## EQ Filters Panel

The EQ Filters panel is displayed by clicking its button at the top of the EQ window.

The panel shows the filters settings for the current measurement. Buttons at the top of the panel allow the filter settings to be sorted, loaded, saved or deleted and the sort direction and key to be specified. The equaliser type can be changed in the Equaliser selector at the right of the EQ window.

Each filter has:

- A check box to select/deselect it
- An identifying number and coloured line showing how the filter will be displayed when showing individual filter responses
- A "Control" setting which should be set to "Automatic" for filters REW is allowed to configure or "Manual" for filters it must leave unaltered.
- A "Type", which for TMREQ and Generic filters can be:
  - PK for a peaking (parametric) filter
  - LP for a 12dB/octave Low Pass filter (Q=0.7071)
  - HP for a 12dB/octave High Pass filter (Q=0.7071)
  - LS for a Low Shelf filter
  - HS for a High Shelf filter
  - NO for a notch filter
  - Modal for a Modal filter
  The Generic and DCX2496 also have shelving filters implemented per the DCX2496
  - LS 6dB for a 6dB/octave Low Shelf filter
  - HS 6dB for a 6dB/octave High Shelf filter
  - LS 12dB for a 12dB/octave Low Shelf filter
  - HS 12dB for a 12dB/octave High Shelf filter
  The Generic equaliser setting also has
  - LPQ, a 12dB/octave Low Pass filter with adjustable Q
  - HPQ, a 12dB/octave High Pass filter with adjustable Q
  For most other equalisers the only types available are PK and Modal, although the labelling for the PK filter varies. The MiniDSP equaliser setting supports all the filter types that Generic supports.
- Centre Frequency/Corner Frequency, Gain and either Q, Bandwidth or Target T60 controls as appropriate for the filter type and selected equaliser. The filter bandwidth in Hz at the half-gain points is shown alongside the Q or Bandwidth control for PK filters.
- Displays of the 60dB decay time in milliseconds for a mode the current filter settings would match and the 60dB decay time of the filter itself, which is the decay which would remain after cancelling the decay of a modal resonance of the indicated modal decay. These correspond to the locations of the zeroes and poles of the filter.

The DSP1124P mode has an additional display showing frequency in the form in which is must be entered on that unit, i.e. as a one-third octave centre and a fine adjustment which ranges from -9 to +10 (63 -5 in the example below).

The Modal filter type is a peaking filter whose bandwidth or Q is adjusted by REW to match a Target T60 time, it is used to accurately counter a modal resonance whose T60 time is known. To match a specific T60 time the filter's bandwidth or Q must be altered as its gain or centre frequency change. REW chooses the bandwidth or Q setting supported by the selected equaliser that most closely matches the target T60.

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