How to Interpret the Graphs (Continued)
Pattern 2: Different reverb characteristics for different channels
When different channels can have different reverb characteristics, as shown in Figure 3, it is not so effective to calibrate using the Acoustic Cal EQ. In general, a sound field with good acoustic positioning and movement is made up by sounds coming directly from the speakers (including initial reflections). This is the reason why you should use a calibration method that enables you to adjust direct sounds. In pattern- 2 cases, the Acoustic Cal EQ is not able to adjust frequency characteristics for sounds coming directly from the speakers. It acquires data in the 80 to 160 msec range (the red area in Figure 3.), so its adjustment ability is limited to sounds 80 msec or longer. In cases like this, you should use Advanced EQ
Setup and set the time period to 30 to 50 msec (the blue area in Figure 3). This allows the characteristics of direct sounds to be balanced for each channel, giving an ideal sound field with good acoustic positioning and movement.
Figure 3
Front left channel
Level (dB)
Front right channel
Time period point to be selected
Time (in ms)
Pattern 3: Similar reverb characteristics for high and low frequencies and all channels
As shown in Figure 4, when the reverb characteristics for all channels are similar across all frequencies, your sound experience will probably not be adversely affected by reverberation. Instead of Advanced EQ
Setup, we recommend that you use the “Acoustic Cal EQ” setting from the “Auto MCACC” option menu. This produces a total calibration for both direct sounds and reverberations, resulting in an ideal sound field.
(See page 34 to 35 in the receiver’s Operating Instructions.)
Figure 4
Select the Acoustic
Cal EQ.
Level (dB)
Notes
Front left low frequencies Front right low frequencies Front left high frequencies Front right high frequencies
Time (in ms)
•If you are not sure which time period to specify in Advanced EQ Setup, start by trying 30 to 50 msec. If the graphs show an unusual reverb curve for a specific frequency, the cause may be some accidental variation. Instead of selecting 30 to 50 msec, try another time period.
•Another good method is to try various time periods in Advanced EQ Setup and select the one which sounds the best.
•Time period settings cannot be made on the PC. They can only be made on the
16
