Author: Debanka

The Rate Control audio object controls the rate at which control signals can pass through the object. This is implemented by blocking the controls for a duration that is specified as a tuning parameter.

Rate control Properties

Below table describes the audio object properties and functionalities.

Properties	Description
Number of controls	Enter the number of control inputs. The number of control outputs is always 2. The index of the pin (which receives the first control signal) is sent out on the left output pin first and then the control signal itself is sent on the right output pin. Range: 1 to 255 Data type: xFloat32 Default: 1
Display Name	Display name of the Rate control audio object in signal flow design. It can be changed based on the intended usage of the object.

Mode

There are currently no modes available for the Rate control audio object.

Additional parameters

There are no additional parameters available for the Rate control audio object.

Tuning Parameters

There are blocking times associated with each control input pin which could be changed as a tuning parameter.

Parameter	Description	Data Type	Range	Default	Unit
BlockingTime	Time for which any new control signal is blocked	xFloat32	0 – 60	0	seconds

Control Interface

There are no control parameters available for the Rate control audio object.

Native Panel

Rate control audio object does not support a native panel.

The FaderMatrix audio object is used to calculate the weighted output based on a combination of input audio where the weighting factors are provided as control input.

Use Case: The FaderMatrix takes in a configurable number of input, output and control channels. Each output of this object is a weighted sum of all the input channels where weighting factors can be tuned from control inputs.

Fader Matrix Properties

Below table describes about the FaderMatrix audio object properties and functionality.

Properties	Description
# of Audio In	Number of input channels. Range: 1 to 64 Default: 2
# of Audio Out	Number of output channels. Range: 1 to 64 Default: 2
# of Elements	Number of Control Inputs. Range: 0 to 64 Default: 0
Display Name	Display the name of the FaderMatrix audio object in signal flow design. It can be changed based on the intended usage of the object.

Mode

There are no modes available for FaderMatrix audio object.

Additional Parameters

The FaderMatrix audio object can be configured with the following additional parameter:

Parameters	Description
Gain Type	The audio object has an additional configuration ‘Gain Type’ to specify the weighting factors scale. 0 – Linear [default]: Weights are configurable in a linear scale in the range of -100 to 100. 1 – Logarithmic: Weights are configurable in a logarithmic scale in the range between -128 to 40 dB.

Tuning Parameters

The FaderMatrix audio object has one control index tuning parameter for each input channel that will used to compute the output of each channel. Thus there will be NumInputs * NumOutputs control indices (tuning parameters).

When the control index is set to zero, none of the control inputs will be used and this particular input will not be considered for computation of that particular output

Parameter	Description	Range	Unit
Control Index	Index of the control input for selecting weight factor for each input and output combination.	0 to NumElements	None

Control Interface

The FaderMatrix control is triggered whenever a control message is addressed to the audio object. The FaderMatrix audio object has configurable control input pins for weighting factors.

Parameter	Description	Gain Type	Data Type	Range	Default	Unit
Weighting Factor	Weight factor for each input and output combination.	Linear	Float	-100 to 100	0	None
		Logarithmic	Float	-128 to 40	-128	dB

Native Panel

The FaderMatrix AO does not support native panel.

The purpose of the VolumeLite audio object is to control the volume in the audio pipeline. The VolumeLite audio object is lightweight and different from the “Volume Mute” AO. The object can alter the output volume by either attenuating or amplifying the audio.
This audio object supports ramping and each channel has its own set of – state variables as well as ramping parameters.

Use Case: The object can be used to control the volume of an audio channel.

VolumeLite Properties

Below table describes the VolumeLite audio object properties and functionality.

Properties	Description
# of Channels	In SFD, the number of channels is specified, and the number of input channels is equal to the number of output channels. Range: 1 to 128 Default: 1
Block Control	The object supports Block Control when the object is configured with more than one channel. It has one block control input which controls the output volume of which size is equal to the number of channels configured for the audio object. Block Control is enabled by default and cannot be disabled.

