HoRNet ThirtyOne MK2

ThirtyOne MK2 2.1.0 is available, this update is free for owners of the plugin and includes:

  • Added Apple M1 support

  • Fixed wrong manufacturer name in AAX

  • Fixed sliders with increased value when session was saved with eq amount greater than 50%

  • Fixed LED bars being displayed at full level when no sound was present in some DAWs

Spectrum analyzer and 31 band equalizer with Auto EQ

ThirtyOne MK2 is a plugin that includes a spectrum analyzer and a graphic equalizer, both have the standard 31 one third octave bands.

This pair of tools is very common in every rack of any live mixer as the final tool in the master bus, for this reason we decided to recreate the behaviour and specific time response of a very common Italian analog spectrum analyzer.

The equalizer is also inspired by analog units allowing ThirtyOne to recreate that master chain feeling that you are used to.

We put a great care in recreating the smooth lighting of LEDs driven by a smoothly increasing current flow, each column of twelve LEDs comes after a 20dB/octave filter (like the original hardware unit) and it’s response speed is selectable between 0.25, 1 or 4 seconds allowing you to see both fast peaks and average frequency level.

Each of the LED of the bar can have a value of 1, 2 or 3 dBs (like in the original hardware unit) and we also added 6dB/LED option, when changing the resolution the scale on the left of the LED display updates accordingly.

We also added a maximum peak hold LED for each frequency band that can be enabled or disabled that the original unit did not have.

Right below the spectrum analyzer we have put the 31 sliders that will let you shape the output and fix any particular resonance. Each of the sliders drives a standard 1/3 octave second order filter and can be adjusted from -15 to +15 dB, you can also change the value for each band typing in the box below each slider.

The equalizer has a very special feature called the “Auto EQ”, when enabled the output of the spectrum analyzer is used to tune the gain for each of the EQ band allowing the equalizer to automatic set itself so that the maximum harmonic balance is achieved.

ThirtyOne MK2 provides three different “Auto EQ”  algorithms: Average, Median and Lucky, the first two are based on some mathematical models while the third one is a lucky mistake and we decided to keep it because it sounded good 😀

“Auto EQ” is linked to the frequency analyzer output so changing the analysis speed affects the algorithm, using the 0.25s changes the equalization very fast and allows you to track also the fast frequency spikes, while using the 4s setting works more on the average frequency content.

To tune the “Auto EQ” output you can use what we call a “compensation curve” which is an offset that it’s applied to every level computed by the “Auto EQ”, so if you think that the resulting eq curve it’s too extreme in some band you can correct it using the “custom” setting of the compensation curve. If you find a compensation curve that you like you can export it and then load it in other projects using the “load” and “save” buttons.

The resulting EQ curve can be decreased or increased using the “EQ Amount” knob that scales every gain computed by the “Auto EQ” algorithm by a fixed value and allows you to increase or reduce the level of each band while maintaining the same ratio between them.

Demo limitation

The demo is fully functional except for the fact that every now and then it will silence out, you cannot save parameter values with your session and the plugin will not respond to automation coming from the host.


  • 31, one third octave, spectrum analyzer bands.
  • Spectrum analyzer carefully crafted to give you the feeling of analog hardware units.
  • three different integration times for the analyzer.
  • four scale ranges for the analyzer.
  • peak hold display.
  • display both the L+R (mid) component or the L-R(side) component of the audio spectrum.
  • 31, one third octave, equalizer.
  • Each band of the equalizer can be bypassed.
  • Each band of the equalizer can be put in solo mode.
  • Each band of the equalizer can be disabled for the AutoEQ.
  • Each band gain adjustable from -15 to +15 dBs.
  • “Auto EQ” automatically balances frequency content.
  • Three different algorithms for AutoEQ.
  • AutoEQ can work both in continuous or fixed mode.
  • Each of the two modules can be disabled to save CPU.
  • AutoEQ amount knob to scale the effect impact
  • Custom compensation EQ profile for the AutoEQ algorithm
  • Compensation curve can be saved and loaded
  • Preset save and load
  • Bypass button for the equalizer.
  • GUI is scalable and hardware accelerated.
  • macOS (>=10.11, Metal required) and Windows (Windows 7 and later, OpenGL 2.1 required) support.
  • Apple Silicon native support (except for AAX)
  • 64-bit plugin for Mac and Windows.
  • Audio Units VST2.4, VST3 and AAX format.

