Linear Phase Without Compromise



When purity is paramount.
A linear phase EQ with unparalleled clarity. For mastering ears, and other discerning engineers.

One Month Introductory Price: $890, $990 List


In A Class By Itself

There are many cheap and cheerful EQs out there. Most sound like…well, you get what you pay for, right? Even in the relatively rarefied world of “linear phase” (LP) equalizers, you have well over a dozen to choose from. Our thEQorange is special, with a clarity and “rightness” you have to hear to believe.

Whether you’re looking for surgically precise repair, colorless correction, or simply baggage–free spectral contouring, thEQorange has no equal. Our proprietary, precision algorithm delivers on the promise of linear phase correction.

Unobtrusive Power

thEQorange’s powerful features hide behind its clean and simple UI. Eye candy is great for newbies, but thEQo ain’t your typical budget filter: thEQorange packs all the advanced features you need into one resizable window that’s easy on the eyes. Not only does the UI “get out of the way” so you can be more productive, we’ve incorporated industry–first features that speed your workflow, neatly packaged to make thEQorange easy and intuitive to use.

Subtle Functionality

We’ve brought pristine fidelity and innovative user interface design to what used to be an unremarkable product category. With four monitoring modes, an ergonomic and uncluttered interface, intelligent monitor auto–gain plus crazy good sound, you’ve got to try thEQorange for yourself.


Better By Design

Pure EQ, with no audible downside. Bring the power and purity of thEQorange to bear for all your equalizing tasks.

thEQorange is the world’s only linear phase EQ software that eliminates temporal smearing to the greatest possible degree.


  • Equal delay at all frequencies regardless of filter settings, perfectly preserving the time relationship of harmonics in the original signal
  • Absence of discernable pre or post–echos; does not disperse signal over time. Transients remain clear and sharp, perceptually true to the original recording.
  • Unique construction results in no perceptable unwanted sonic coloration (processing artifacts well below -100 dBFS) — work with clarity, transparency, and definition
  • Operates at up to 384 kHz sampling rate, suitable for high resolution audio (HRA), DSD or DXD production and post
  • Extended resonant or center frequencies up to 174.14 kHz, for processing in ultrasonic and near ultrasonic for all HRA production and post
  • 12 sections with 5 freely assignable parametric filter types; bell, low shelf, high shelf, low cut, and high cut
  • 5 freely assignable Panorama modes; stereo, mono (sum), L-R (difference), left–only and right–only
  • 4 Contribution modes; positive addition only, negative addition only, EQ contribution only, and “normal” EQ out helps to aurally keep track of your progress
  • Proprietary algorithms result in extremely low noise and vanishingly small nonlinear distortion
  • Adjustable Q for bell and high/low pass filters make musical adjustments easy
  • Adjustable slope for shelving filters improve precision in the pass and stopbands
  • Double the stopband attenuation (ripple) compared to other filter implementations
  • Additional low and high pass filters can be overlapped to achieve steep “brickwall” slopes
  • Special oversampling for analog–like filter characteristics when working with baseband sample rates (44.1 & 48 kHz)
  • No coloration or amplitude bumps even at very low frequencies
  • Inbuilt tone generator makes for quick location of trouble spots
  • SORT function eliminates the need for busy, distracting UI elements
  • TUNE function aligns center frequencies to Western tunings
  • Grid snap toggles between surgical and musical applications, emulating popular hardware resonant frequency choices, including Maselec and Manley
  • AutoGain for effortless A/B comparisons
  • Resizable frequency response display for easy, high precision adjustments
  • The tightest Low Cut in the universe!


  • Exclusive dual view, monochrome/color real time spectrogram with user adjustable temporal wiper lets you choose “when” to transition to low clutter monochrome
  • Ultimate fidelity with all 80 bit, double precision floating point internal calculations
  • Choice of parametric editing via numerical fields or directly on the graphical display
  • Complete setup exchange across multiple instances
  • Automatic latency compensation with all modern DAWs
With all the features and functionality of Algorithmix’s beloved original LP PEQ Orange, the feature–packed thEQorange brings so much more. Use its powerful processing and double precision I/O for:
  • Mastering and remastering tasks on complex, high fidelity mixes
  • Equalizing of instrumental group stereo sub–mixes
  • Clarifying and rescuing dense mixes
  • Addressing resonances and peaky instruments without tonal degradation
  • Removing unwanted ultrasonic content from HRA recordings
  • Identifying resonances with ease when sweeping, due to the low inherent ringing
  • Giving any mix the light touch it deserves
  • Tightening up loose or crowded mixes
What not to use thEQorange for is mixing! thEQorange is a low channel count plug–in, designed for the master buss and mastering. Due to the insane complexity of the algorithm, thEQorange has a high CPU demand. It is not a “light weight”!
thEQorange fits in with all modern workflows:
  • Supports LPCM sample rates up to 384k for DSD and high–end postproduction
  • All standard formats: AU, VST 2 and 3, AAX
  • Compatible with macOS and Windows
  • Low fatigue visual design
  • Resizable user interface for every screen resolution

Filter Facts

Filters or equalizers are hardware or software that provide frequency–dependent gain or loss. The name “equalizer” is a legacy term inherited from when telephones and telegraph were analog tech. High frequency line losses over long distances were compensated for or “equalized” with passive and later active LCR circuits.
In the analog world, there are only IIR or Infinite Impulse Response filters. IIR filters exhibit frequency–dependent group delay or phase shift. This inherent characteristic of IIR filters is part of the coloration or “sound” that each brand imparts. Though a few analog filters intended for mastering applications are designed for minimal coloration, most impart some amount of coloration, especially at extreme settings.
In the digital domain, alongside IIR filters, a filter type not seen in the real world is possible: FIR or Finite Impulse Response filters. FIR filters also exhibit group delay but, unlike IIR filters, with appropriately designed FIR, the delay can be made constant at all frequencies. Thus, it is “pure” or frequency–independent, constant delay.