Mode

There are no mode available for VolumeLite audio objects.

Additional Parameters

Parameter	Description
Boot Level	It specifies the required volume level at boot time when configured. It is applicable for all the channels. Range: -128 dB to +20 dB. Default: 0 dB

Tuning Parameters

The following are the tuning parameters that can be configured from GTT.

Parameters	Description	Range	Default	Data Type
Ramp Up Time	Ramp up time in ms per channel.	0 to 1000 ms	5 ms	Float
Ramp Down Time	Ramp downtime in ms per channel.	0 to 1000 ms	5 ms	Float
Ramp Shape	The shape of the volume will change accordingly once it is triggered and applied across all channels.	Linear Exponential	Linear	ULong
Volume	Volume to be applied per input channel	-128 to 20 dB	0 dB	Float

All the channels can be tuned with one command as all are in the same subblock compared to the Volume Mute object.

Control Interface

The Volume control is triggered whenever a control message is addressed to the audio object. Block Control is deployed only when the object has more than one channel. It has one block control input, the size of which is equal to the number of channels configured for the audio object.

Parameters	Description	Range	Unit
Volume	Volume to be applied per input channel	-128 to 20 dB	dB

Native Panel

The native panel for the VolumeLite audio object is under development.

The Control Mixer object supports native panel. The native panel window consists of rows and column. The number of row and column depends on “number of control inputs and outputs” configured. 

In Non Weight Mode, table cells can have only two values 0 or 1.

In Weight Mode, table cells can have values from 0 to 1.

Control Mixer supports copy-pasting values from and into Excel sheets.

You can store the specific configuration and recalled via Store Preset option available on the panel. Configure the tuning parameters and select the free preset slot numbers, enter the name of the slot, and click Store preset. This saves and stores the current tuning data to the selected slot.

If you do not enter a name of the slot, then it will take the default named “New Preset”.

You can switch between presets slots and apply their values by simply clicking on them. Additionally, after clicking to override the preset, you can modify the tuning values in that tab or change the preset name.

To reset the selected preset or all the preset values.

• Click Reset Selected to clear the preset that is currently selected.
• Click Reset All to clear every preset in the corresponding native panel.

The Control Router audio object supports native panel. The native panel window is a dynamic native panel. Panel get adapted in size based on the Router AO configuration. 

By default, all outputs are disconnected.

Every output has an input that can be configured. More than one output can be assigned to a single input signal.
It is possible that some input signals are not assigned to any output.

Additionally, this panel enables to store presets for specific configuration.

Name of preset is configurable in separate window after click Store button:

Fast Conv filter native panel allows you to configure the Mode of each enabled filter and to load coefficients as well. In order to see the graphs, you need to import coefficients. Use ‘Import’ or ‘Import All’ option  to import coefficients.
To open the native panel, double-click on the Fast Conv filter audio object in the signal flow designer.

Amplitude/Phase: When the coefficients are given and “Amplitude/Phase” option is selected, the graph display the value.

Coefficients:  When the coefficients are given and the “Coefficients” option is selected, the graph displays the values as per below figure. You can change the graph style using the “Chart Style” option.

Line chart style: when “Chart Style” selected as Line, the Coefficients graph.
Dot chart style: when “Chart Style” selected as Dot, the Coefficients graph.

Group Delay: When the coefficients are given and “Group Delay” option is selected, the graph display the values.

Curves Legend: This option allows you to show the details of which graph tab (Amplitude/Phase, Coefficients, Group Delay) is selected.

On the selection of Amplitude/Phase graph tab Curves Legend will show below information.
On the selection of Coefficients graph tab and Chart Styles ‘Dots’, Curves Legend will show below information.
On the selection of Coefficients graph tab and Chart Styles ‘Line’, Curves Legend will show information.
On the selection of Group Delay graph tab, Curves Legend will show information.

