The Sonoris Linear Phase Equalizer (SLPQ) is a parametric linear phase equalizer in the SAWStudio native format. 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. The linear phase algorithm of the SLPQ is based on a technique called ?backward-forward filtering?, until now only implemented in some expensive high end equalizers. The main advantage of this technique is that IIR filters can be used instead of FIR filters, the latter is commonly found in linear phase implementations. IIR filters are known for their more analog kind of filtering and are also more efficient than FIR filters. The filters used in the SLPQ are actually the same as in the Sonoris Equalizer! The plugin has a large graphical display that shows exactly what you get. The Sonoris Linear Phase Equalizer has a HQ switch that enables an upsampling mode. In this mode, the SLPQ has an even more accurate response, especially at the higher frequencies.