Pioneer MCACC ADVANCED VSX-23TXH Manuel d'utilisateur télécharger pdf (Page 18)

How to Interpret the Graphs

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 About the display of the reverb characteristics graphs before and after

calibration

(page 23)

How to interpret reverb graphs (Reverb)

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.

Note

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Pioneer MCACC ADVANCED VSX-23TXH Manuel d'utilisateur Page 18