Additional Functionalities

• Flat: This is used to make the graph flat by making coefficients to 0.
• Import: This function is used to import the coefficients for a single active filter. Click the “Import” button, then enter the file path and click Ok.
  All coefficients for the selected filter will be imported, as shown in the graph. If the number of coefficients does not match the number of taps as shown in the screenshot below, a warning pop up will appear. Click ‘Yes’ to import available coefficients or click ‘No’ to cancel the import.
• Export: This option is used to export coefficients for selected active filter into csv file.
  
• Export All: This option is used to export all active filters in one go. Click the “Export All” button, then enter the path and file name, then click Ok. A xml file will be created which will have coefficients for each active filter. 
• Import All: This option is used to import all coefficients in one go. Click the “Import All” button, then enter the XML file path and click Ok. All the given coefficients will be imported and can be seen in the graph. 
  
• Read:  This is used to read from the target to display in the panel.
• Send: This is used to send the values changed in panel to target.

LUT object supports native panel.  Double-click on the LUT object to open the native panel. Set the values accordingly.

Redo/Undo: The redo and undo functions enable you to rollback or repeat the modifications made to panel cell values, units, minimums, and maximums.

Customizable Axis Label: The customizable axis label allow to change the axis label name. Double-click on axis label will show textbox where you can change axis label name.

This guide explores a comprehensive library of audio algorithms from Harman. It includes over 90 algorithms that can be used to create new, flexible audio processing units (Compound Audio Objects). These CAOs can be fine-tuned, protected with passwords, and shared as easily as any individual audio object.

For all Audio Objects, inside their respective tuneXTP() methods, the received tuning data is NOT checked for valid range limits.
– If the Audio Object (AO) is tuned from GTT, the GTT ensures that the tuning parameters remain within the range prescribed by the toolbox methods.
– If the Audio Object (AO) is tuned using methods other than GTT, like SVE or xTP tuning, it is the responsibility of those entities to ensure that the tuning parameter values remain within the valid range as mentioned in the Audio Object Description User Guide.

The audio objects are categorized into the following groups in the GTT.

• Interface Objects
• Basic Objects
• Control Objects
• Routing Objects
• Source Objects
• Mixer Objects
• Dynamic Object
• Filter Objects
• Core Objects

The ParameterBiquad panel can be used to apply Biquad filters to the signal. It is accessed through the Normal biquad object and Parameter biquad audio object, each offers different modes. When using parameter one or parameter one control set mode, channel selection is not required since the identical biquad parameters are applied to all channels within the device.

The frequency axis scale based on the minimum value of either the maximum value of Frequency StateVariable or (Selected Sample Rate / 2 )* 0.999.

Channel List

On the top left of the EqPanel, there is a list from which you can choose a channel for the current core. The current channel is marked with a green square and its details are displayed in the header of the channel list.

EQ Chart

This chart represents the influence of all Biquads on the frequency and phase response. The left axis shows the amplitude in dB, and the right axis shows the phase in degrees. The number of Biquads are defined with the Signal Flow Designer. The Biquads get dynamically managed inside the GTT. Most of the Biquads are represented by appropriate markers.

Markers

Markers are movable. Moving them allows you to amend the current Biquad parameters. Each marker corresponds to one or two Biquad parameters. For example, the equalizer shown below has three markers.

Biquad Settings

On the Biquad settings window, you can perform the following operations.

Enabling Bypass

• Click on the Bypass button to enable or disable Bypass.
• In bypassed state, the button is red colored and green colored when biquad is in non-bypassed state.

Biquad is in bypassed state by default.

Change the Frequency, Gain, and Quality

• Frequency: It is used to set the center frequency of each filter.
• Gain: It is used to set the center frequency gain of each band of the filter. Not all filter types offer a variable gain.
• Quality: It is used to set the width of each band pass or notch type band of the filter. Not all filter types offer a variable quality factor.

• • Using the increment and decrement buttons you can change the value.
    Or
  • Select the tuner and use mouse scroll to adjust the value

Change Biquad type

The Biquad Filter Menu shows a list of all Biquads types that are set up in the amplifier for the current channel. You can change the Biquad type or remove the Biquad by setting it to Bypass (at the top of the list).

