Sound Settings

Sound Settings

• The front information display control head control module (J523) is installed only in vehicles with MMI 2nd Generation. On vehicles with MMI 3rd Generation, this was replaced by the information electronics control module 1 (J794), which functions as the front information display control head control module.

• On the Basic and Standard amplifiers the digital sound system control module (J525) is integrated with the radio (R).

General Information and Components

The multimedia control head (E380), the front information display control head control module, and the digital sound system control module are used for the sound settings.

Fader

The fader adjusts the sound between the front and rear speakers. The multimedia control head adjusts the value. The value is evaluated by the front information display control head control module, which is connected with the multimedia control head through a serial interface and sent via the MOST-bus to the digital sound system control module. This sets the ratio between the front and rear channels using the value and then emits either a stronger or a weaker signal. The ratio can be adjusted so that audio output comes only from the front speakers or only from the rear speakers. The fader function is normally available only on vehicles with front and rear speakers. If an adjustment is not possible, then it is due to an incorrect fader setting.

Balance

This feature balances the sound between the right and left sides of the vehicle. The multimedia control head adjusts the value. The value is evaluated by the front information display control head control module, which is connected with the multimedia control head through a serial interface and sent via the MOST-bus to the digital sound system control module. This sets the ration between the right and left channels using the value and then emits either a stronger or a weaker signal. The balance can be adjusted so that sound does not come out of one side at all.

Frequency Correction

Passenger compartments in vehicles do not have optimum acoustics. Passenger compartments with material or leather trim have difference acoustics. The acoustics are stored in a data set so that the speaker signals can be adapted to the vehicle. The digital signal processor will digitally correct the frequency to produce the best possible acoustics inside the passenger compartment. Tone frequencies, which are insulated from the passenger compartment, are amplified.

Surround Level

The digital signal processor will delay the signals in the speaker so as to create a three dimensional sound. When the surround level is set to minimum, then the audio signal is emitted undelayed and in pure stereo. The more the surround level is increased, the stronger the surround effect. This effect is attained in that the output signals from the rear speakers are delayed opposite to the signals from the front speakers. The signal amplification (volume), of the individual speaker signals remains unchanged. This way the surround level has no influence on the fader setting.

The multimedia control head adjusts the surround level. The value is evaluated by the front information display control head control module, which is connected with the multimedia control head through a serial interface and sent via the MOST-bus to the digital sound system control module. The value in the digital sound system control module adapts the channel.

Navigation Audio

The digital signal processor is able to mix the message and the audio source (for example, CD) while the navigation system is giving an instruction. More than 2 values can be selected using the multimedia system control head to set the loudness of the language for the audio source. The values are evaluated by the front information display control head control module, which is connected with the multimedia control head through a serial interface and sent via the MOST-bus to the digital sound system control module. If, for example, the navigation system is going to give a direction, the digital sound system control module will automatically adjust the volume. The audio signal will be lowered so that the direction can be understood. The adjusted volume will be emitted through the different channels while the other sound settings will be maintained. Fader, balance and other settings are not affected.