Kirchhoff-EQ is an ultimate 32-band parametric EQ plugin built for all critical professional applications. It has refined sound quality, analogue-matched curves, 15 filter types with continuously variable shape and 32 vintage EQ types modeled from real-world devices. The builtin dynamic processing functions are highly flexible and have ultra-low distorion. All these push Kirchhoff-EQ to a next-generation standard.
Equalizers will never be the same again.
"This is the most advanced and complete hands-down equalizer on the market. Between the extended dyamic control section, all the vintage unit emulated, the sound of it in itself with a new technology, up to 117-bit processing, and all the other features they packed on this one... Hands down. This is the benchmark right now."
Platinum mixing/mastering engineer, producer
"This is the most forward-thinking and exciting EQ I have used in years, and has replaced a number of tools I was using previously. It sounds phenomenal. It has so much control, depth, and power. It's truly a joy to mix with."
Multi-platinum producer, composer, songwriter
"I feel like the EQ plugin market is oversaturated with 2 options. There are great analog emulations and there are great innovative digital equalizers. The Kirchhoff-EQ blends the best of both worlds and I love the intuitive user interface. The dynamic section is great for De-Essing and creative problem solving when I'm mixing and I love that it's so quick and easy to use! I'm truly blown away by this EQ!"
Award-winning songwriter, producer, film composer
"The Kirchhoff-EQ has completely taken the place of multiple EQ's I was using in my daily workflow. Between it's modern/sleek interface, analog matched curves and the option for dynamic/mid side processing, the Kirchhoff-EQ has quickly become my go to EQ - and is now invaluable in my current template."
American musician, producer, composer
"Kirchhoff-EQ is head and shoulders above any other dynamic EQ I've seen. It's quick and familiar to use on the surface, but the depth of features available goes beyond any other EQ. It sounds incredibly smooth and transparent. For me controlling the bell shape is essential for fixing problems transparently and Kirchhoff-EQ makes that extremely quick and flexible. You have full control of downward or upward compression and downward or upward expand with control of attack and release separately for each EQ node. So adding punch or controlling a problem is quick and effective. Being able to independently set the frequency and Q of the side chain for each node is a game changer for those really tricky mastering problems. Everything has been thought through so well. This plugin is a masterpiece."
Multi-award winning jazz mixing and mastering engineer, guitarist
"A reliable EQ is crucial to a producer's toolset. Kirchhoff-EQ's intuitive design and its variable slope filters make it a game-changer. This is now my go-to EQ."
Drum & Bass Producer, YouTuber
"The Kirchhoff EQ has been my default EQ since I discovered it. It handles anything I can throw at it with incredible fidelity. It can be surgical when you need to fix problems invisibly, or it can be big & musical when you want to add color & vibe, all while putting nearly limitless options to equalize a source at your fingertips. And the top end of this EQ is the most analogue I've heard yet."
Grammy nominated audio engineer, producer, musician
"Nothing even comes close!
With its ability to be so musical or surgical if needed, Kirchhoff-EQ is an amazing 32-band parametric EQ plugin made for the most demanding user. with its multiple filter and vintage EQ models this is one analog sounding beast you don't want to be without. INCREDIBLE....
The best of the best has arrived!!!"
Producer, musician, remixer
Through originally developed "Robust Nyquist-matched Transform", Kirchhoff-EQ has made digital-domain frequency response more approximate to its analogue counterparts without high frequency cramping as in regular IIR (infinite impulse response) equalizers. This technique is applied on all filter types in Kirchhoff-EQ.
Frequency response of analogue prototype (blue) and common digital filters (red).
Frequency response of analogue prototype (blue) and Kirchhoff-EQ (red).
64-bit is mandatory and it's not negotiable. The internal processing of Kirchhoff-EQ is always in 64-bit (or 117-bit), regardless of host DAW's current working precision.
All linear filter structures should have the same sound on paper. However in real-world application, round-off errors make every filter structure sound differently: some better in low frequencies, some better in high frequencies.
A technology called "Psychoacoustic Adaptive Filter Topologies" has been deployed in Kirchhoff-EQ. Filter structures change themselves to a "best fitting" state along with corresponding band frequency changes, resulting in optimized sound quality in both low and high frequencies.
Quantization noise of raising 6 dB at 1000 Hz of a very famous EQ.
Quantization noise of raising 6 dB at 1000 Hz of Kirchhoff-EQ.
