lkjb Plugins has released the QRange free IIR linear phase EQ plugin for Windows and Mac.
The plugin works by block-wise processing an IIR filter forwards and backwards. This results in a symmetric impulse response and thus linear phase operation but also more or less different EQ curves than normal IIR filters.
While the difference is not that big for peak and shelf filters, it is not possible to create a Butterworth (maximum flat before the cutoff) characteristic. Instead Linkwitz-Riley cuts can be used by setting the Q-factor to 0.707 for the 12 and 24 dB/oct filters. The 48 dB/oct cuts are always Linkwitz-Riley.
QRange features
- 12 bands (sortable by frequency).
- Each band can be used as peak, shelf and cut filter.
- Cut filters are available with 12, 24 and 48 dB/oct steepness.
- Stereo/Left/Right/Mid/Side routing per band.
- Global gain for loudness adjustments.
- Resizable user interface.
- Linear phase processing without pre-ringing.
QRange is a free download for Windows and Mac in VST and VST3 plugin formats.
More information: lkjb Plugins