Pioneer VSX-921 - Manual (Page 15)

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How to Interpret the Graphs (Continued)
Deciding the time period for Advanced EQ Setup calibration
With conventional MCACC EQ calibration, the microphone input’s data acquisition time was fixed at
between 80 and 160 [ms] (red part of Figure 1). By contrast, with the receiver’s Advanced EQ Setup function
allowing more professional equalization, the customer can select individual points between 0 and 80 [ms]
(with a 20 ms width) (blue part of Figure 1).
You can specify the time period setting using the “Advanced EQ Setup” in the “EQ Professional” sub-menu
(in the “Manual MCACC” menu). This setting is not required if you’re satisfied with the results of the “Full
Auto MCACC” setup (For details, see the receiver’s Operating Instructions).
Figure 1: Comparison of microphone data acquisition time periods
To decide the time period for Advanced EQ Setup calibration, view the graphs of the measured reverb
characteristics, and refer to the following three patterns.
Pattern 1: Different reverb characteristics for high and low frequencies
In rooms with reverb characteristics like those shown in Figure 2, lower frequencies often seem overly
reverberant compared to higher frequencies (i.e. the room sounds ‘boomy’). With conventional MCACC EQ
calibration, data between 80 and 160 [ms] (red part of Figure 2) was acquired, so the low frequency volume
was deemed high and the high frequency volume deemed low, and the equalization curve was calibrated
with the high frequencies somewhat boosted. However, for the characteristics of the sound reaching the ear
directly within about 40 ms, there is enough volume that there is no real need to boost the high frequencies,
so with equalization using the conventional MCACC EQ calibration the high frequencies sometimes
sounded too strong. Therefore, the Acoustic Cal EQ may result in a room where high frequencies sound
shrill. In cases like this, setting the time period for Advanced EQ Setup to 30 to 50 msec (the blue area
in Figure 2) to adjust for sounds coming directly from the speakers can flatten the frequency response
for direct sounds (including initial reflections) and give a better-balanced sound field.
Figure 2
Note
Level
(dB)
Conventional MCACC EQ
calibration time range
(fixed)
Time (in ms)
EQ calibration time range
selectable for Advanced
EQ Setup function
(selected automatically for
Full Auto MCACC)
Level
(dB)
Time period
point to be
selected
Time (in ms)
Low frequencies
High frequencies
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