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Semi-parametric Equalizer

KH-EQ1 Frontplate
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Manual Download

KH-EQ1 Manual

Supported formats

AAX plugin support VST plugin supprt Audio Unit plugin support

Supported platforms (32/64 bit)



  • Intel Core CPU or Apple SIlicon M1/M2 Processor
  • 1GB of RAM
  • Mac OSX 10.9 or newer (M1/M2 supported)
  • VST, AU or AAX compatible host (64bit)
  • Display resolution of 1280x1024 pixels or more


  • SSE2 compatible processor (Intel Core CPU recommended)
  • 1GB of RAM
  • Windows 7 or newer
  • VST or AAX compatible host
  • Display resolution of 1280x1024 pixels or more


The KH-EQ1 is a semi-parametric 5-band EQ like no other. It features rich-sounding frequency band controls that allow you to add color to each band while encouraging creative sound shaping with its highly musical functionality.

The KH-EQ1 - the second part of the Koen Heldens signature series - is a professional studio EQ with a twist, which features harmonic per-band saturation and our innovative, stepless Mid<->Stereo<->Side router.

Each license includes custom presets created by Koen himself, giving you the professional studio experience you’ve been waiting for.

It is the perfect addition to any producer’s arsenal, and it’s the ideal tool for adding richness and creativity to your productions!

The History of the EQ

The equalizer, or EQ, is one of the most used yet most misunderstood audio processes out there. It is a vital tool that any producer should have in their toolkit. Simply put, it is used to adjust the response of one or more frequencies in an audio signal, which can help shape or make any element of your mix less or more prominent.

The EQ was initially used for telecommunication pur- poses and dates back to acoustic telegraphy. It was later used in radio and broadcast and continued to evolve until it became a staple in every studio.

Daniel N. Flickinger designed the first parametric equalizer in 1971. His invention achieved filtering cir- cuits that were previously impossible, and his patent introduced circuit topology that continues to be rele- vant today. These legendary hardware EQs turned into digital EQ plug-ins with countless customization options and styles as time went on.

While some EQs work more accurately than others, this essential tool allows users to surgically remove or boost any frequency they desire, without compromising the timbre of each element, or by changing it completely. While advanced equalization can take years to perfect, it is a total game-changer when performed correctly - with enough practice, it allows for complete control over any sound. In addition to working on in- dividual elements, it can also be used in mastering when used on the master track of a final mix.

Sound Samples



SSE2 optimized code

DSP operations are pipelined using the SSE2 instruction set. This ensures a high-performance operation despite its very complex computations.

HighDPI/Retina Support

The user interfaces support high pixel density on both Windows and Mac OS systems, giving you the most enjoyable user experience on high DPI displays. Please refer to your DAW manual to learn whether it is HighDPI compatible if you're working on Windows.

About the KOEN HELDENS Signature Series:

The collaboration between Black Rooster Audio and Koen Heldens began with a genuine artist endorsement and has evolved into a great creative partnership. We have maintained a close dialogue over the last 2 years, exchanging technical and artistic knowledge. This dialogue ultimately turned creating original software together into a very inspiring symbiosis. Koen is one of the most knowledgeable and hard-working engineers in the business and has produced music with world-renowned artists, shaping their sound in his very unique style at every opportunity. We are pleased and proud to have Koen use our plugins extensively in every mix and to create his Signature Series.

The series begins with the very unique and versatile KH-COMP1 studio compressor (AAX/VST/AU) and will be followed by three additional units, all designed by Black Rooster Audio in collaboration with Koen Heldens.