Yamaha IMX644 - page 22

IMX644 Manager Owner’s Manual 22

4[STEREO 1]–[STEREO 4] check boxes

These turn on/off the Music Override function for each STEREO INPUT channel. These check boxes are linked with the

[OVERRIDE] buttons of the INPUT screen. The default setting is OFF for all channels.

NOTE

• If this is turned on for more than one STEREO INPUT channel, the lowest-numbered channel will take priority, and the volume from

other STEREO INPUT channels will be faded-out.

5Release Time

This specifies the time from when the STEREO INPUT channel’s audio signal disappears until the fade-in returns to the orig-

inal volume.

• Feedback Suppressor

The Feedback Suppressor effectively controls feedback by identifying the feedback frequencies produced by factors such as the

acoustics of the venue and the characteristics of the signal path. The Feedback Suppressor includes static filters that are set based

on analysis of each MONO INPUT channel, and dynamic filters that dynamically suppress feedback when it occurs on the specified

MONO INPUT channel.

By default, the Feedback Suppressor is turned on for all MONO INPUT channels. The static filters are unset.

NOTE

•By default, the Feedback Suppressor is turned on for all MONO INPUT channels. Even though the static filters are unset, the dynamic filters

are still operational so be sure to turn the Feedback Suppressor OFF before using sine waves or test tones to test or calibrate the system.

• Feedback Suppressor settings will be stored in the unit’s 16 memories.

• Static Filter analysis can also be performed from the IMX644’s panel. For details about the analysis procedure on the IMX644, refer to the

IMX644 owner’s manual.

6[MONO 1]–[MONO 6] check boxes

These turn on/off the Feedback Suppressor for each MONO INPUT channel. These check boxes are linked with the [F.B.

SUP] buttons of the INPUT screen.

7[Automatic Setup] button

This consecutively tests each selected MONO INPUT channel and automatically makes the appropriate static filter settings.

To ensure optimum feedback suppression be sure to perform the measurements under the same conditions that will prevail

during actual operation (microphone and speaker positions, etc.).

1. Set up the microphone at least 5 meters away from the speakers.

2. Adjust the output level of the power amplifier.

While speaking or singing into the microphone gradually raise the output level of the power amplifier to the level that will be

used in actual operation. Also make sure that feedback does not occur when you clap your hands near the microphone.

3. Make sure the area being measured is silent.

4. Click the [Automatic Setup] button to begin the measurement.

The dialog box shown at right will appear while the static filter measurement is

being performed. When the measurement is completed, the dialog box will close

and the results of the measurement will be applied to the static filters.

NOTE

• If high-volume sound is produced, an error has occurred during measurement. If this occurs click the [CANCEL] button to abort the meas-

urement. Before performing the measurement again, try changing the location or orientation of the microphone and speakers, lower the

amplifier output, then repeat the procedure from step 1 above.

• If an error message appears, an error has occurred during measurement. To prevent damage to the equipment the measurement will be

aborted and the erroneous data discarded. If this occurs try changing the location or orientation of the microphone and speakers, lower the

amplifier output, then repeat the procedure from step 1 above.

• Static filter measurement may not be successful if the overall level is too high or the microphone is too close to one of the speakers.

Parameter Range Default

Release Time 0.0 – 6.0sec 4.0sec