The most powerful passive EQ ever.
Made by Brainworx in cooperation with SPL.

The original hardware Passeq was the first passive EQ to provide three separate frequency ranges for boosting and cutting. 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 plugin 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 network. 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 make the SPL Passeq THE plugin to have for mix busses and mastering. Its 10Hz Sub Band and the 16kHz Top band sound truly mesmerizing.


  • Includes 2 Plugins: standard stereo and a mono version for individual tracks
  • M/S processing on board
  • Faithful reproduction of the original hardware’s beautiful-sounding interactions between passive filters.
  • 72 filters on six bands per channel.
  • Emulation of input and output transformers

Audio Examples

Customer Reviews

  • PassEQ

    by maddison
    LOVE this sound of this plugin. Wish I could read the numbers on the GUI though!
  • SPL Passeq

    by Peter Indenkämpen
    I was looking for something like this for a while now: a neat plugin for subtile adjustments. But I got so much more! This one is great. I've got the feeling that everything gets brighter and some… Read More
  • SPL PassEq

    by macman
    First impressions, I am not going to bore you with terms like punch and other well used terminology. The bottom end added a rich and tasty chocolate sauce to bourbon vanilla ice. The top end required… Read More
  • PassEq

    by MrB
    For this tool I can say only few things, absolutely excellent for any situation, from mix to mastering stage.I wish all the best to P.A Team,and Happy New Year
  • Passeq review

    by Bamboom
    Smooth eq, very transparent and you can dial the frequencies you need to boost or cut easily. The bottom end is so awesome, just brings out a roundness to the track or mix. Great tool, use for mixing… Read More


Supported Plugin Formats
AAX DSP, AAX Native, AU, AAX AudioSuite, VST2, VST3

Supported Operating Systems
MacOS 10.9 through 10.14
Windows 7 through 10

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.