The Sonoris Linear Phase Equalizer (SLPQ) is a parametric linear phase equalizer. The plugin is suitable for mixing and especially mastering and features 7 bands, including lowpass, highpass, peaking and shelving filters.

The SLPQ can be used to enhance or correct difficult material like vocal or instrumental soloists and groups, orchestral recordings and complex mixes, without introducing any unwanted coloring. The linear phase implementation of the SLPQ ensures a transparent character and just boosts or cuts a frequency range without adding a "sound". It doesn't smear transients or create mud, nor does it alter the imaging and depth information of the original sound. This way it is possible to boost or cut more than with a conventional equalizer without any of these negative side effects.

Every band can be set up to process stereo, L, R or (M)id and (S)ide channels. Processing the mid or side information can be very useful in certain situations. In mastering for example, it allows you to enhance a centered vocal while leaving the other instruments untouched. Or to center a bass without losing the stereo imaging of the rest. Adjustment of is made easy because the SLPQ allows for monitoring the LR or MS channels.

Features:

• 7 band parametric linear phase equalizer.
• backwards/forwards type algorithm.
• 4 quality settings.
• Lowpass and highpass filters up to 48 dB/octave.
• Peaking and shelving filters.
• Stereo, L, R or MS processing and monitoring.
• No pre-warping effects, that is, correct response up to Nyquist.
• HQ mode with upsampling for an even more accurate response.
• Soft Engage technology on all filters to prevent pops and crackles.
• Mousewheel support.
• A/B comparison.
• Large graphical display with draggable handles for maximum control.
• Three zoom levels.
• High resolution level meter.
• Track following.
• Full automation possible.
• SSE and SSE2 optimizations.
• Settings can be saved.
• 64 bit integer math in audio chain, except for the filter code.
• TPDF dither is used to convert the 64 bit signal back to the host resolution.

In the VST version the internal 64 bits signal is dithered to 32 bits. Some hosts, like Reaper and Cubase accept the newer VST 2.4 double floats standard and in those hosts the output is in 64 bits, undithered.