank or show “garbage”,
pressing
0
may restore the correct screen.
Display contrast
The LCD screen of the Realiser can be adjusted for best readability at various viewing angles. Press
MENU-0
. The display will say
DISPLAY CONTRAST ADJUST
. Use the ^ and
v
keys to adjust the