Copy protection

The HoRNet ThirtyOne MK2 has no copy protection, we don’t believe in copy protection, they are always cracked and they are annoying for the users, we all know you are not going to give away the plugin on the internet…

So simply download the plugin and enjoy your recordings!

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16 thoughts on “HoRNet ThirtyOne MK2

Giulio says:

Il migliore di quelli che ho provato Saverio, i miei complimenti, utilissimo in fase di mastering.

Ron says:

I love this plugin to clean up my mixes, CLEAN! But for aesthetics I think removing the glow from around the db circles will make the UI look cleaner or tone the glow down some. But nevertheless, I'm very happy with the purchase. 5 stars for me if the glow wasn't there…

Marcel says:

become my go to clean cloudy tracks!! amazing for home recording

macop says:

AutoEQ removes sound clouding. Creates a reference point for adjustment.

vittorio vandelli says:

I tried the demo for 30 seconds and that was enough to buy it, compared to more famous plugins it doesn't look out of place at all

Tom Goodson says:

Ciao ai miei amici di Hornet! Guys, this plug-in continues to be my go-to eq when dealing with especially difficult frequencies. I'm the guy who recommended the mute/solo feature on the individual bands, which you graciously added, and I own numerous Hornet plug-ins.

Do you know what would make 31 even more super? If you added presets similar to the Abletunes EQ WISE+ equalizer. I just found this EQ this morning and the presets blew my mind. It doesn't make EQing foolproof, but it would sure make it easier. How about it?

Jeffriezal Jaafar says:

I get the demo after i stumble upon discussion in a forum, to be honest, it is not perfect but i never desire auto/AI eq because it always far from the ideal result im looking for. But on this one, it just set the result to the direction im heading to, and the rest of it is left for me to tweak to my taste, purchased confirm!

Ne Si says:


FREQ ISO says:

this plug in solves a lot of issues for me. "seeing" is believing . easy to use and to the point. its my go to "fixer" eq . 5 stars. thx!

Fello Toro says:

my macOS is 10.9.5 and using protools.
cant make it work man. can someone help me. it sucks cause i really love the company but this is not the first time it happens.
please, i really want to use the plugin.

thank you very much.

Joshua Love says:

Still unable to get it to work in ableton. It shows up in AU but not in VSTs. Anyone know how to resolve the issue? I sent support some messages a month ago and still haven't gotten a functional response yet. I'm very excited to use this plugin and as far as I know others got it to work in ableton. Not sure what I'm doing wrong.

Joshua Love says:

I am still trying to get it to work in Ableton live 9.7.7 64-bit with no luck so far. It shows up but doesn't load.

jonas imstre says:

Great,Great,Ggreat! Amo Lei come mastera Eq ^) Grande lavoro e oggi io ho comprto! Domani comincio lavorare! Sono felice!!! Grazie

Tom Goodson says:

And now, one of my rare product recommendations. I’ve been using Hornet ThirtyOne EQ for a couple of years now and they have recently upgraded it to a MK2 version. ThirtyOne is my “go to” EQ for isolating problem frequencies; however, until now I never used it much for every day EQing because the interface was just too inconvenient. I have been bugging the developer for like 2 years to add a solo button on each frequency band where each band can be listened to individually without zeroing out all of the other bands. Well, they finally did it and now ThirtyOne is perfect. Well… perfect for me, that is.

imstre says:


Robert Ryda says:

I was waiting for an update for a very long time! And here it is, Im happy to have this release and to be one of the first ones to get an upgrade from the original version!

The old version worked but had inconvenient/minor glitches (maybe its just the AAX version), and some of the features were not there and here it goes!

Saverio – you are the man! Thank you! I just purchased it and will install it now!
5 stars before using it you might say? True, but I already own the MK1 version and this one has the features I've waited for and I know it will work far better this time!


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