Bosch Appliances 3922 988 43318 manual Sound Management, Equalizer function, Loudspeakers

Digital Congress Network Installation and Operating Manual Chapter 11 - System Set-up and Operation en 11-5

11.5 Sound Management

11.5.1 Equalizer function

To produce optimum speech intelligibility for a particular discussion room or conference hall the CCU includes a built-in system audio equalization facility.This facility automatically sets the overall audio characteristics of the DCN unit loudspeakers. (see fig 11-2 9(3)).

NOTE: Channels 12 (line-output) and channel 13 (delegate/loudspeakers) only will be equalized. See Chapter 13.8 Available Audio Down Link Channels.

REMARKS:

1.The frequency response of a room is dependent on the position of microphone and loud- speaker used, particularly if a microphone is relative close to a loudspeaker. Switching between a microphone-loudspeaker combination and another can result in an entire different frequency response.Therefore, equalization has primarily an advantage if the microphone is in the diffuse field of the loudspeaker, for example if a separate PA sys- tem is used.

2.The equalizer is only active on the delegate loudspeaker channel and the equalized PA output.The equalized PA output is only available on the Audio Media Interface LBB 3508/00, channel 12.

To Equalize the system proceed as follows:

NOTE: Before carrying out the equalization process, it is recommended that the surround- ing area be kept as quiet as possible.

The number of microphones which can be selected for the ‘auto-equalization’ measurement process can be selected by the user. Proceed as follows:

1.Press the equalizing recess switch ‘Start’ located on the front of the CCU to enter the micro- phone selection mode (FIG 11-1).Entry into this mode is indicated by an illuminated busy LED.

2.The chairmans microphone will automatically be selected for the auto equalization procedure, however, the user can select up to 8 microphones to gain better performance. To select addi- tional microphones simply press the ON/OFF button of the relevant microphone. If a chairman unit is not connected to the system, a delegates microphone will be switched on.

3.To activate the ‘auto-equalization’ procedure press the equalizing recess switch ‘Start’ once again. A noise will be heard and the busy LED will begin to flash, indicating automatic equalization is being processed. After the measurements, the filter settings are calculated (this may take a few minutes).

NOTES:

1.To abort the auto equalization procedure press any button on the CCU. Aborting restores the previous equalization settings.

2.Selecting the auto-equalization measurement process is only possible when in the “Single CCU” mode.

3.The equalizer function can be used with or without DCN software running. However, the ‘Auto’ equalizer facility will not function if the DCN software is running.

11.5.2 Loudspeakers

The three rotary loudspeaker controls located on the front panel of the Central Control Unit are used for setting the overall system gain/volume of the DCN’s contribution unit loudspeakers.

•Control (FIG 11-2(6) ) sets the overall volume/gain level of the discussion unit loudspeak- ers in 1.5 dB steps throughout the entire system.

NOTE: When turned fully anti-clockwise the audio signal to all system units, with the exception of the interpreter desk is switched off.

1.Control (FIG 11-2(5)) sets the overall system treble control of the contribution unit loudspeakers.

2.Control (FIG 11-2(5)) sets the overall system bass control of the contribution unit loudspeakers.

How to Set System Volume/gain level

1.Switch on the maximum number of Active-Micro’s (4 plus a chairman unit).

2.Select a delegate unit and speak loudly into it while adjusting the volume/gain control to the point where audio feedback is just audible.

3.From the feedback point adjust the volume/gain control to just below the feedback level.

Bosch Security Systems 04-2003 3922 988 43318 en Sound Management