Gated Ambient Compensator Component

VIDEO TUTORIAL: Video tutorial available online for Gated Ambient Compensator.

The purpose of the Gated Ambient Compensator is to control the gain of a Program, for example, announcements, in a situation where the ambient noise varies.

The ambient noise is measured, and as it increases, the applied gain to the announcements increases at a set Ratio, so that when the announcement is made it is loud enough to overcome the ambient noise. When the announcement level exceeds the Threshold Level, the Ambient Detector becomes inactive so that the announcement is not measured along with the ambient noise. When the announcement level falls below the Threshold Level, the Ambient Detector again becomes active.

When the ambient noise is low, and an announcement is made, depending on the input level of the announcement, and the gain settings in the Compensator, attenuation may be applied to the announcement so that it is not too loud.

Controls

The controls listed below are divided into sections to match the Control Panel sections.

Once you establish the initial settings for a component, you can save those settings, along with all the other component's settings, in a Snapshot.

General

Control

Function

Default/Range

In Gain

(dB)

Adjusts the microphone input level.

Default = 0

Range = -20 to 20

Detector

(dB)

Displays the ambient level, including any program material present.

Range -60 to 20

Response Panel

Graphically displays the operation of the Continuous Ambient Compensator.

The X axis represents the recovered ambient signal RMS level.

The Y axis represents the dB gain that is applied to the program material.

N/A

Bypass

When engaged, the Continuous Ambient Compensator is bypassed.

Off/On

Gain

(dB)

Displays the gain applied to the program material.

Range -60 to 20

Out Gain

(dB)

Adjusts the Program output level.

Default = 0

Range = -20 to 20

Mic Filter

NOTE:  Depending on the Type of filter you select, some of the controls listed below may not be available.

Control

Function

Default/Range

Bypass

When engaged, the Mic Filter is bypassed, the ambient noise is not filtered except by the Audio Bandwidth setting in the Properties.

Off/On

Type

Selects the type of filter to use.

Low-Pass

High-Pass

Band-Pass

Band-Stop

Parametric

Low-Shelf

High-Shelf

Bandwidth

(Octave)

Sets the width of the frequency band to be filtered. Available only with the Band-Pass, Band-Stop, and Parametric filters.

Default = 1

Range = 0.01 to 3.00

Frequency

(Hz)

Sets the frequency of the filter. For filters that have a bandwidth setting, this is the center frequency of the bandwidth.

The upper limit for this control is either 1.25 kHz, 2.5 kHz, or 5.0 kHz depending on the Audio Bandwidth Property.

Default = 100

Range = 10 to 5000

Gain

(dB)

Sets the gain for the Parametric, High-Shelf, and Low-Shelf filters.

Default = 0

Range = 0 to 20

Detector

Control

Function

Default/Range

Program Threshold

(dB)

Sets the threshold, of the Program input, above which the Ambient Detector is not active. When the program level falls below this setting, the Ambient Detector becomes active

Default = -60

Range = -60 to 20

Sense Delay

(seconds or milliseconds)

Sets a delay in the time it takes the Ambient Detector to go from inactive to Active. This is to compensate for momentary pauses in the Program input.

Default = 1.0

Range = 0 to 10.0

Sensing

LED indicating if the Ambient Detector is active or not.

Off/On

Gain Calculation

Control

Function

Default/Range

Ambient Threshold

(dB)

The crossing point of the ambient level and the Minimum Gain. At this point, as the ambient level rises, the gain applied to the Program moves from the Minimum Gain towards the Maximum Gain. The point at which the ambient level is high enough to have an impact on the Program gain.

Default = -30

Range = -60 to 20

Ratio

( n:1)

The ratio between the Minimum Gain and the Maximum Gain as measured from the Ambient Threshold Level. The closer the Ratio is to 2, the lower the ambient level needs to be for the Maximum Gain to be used when the Program input passes the Program Threshold.

For example: If the Ambient Threshold is -30 dB, Minimum Gain is -10 dB, Maximum Gain is 10 dB, and the Ratio is 2.0, when the ambient level reaches -20 dB, Maximum Gain is applied when the Program Threshold is reached.

