Toa TS-910 Series Manual - Manual (Page 31)

31
9. IF ACOUSTIC FEEDBACK OCCURS
An annoying screeching sound may be produced when using a public address system. It is referred to as
"Acoustic feedback*" that will occur at various frequencies depending on the surrounding environment.
The TS-910's built-in Feedback suppressor (FBS) function effectively suppresses acoustic feedback through
simple operation (depresses the volume level at the feedback frequency). If the built-in FBS function cannot
deal with the acoustic feedback, an external graphic equalizer (prepare separately) can be used for more
effective feedback suppression.
Note
The following measures against acoustic feedback are effective for suppressing feedback only caused by the
Conference unit, but not effective for the feedback caused by the external microphone.
If acoustic feedback stops by fully turning down the volume of the external microphone, you will find that the
external microphone is the cause of the feedback.
In this case, decrease the external microphone's volume to a level that feedback does not occur or use the
external microphone away from the speaker.
* It will occur when a feedback loop is formed in the process that sound from a speaker is picked up by a
microphone, re-amplified, and output through the speaker.
9.1. Using the Built-in FBS function
To perform the FBS function, use the FBS switch and FBS control knob.
When using the built-in FBS function, perform it in automatic operation
mode first.
Note
If acoustic feedback cannot be suppressed with the built-in FBS
function, widen the distance between the Chairman unit and Delegate
units, reduce the output volume, or use an external graphic equalizer.
(Refer to p. 32.)
9.1.1. Using in automatic operation mode (AUTO mode)
Set the Feedback suppressor switch to the AUTO position.
The FBS function automatically searches a frequency that will cause
acoustic feedback and suppresses the feedback by decreasing the
volume level at such frequency.
Step 3. Terminate voting.
Again hold down the Voting Start/End button on the Central unit
for 1 second or more or alternatively the Chairman unit’s Talk
key.
Voting operations from the Conference units are confirmed
and Voting Status indicators [1] through [3] go out. The result
of computed votes is displayed on Voting Result displays [1]
through [3] on the Central unit.
Note
If voting operation was activated by the Central unit, this operation cannot be terminated by the Chairman
unit. However, if it was activated by the Chairman unit, it can be terminated by the Central unit as well.
Step 4. Clear the Voting Result display.
Press the Voting Start/End button on the Central unit for 1 second or more once again. The display
contents are cleared from the Central unit’s Voting Result display.
(For the Chairman unit)
TALK PRIORITY
Hold down this key
for 1 second or more.
FBS switch
FBS control knob
FBS switch