The most powerful passive EQ ever! The original hardware Passeq was the first passive EQ to provide three separate frequency ranges for both boost and cut. The Pultec EQ, the famous passive EQ from the 1950’s and 60’s featured just two frequency bands, and had very limited switchable frequencies. SPL’s Passeq has 12 switchable frequencies per band, totaling 36 boost and 36 cut frequencies! Boost and cut frequencies are NOT identical, thus the resultant 72 frequencies per channel offer an enormous choice for the most elaborate EQ curves. The Passeq offers, for the first time, passive filter control possibilities with an unheard of abundance of filter choices.

The fantastic quality of SPL’s Analog Code programming faithfully reproduces the unique sound characteristics of the original hardware Passeq. All the complex interactions between each single filter are faithfully preserved in every detail. One of the unique qualities of passive EQ designs is that the audio signal reacts to the multiple bands as one big filter. Whenever a setting changes, the entire interaction between EQ bands occurs. This provides the unique characteristics and very special sound of these EQs — something that simply does not happen with active EQ designs.

The combination of all this filtering power, mastering grade sonic quality, and advanced M/S processing (a software-exclusive feature!) make the SPL Passeq THE plugin to have for mix busses and mastering.

Download a fully functional 14-day demo today to hear for yourself! (No dongle required!)


  • Includes the standard stereo and a mono version for individual tracks.
  • M/S switch allows for separate processing of M (Mid) and S (Side) signals.
  • Faithful reproduction of the original hardware’s beautiful-sounding interactions between passive filters.
  • 72 filters on three bands per channel.
  • Emulation of input and output transformers.
  • Adds an amazing M/S mode which the hardware doesn´t offer.
  • Four individual “Settings” can be stored for quick A/B comparison, or to automate different settings at different points in the material.
  • Mouse Wheel Control over rotary controls.

Audio Examples

Customer Reviews

  • ★★★★★
    by Pinellimusic
    In my opinion 90% a mastering tool.
    Very smooth and not for all purposes but extremly gentle sounding.
    A great tool in your arsenal. Exellent !
  • ★★★★★
    Classic plugin
    by Constantin
    Even if you do have another passive eq, this one is still unique.
    The workflow itself lends to interesting results that can't be easily replicated with anything else.
    The sound is perfect… Read More
  • ★★★★★
    Yokozuna EQ
    by ITS
    I was looking for a high quality EQ plugin for mastering. I tried maybe 10 of them and this was the best for me. As a musician playing modern heavy rock stuff, I want my music to be heavy yet clear,… Read More
  • ★★★★★
    Inaudible bettermaker
    by Impulsound
    This EQ is the best tool for shelving (boost & cut) and Mid boosts.It sounds so clean and natural in the mids like nothing ive ever had.This Heavyweight mastering sound sculpter has… Read More
  • ★★★★★
    Surprisingly musical and usable
    by Overmann
    Initially this EQ is a bit intimidating. Opening it up for the first time I felt like a padawan staring into the void hoping some jedi master would manifest and give guidance. In these cases the… Read More


Supported Plugin Formats
AAX DSP, AAX Native, AU, AAX AudioSuite, Venue 32-bit, VST2, VST3

Supported Operating Systems
Mac OS X 10.8 through 10.12
Windows 7 through 10
Pro Tools 10.3.10 or higher or any VST/VST3/AU-compatible host running on a supported operating system

Intel CPU only (minimum 2 GHz recommended)

Intel-compatible CPU with SSE2 instruction set (Pentium 4 compatible or higher; minimum 2 GHz recommended)

System Requirements
Display resolution: 1440 × 900px or 1280 × 960px or higher
Memory: 2 GB RAM


With the Installation Manager, you can select, download and install just the Plugin Alliance products and formats you need for your system. During this initial release, we at Plugin Alliance look forward to hearing the feedback of our valued customers, as your input will help shape future versions of this utility.