Same example except the Ratio is 0.5. When the ambient level reaches 10 dB the Maximum Gain is applied when the Program Threshold is reached.

Default = 1

Range = 0.5 to 2.0

Minimum Gain

(dB)

The minimum amount of gain you want to apply to the Program output when the ambient noise is at it's lowest point. Usually a negative amount, or attenuation - shown in red on the Gain meter. Gain is added to the Program input level up to this setting. If the Minimum Gain is -15 dB, and the Program input level is 5 dB, the Program Output is -10 dB

5 + (-15) = -10

Default = -20

Range = -20 to 0

Maximum Gain

(dB)

The maximum amount of gain you want to apply to the Program output when the ambient noise is at it's highest point. Gain is added to the Program input level up to this setting. If the Maximum Gain is set to 10 dB, and the Program input level is 5 dB, the Program Output is 15 dB.

Default = 10

Range = 0 to 20

Time Constants

The time constant is the time it takes to cover 63% of the control change. For Attack, the start gain is 1.0 (unity) and the end gain is 0. After 10 seconds, the value is at 1-0.63 = 0.37, which corresponds to -8.7 dB. For Release, the start gain is 0 and the end gain is 1.0 (unity). After 10 seconds, the value is at 0.63 which corresponds to -4 dB. Depth is ignored in this calculation, it simply limits the filtered gain to a minimum.

Control

Function

Default/Range

Attack Time

(seconds)

Sets the time it takes for the output amplitude to rise to 63% of the specified Ratio of the input amplitude once the Ambient Threshold Level is exceeded.

Default = 1

Range = 1 to 10

Release Time

(seconds)

Sets the time it takes for the output to fall to 63% of the level set by the Minimum Gain control after the Ambient Detector level drops below the Ambient Threshold Level.

Default = 1

Range = 1 to 10

Properties

Property

Function

Choices

Microphone Filter

Determines if the Mic Filter is active and available in the Control Panel.

Yes / No

Control Pins

The available Control Pins depend on settings in Properties.

Pin Name

Value

String

Position

Pins Available

Ambient Detector Level

-100 to 20

-100 dB to 20 dB

0.000 to 1.00

Output

Ambient Sense Delay Time

0.00 to 10

0 ms to 10 s

0.000 to 1.00

Input / Output

Ambient Threshold Level

-60 to 20

-60 dB to 20 dB

0.000 to 1.00

Input / Output

Applied Gain

0 to 20

0 dB to 20 dB

0.000 to 1.00

Output

Attack Time

1 to 10

1 s to 10 s

0.000 to 1.00

Input / Output

Bypass

0

1

active

bypass

0

1

Input / Output

Input Gain

-20 to 20

-20 dB to 20 dB

0.000 to 1.00

Input / Output

Maximum Program Gain

0 to 20

0 dB to 20 dB

0.000 to 1.00

Input / Output

Microphone Filter Bandwidth

.010 to 3.00

.010 to 3.00

0.000 to 1.00

Input / Output

Microphone Filter Bypass

0

1

active

bypass

0

1

Input / Output

Microphone Filter Frequency

10 to 5000

10 Hz to 5 kHz

0.000 to 1.00

Input / Output

Microphone Filter Gain

-100 to 20

-100 dB to 20 dB

0.000 to 1.00

Input / Output

Microphone Filter Type

1.00

2.00

3.00

4.00

5.00

6.00

7.00

Low-Pass

High-Pass

Band-Pass

Band-stop

Parametric

Low-Shelf

High-Shelf

0

.167

.333

.500

.667

.833

1.00

Input / Output

Minimum Program Gain

-20 to 0

-20 dB to 0 dB

0.000 to 1.00

Input /Output

Output Gain

-20 to 20

-20 dB to 20 dB

0.000 to 1.00

Input / Output

Program Threshold Level

-60 to 20

-60 dB to 20 dB

0.000 to 1.00

Input / Output

Ratio

0.500 to 2.00

.500 to 2.0

0.000 to 1.00

Input / Output

Release Time

1 to 10

1 s to 10 s

0.000 to 1.00

Input / Output

Sensing

0

1

false

true

0

1

Output

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