Pioneer VSX-9140TXH User Manual

18

As indicated in 

Things you can accomplish with this application (page 3)

, the reverb characteristics graph 

can be used as reference when determining the calibration time position with the receiver’s “Advanced EQ 
Setup” function. It is also a valuable means for checking the effect of measures taken to improve the 
acoustics of the room.

 

The display can be switched between the reverb characteristics graphs before and 

after calibration. For details, see 

calibration (page 23)

.

The graphs show changes in microphone input level along a time axis, beginning from a state of quiet at 
time 0, when test tones begin to be output, and continuing while a constant level of sound is output from the 
speakers.
• If there is absolutely no reverberation in your room, the graph will look like figure A below.
• If there is reverberation, the graph will show a gradual accumulation of acoustic power, as shown in figure B.

• Due to an effect known as “group delay”, lower frequencies may take longer to be generated than higher 

frequencies (this is most obvious when comparing the frequencies around 0 ms).

• If a graph extends beyond the display range, or almost fills it, you can change the display by using the Z 

(Zoom) control on the graph adjustment bar, adjusting the display range of the Level [dB] scale so that the 
whole graph is visible.

• Since channel level and speaker distance settings are displayed in the graphical output, it is best to make 

sure these settings (made in the Auto MCACC “ALL” or “Channel Level” setup) are adjusted properly 
before reverb measurement.

• Even in cases where there is a great difference in the output levels of different frequencies (the frequency 

characteristics of the room are poor), the frequency characteristics of individual channels can be set 
closer to flat using the “SYMMETRY” or “ALL CH ADJ” calibration settings in the receiver’s “Auto MCACC” 
function. (For details, see page 78 of the receiver’s Operating Instructions.)

• It is usually not possible to calculate the equalization values employed by the receiver’s Acoustic Cal EQ 

function simply by viewing the graphs displayed on your PC. (This is because the automatic adjustments 
made by Acoustic Cal EQ function take account of factors such as equalization band interference and 
analytical filter characteristics, to achieve the optimum characteristic profile.)

• There may be differences on the reverb characteristics graphs after measurements with the Full Auto 

MCACC function as compared to after measurements with the Reverb Measurement function (Manual 
MCACC 

 “EQ Professional”) due to the standing wave control setting. With Full Auto MCACC, the 

reverberations are measured with standing wave controlled, so the reverb characteristics graph does not 
reflect the influence of the standing waves. By contrast, with Reverb Measurement, the reverberations are 
measured without standing wave control, so you can check the reverb characteristics including the 
influence of the standing waves. If you want to check the acoustics of the room (with the standing waves), 
we recommend using Reverb Measurement.