Biquad Chart Type

• Amplitude phase: It is used to turn on and off appropriate charts.
• Phase Unwrapped: It displays absolute values.

• • If the phase is wrapped, the display is limited to ± 180 °.
  • If the phase exceeds 180 ° or -180 ° it is continued on the other side of the vertical scale.

• Used Biquads: This informs you about the available Biquads. The first number is the number of Biquads that have not been bypassed. The second number is the number of available Biquads.
• Sample rate: It shows the sample rate at which the filters are operated.

Biquad Curve Legend

Click on Curve Legend to display all the associated legends. By default, all the curve legends are enabled on the graph. Uncheck the curve to hide it from the graph.

High Order Filters

The biquad object does not support natively high order filters. To work with high order filters, biquad panel can merge two low order filters into one high order filter automatically. Below table describes the rules of combining the filters.

First biquad Type	Second biquad Type	Comparison	Result
HighPass2	HighPass1	B1Freq = B2Freq and B1Q = 1	HighButterworth3
HighPass2	HighPass1	1.03*B1Freq = 0.93*B2Freq and B1Q = 0.69	HighBessel3
HighPass2	HighPass2	B1Freq = B2Freq and B1Q = 1.31 and B2Q = 0.54	HighButterworth4
HighPass2	HighPass2	B1Freq = B2Freq and B1Q = 0.71 and B2Q = 0.71	HighLinkwitzRiley4
HighPass2	HighPass2	1.04*B1Freq = 0.93*B2Freq and B1Q = 0.81 and B2Q = 0.52	HighBessel4
LowPass2	LowPass1	B1Freq = B2Freq and B1Q = 1	LowButterworth3
LowPass2	LowPass1	B1Freq/1.03 = B2Freq/0.93 and B1Q = 0.69	LowBessel3
LowPass2	LowPass2	B1Freq = B2Freq and B1Q = 1.31 and B2Q = 0.54	LowButterworth4
LowPass2	LowPass2	B1Freq = B2Freq and B1Q = 0.71 and B2Q = 0.71	LowLinkwitzRiley4
LowPass2	LowPass2	B1Freq/1.04 = B2Freq/0.93 and B1Q = 0.81 and B2Q = 0.52	LowBessel4

• B1Freq – first biquad frequency
• B2Freq – second biquad frequency
• B1Q – first biquad quality
• B2Q – second biquad quality

Export & Import

Biquad parameters can be exported by clicking the export button as csv in the below format.

The exported file can be imported back to the panel using the import button.

Coefficient biquad native panel is launched for the Coefficient biquad audio object. The panel has two modes.

• Coefficient
• Parameter

The frequency axis scale based on the minimum value of either the maximum value of Frequency StateVariable or (Selected Sample Rate / 2 )* 0.999.

Coefficient Mode

Panel contains channel drop-down and option to import and export coefficients. The panel has a chart that has only total amplitude and total phase graphs.

The “Send” button sends the biquad coefficients to the device. The biquads configured will show up with 5 coefficients each numbered 1 to n.

The coefficients will have default values 1,0,0,0,0.

Coefficients cannot be edited. It can be filled only by importing coefficients from a .csv file. The format of the file is shown below.

The current implementation will import coefficients to the biquads that are configured and leave the biquads that is not listed in the import file untouched. Please make sure you add default values to the ones that do not have coefficients.

Presets at the bottom to save different coefficient values are supported like any other native panels.

Parameter mode

In this mode, you can set parameters using filters, just like in the EQ Panel. Parameters for all channels can be exported and imported.

The “Calculate” button calculates all parameters to coefficients but does not send them to the device. It switches to Coefficient mode so that they can be checked and sent with the “Send” button.

It is not possible to calculate coefficients to parameters, so it is possible that the coefficients will be different than the parameters. That is, the parameter mode may not reflect the state of the device/coefficients. It is possible after loading parameters sets, reading data from device or importing coefficients.