More Color?

Another coloration present in most all filters is echo, where a lower amplitude delayed version of the signal arrives before or after the signal itself. Wait, before the signal? In the digital world, “linear phase” filters are possible where an echo can appear at the output before the direct signal itself. This is called pre–echo and, to the human ear is both unnatural and unpleasant. Think of “print through” in the analog tape domain…not good.
While LP FIR filters exhibit pre–echo, IIR filters have post–echo where the duplicated audio is hidden at low amplitude or masked “under” the signal itself. In nature, post-echo is common since it’s what we all assume when we think of echo. In the real world, echo always appears after the direct sound. Consider how, in a highly reverberant environment (reverb being a very large number of echoes clustered together in time), speech intelligibility is degraded. This is an extreme example of the perceptual defocusing that post–echo does to a direct signal.

And Now For Something Completely Different

thEQorange is different. By applying advanced theory to the problem of EQ color, we have created a highly complex algorithm that eliminates audible pre–echo and post–echo to the highest degree, and offers constant group delay at all frequencies. No audible echo to blur transient detail, and no temporal stretching or smearing across the audio passband due to differential delaying of frequencies as you find with conventional IIR–based equalizers.
Bottom line: no color. Only the purest frequency–selective gain adjustment you have ever heard. Use other tools for appropriate coloration, but reach for thEQorange when purity is essential.


Take a look at the user manual for details on how thEQo works and how to use it…

thEQorange requires a 3-Series CmStick USB dongle and Wibu Systems’ current software framework. Our CmSticks offer portability, easy disaster recovery and reliabilty for your valuable purchase. Before you say, “Oh no, not another dongle!” consider this; your MAAT dongle investment includes a $50 voucher, which can be applied to your next purchase from our store. Learn more

Reviews & Testimonials

Patrik Schwitter (organ builder, musician, educator, award–winning mastering engineer)

“It just sounds fantastic or, to be more clear, it does not have any sound (i.e. colouration) at all! I'm totally convinced of this orange beauty. :) ”

Tomi Kuusisto, Audio Chef Mastering (EMI Finland, Warner Music)

“The search for the ultimate EQ is finally over. I have to say that you really nailed it with thEQorange!
It is more than an awesome tool for mastering as well as for mixing. I have tried all the mainstream pro plugin EQs out there but thEQorange is something unique; transparent and very musical…The show is not over until the thEQorange sings!”

Олег Ершов (Oleg “Yorshoff” Yershov), engineer & journalist

“This thEQo is simply insane! I’m shocked how good it is…(my) overall impression is just WOW!”

Praise for the original Algorithmix LinearPhase PEQ Orange

thEQorange is a modern restoration of the original Linear Phase PEQ Orange from Algorithmix. Thanks to improvements in technology since the PEQ Orange was released, our new version exceeds the already legendary fidelity of the original. Plus, we’ve added key new tech to the UX (User Experience) to make your time with thEQorange easier and more pleasurable.

Sakis Anastopoulos, Digisound Mastering

“I must tell you that I am absolutely ecstatic with the results that I have been achieving with the linear phase EQs…Both Red and Orange EQs have absolutely replaced every other EQ that I own and have given me the ability and freedom to perform challenging frequency adjustment tasks in every project that I master no matter how challenging or what genre it is…Their ability to resolve with accuracy, clarity and musicality, frequency ranges in complex music passages is astonishing, allowing the mastering engineer to focus on the project and forget the artifacts that are usually associated with this kind of processors.”

Stefan Lindstrom, Swedish Sound Reference AB

“Having the ($6k) hardware Weiss Linear Phase EQ1-MK2 as the reference, I've never expected to hear any other product, especially a software PlugIn, playing in the same league, but the LinearPhase PEQ Orange became to be an indispensable complement tool in our mastering suite.”

Bob Katz, Digital Domain

“…the Algorithmix Red and Orange Linear Phase equalizers are must haves.”

Alan Silverman, Arf! Digital

“…as the final touch-up EQ…the sound is fantastic!”

T-Dogg on our Dr. Christoph’s chops

“The real gurus in the field…Dr. Christoph Musialik, etc. have far surpassed these textbook algorithms…Simply put, genius–level R&D and know–how is priceless.” We concur and know that you will too!

Reviewers! Want to add your voiceover to the mix?

Head to our Contact page and give a shout…We’d love to hear what you think!

Speeds & Feeds

Features, Specifications & Downloads


If you own thEQorange, grab a copy of the current build for macOS or Windows


  • Fully parametric linear phase EQ +
  • Free of temporal and phase distortion
  • Live spectrogram and spectrograph
  • AutoGain for effortless A/B comparisons
  • Variable resonant ƒ tunings for common Western scales
  • Inbuilt tone generator for quick spectral navigation


  • AAX (Pro Tools 10.3.10 and newer), AU, VST2/VST3
  • Sample rates from 44.1 to 384 kHz
  • pluginval_logo  Verified by pluginval, passing with a score of 10 (the highest strictness level)


VST PlugIn Interface Technology by Steinberg Media Technologies GmbH


  • Perpetual: One–Time Buyout
  • Subscription: Annual


  • macOS 10.8 and newer
  • Windows 7 and newer, 32 & 64 bit


Introductory Price: $890, $990 List