Equaliser Menu

The Equaliser menu is used to select the type of equaliser whose responses the wizard is to model. Changing the equaliser type recreates the filter panel, applying the settings appropriate to the selected equaliser. Filters already defined are retained where possible, but parameter values will be adjusted if necessary to comply with the ranges and resolutions of the chosen equaliser. The currently selected equaliser is shown in the filter panel title.

This menu also has entries to select filter optimisation options and reset the filters for the current channel, or for all channels, to None.

TMREQ
Select TMREQ as the Equaliser type, offering the full range of filters and filter settings supported by TMREQ (peaking = parametric, low pass, high pass, low shelf, high shelf and notch). For the Peaking filters the bandwidth in Hz between the half gain points is given by:

Bandwidth = centre frequency/Q

The TMREQ setting allows 8 filters per channel for Left, Right, Centre and Sub and 5 filters per channel for Surr L, Surr R, Surr Back L and Surr Back R. The adjustment ranges are:

ParameterMinimumMaximumResolution
Frequency20200001Hz
Gain-15+60.1dB
Q0.1500.1
BFD Pro DSP1124P
Select DSP1124P as the Equaliser type. In this setting the DSP1124P's parametric filters are supported. The DSP1124P setting allows 12 filters per channel. The adjustment ranges are:

ParameterMinimumMaximumResolution
Frequency2020000see below
Gain-48+161dB
BW/6011201

The frequency control adjusts in the pseudeo-1/60th octave steps DSP1124P supports (20 evenly spaced subdivisions of the ISO one-third octave intervals), with the one-third octave and fine adjustment values DSP1124P uses shown alongside the actual frequency in the Filter Panel.

The "BW/60" control replicates the effect of the DSP1124P's bandwidth setting. This control sets the bandwidth of the filter between the half-gain points with:

Bandwidth (Hz) = centre frequency*(BW/60)*sqrt(2)

For example, at a bandwidth setting of 60/60 a filter centred on 1kHz with a gain of -6dB will have a bandwidth of 1,414Hz between the points where its response crosses -3dB. This bandwidth remains constant as the filter's gain is adjusted (Note that the Behringer DSP1100 software package does NOT correctly reproduce the way the bandwidth control actually operates, its bandwidths are too small by a factor of sqrt(2)).

Defining filter bandwidth in this way is not uncommon (the TMREQ filters use a similar definition). The relationship between Q and BW for the DSP1124P is

Q = 60/[(BW/60)*sqrt(2)]


so the bandwidth range of 1/60 to 120/60 gives a Q range from 42.4 to 0.35.
BFD Pro FBQ2496
Select FBQ2496 as the Equaliser type. In this setting the FBQ2496's parametric filters are supported. The FBQ2496 supports 20 filters per channel. The adjustment ranges are:

ParameterMinimumMaximumResolution
Frequency20200001/60th octave
Gain-36+150.5dB (1dB below -15dB)
Bandwidth1/6010octaves, see below

The frequency control adjusts in approximately 1/60th octave steps (more precisely, 1/200th of a decade).

The bandwidth control adjusts in 1/60 of an octave steps from 1/60 to 5/60 of an octave, then goes through 1/10, 1/9, 1/8, 1/7, 1/6, 1/5, 1/4, 1/3, 1/2, 3/4, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 10 octaves.

The relationship between Q and BW in octaves for the FBQ2496 is

Q = sqrt(2)/BW


so the bandwidth range of 1/60 to 10 octaves gives a Q range from 84.85 to 0.14.
Generic
Select a generic Equaliser, offering a full range of filters and filter settings (peaking = parametric, low pass, high pass, low shelf, high shelf and notch). For the Peaking filters the bandwidth in Hz between the half gain points is given by:

Bandwidth = centre frequency/Q

The Generic setting allows 20 filters per channel. The adjustment ranges are:

ParameterMinimumMaximumResolution
Frequency10220000.1Hz below 1kHz, 1Hz above
Gain-30+150.1dB
Q0.1500.1
SMS-1
Select SMS-1 as the Equaliser type, offering parametric filters only. The filter bandwidth in Hz between the half gain points is given by:

Bandwidth = centre frequency/Q

N.B. The SMS-1 filter shapes have not been verified against an actual unit.

The SMS-1 setting allows 8 filters per channel. The adjustment ranges are:

ParameterMinimumMaximumResolution
Frequency151201Hz
Gain-1360.5dB
Q0.320.00.1
Read Loudspeaker Configuration from Unit Ctrl+R
Read the speaker settings from an AV32R Dual Processor or AV192R over an RS232 serial link via a TAGtronic Programming lead. See Communicating with AV32R DP or AV192R for details of the communications link.
Read Channel Filter Settings from Unit Ctrl+F
Read the filter settings for one or all channels of an AV32R DP or AV192R. Any existing filter settings in the Wizard for the channel(s) read will be overwritten.
Send Channel Filter Settings to Equaliser Ctrl+Shift+F
Send the filter settings for one or all channels of an AV32R DP or AV192R, or for one channel to the left or right bank of a BFD Pro DSP1124P or FBQ2496 (see Communicating with the BFD Pro for details of the communications link).
Any existing filter settings in the equaliser for the channel(s) sent will be overwritten.
Allow Doubled Filters
When matching filter characteristics to resonances the optimiser does not limit filter attenuation, this allows it to correctly determine the required Q for each filter. Once a good match has been achieved, the attenuations are limited to the maximum that the EQ filters allow then the attenuation (but not Q) of each filter is re-optimised accordingly.

If the "Allow Doubled Filters" option is selected the optimiser will allocate an additional filter for peaks that remain above the target level when optimisation has completed. The second filter is chosen according to the following criteria:

As an example, consider a peak at 100Hz that requires a filter with 21dB attenuation to bring the response down to the target, but our filters have a maximum attenuation of 15dB. A further 6dB of attenuation is required. If there is an unused filter then it will be assigned to provide this extra 6dB of attenuation at 100Hz. If not, but there is a filter being used to correct another peak (let's say at 45Hz) that has less than the required 6dB of attenuation, it will be re-assigned to make up the shortfall on the large peak so if the 45Hz filter only required 3dB (for example) attenuation to correct the 45Hz peak, it would be reassigned to apply 6dB attenuation to the 100Hz peak instead.

This process is repeated for each peak that remains above the target level until all available filters have been used or all peaks have been corrected.

Drop Filters if <2dB
If the "Drop Filters if < 2dB" option is selected any Automatic filters which have less than 2dB attenuation at the end of the optimisation process will be freed up (their Type will be set to "None")
Reset Filters for Current Channel Ctrl+Delete
Used to reset all the filters for the current channel to "None"
Reset Filters for All Channels Ctrl+Shift+Delete
Used to reset all the filters for all the channels to "None"

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