Since there's already 64-bit, why not go further? Kirchhoff-EQ uses a technique called "Double-Double" to make precision of internal processing reach 117 bits! This is the first equalizer in the world to reach such precision. You can switch between 64-bit and 117-bit at any time. It satisfies the most demanding ears.
* Linear-phase mode always uses 64-bit as it is an FIR(finite impulse response) filter, and does not support 117-bit.
The slope of most filter types can be continuously changed from 0 dB/oct, 6 dB/oct or 12 dB/oct up to 96 dB/oct. Would you like to try a 8.125 dB/oct highpass?
Get vintage and modern at same time! We modeled 9 vintage EQ hardware units as a total of 32 EQ types implemented in Kirchhoff-EQ. Benefit from Robust Nyquist-Matched Transform, every EQ type precisely matches the original hardware and won't cramp near Nyquist frequency. For a further step, unlike the original hardware that only allows to choose between several frequency positions, we modified the DSP model to make adjustable frequency points for all these types! Every type in these models can be used together with regular EQ types or other modeled types, and can be applied with dynamic functions (except lowpass and highpass types). This brings you more freedom and convenient operations.
* No non-linear behaviors were modeled. All vintage filter types only contain ideal linear parts of their physical model.
The phase mode of Kirchhoff-EQ is switchable between zero-latency mode, analogue mode, linear phase mode and mixed phase mode, in order to meet all your phase relationship needs.
* No matter which phase mode currently in, if dynamic functions is turned on for a filter band, it will work on minimum-phase mode (won't affect other bands).
The zero-latency and linear phase modes have a very different sound. Kirchhoff-EQ provides a mixed mode that uses zero-latency when the band frequency point is low, and uses linear phase when it is high. Each band could be changed smoothly between minimum and linear phase mode according to their frequency.
* There is no noticeable crossover between filter types while in mixed phase mode, transition is seamless.
Phase response tends to be linear as frequency increases.
Dynamic functions in Kirchhoff-EQ are not just a bonus, they provide the richest functions you have ever seen. Enabling you to achieve unlimited possibilities of dynamic EQ functions. All filter types (except low/high pass, band pass and notch), even these vintage-modeled ones, can be applied with dynamic functions.
All dynamic EQ have odd- and non-integral harmonics, that’s the laws of physics. By using advanced DSP techniques, Kirchhoff-EQ now "shifts" most energy of odd-harmonics into even-harmonics, creating an ultra-low noise floor and enhanced sound. Now you can use dynamic functions with freedom without worrying about smashing your sounds.
Frequency response of a very famous dynamic EQ working at 1000 Hz. Note the rich odd-time harmonics.
Dynamic function of Kirchhoff-EQ. Note that overall harmonic distortion is decreased whilst new even-time harmonics are generated.
You can now control how dynamics react to the portion of the signal above/below threshold concurrently. In Kirchhoff-EQ, the "Above" stage works as a compressor or upward-expander, and the "Below" stage works as an expander or upward-compressor. For example, you can raise the signal below the threshold AND compress the signal above the threshold to "stabilize" a band.
Let us imagine a simple case: we are playing an audio clip in which sounds around 1khz are 9 dB. You may think "The 1khz range is over powering, We should reduce at 1khz." But we should also consider the overall level. If the whole audio is 30 dB, you would not feel that 1khz is too much, instead you may feel it's not enough. The better criteria to determine whether a band's volume is high or low is its relative portion in overall volume envelope, instead of only its absolute dB value.
Thereby we introduce "Detect/Relative Envelope Detection" in Kirchhoff-EQ. The dynamics are affected by both current frequency band and relative portion to a "Relative" band. The contribution of Relative Envelope Detection to dynamics is also adjustable: when set to 0%, it degrades as a normal dynamic EQ; and when set to 100%, the amount of dynamics is fully calculated from the relative portion.
The “detect” band is set according to the frequency and Q of the band by default, “Relative” is the whole audio envelope by default. But they can be set freely.
The detecting band and relative band have a freely adjustable frequency point and Q value. Or enable “S.C.” mode to use “Detect” or “Relative” with a sidechain signal.
By turning on "Onsets" mix, the envelope detector reacts more specifically to transients inside of the envelope. So you can fine-tune the tone of transients. For better adjustability, you can "mix" envelope detector and onsets detector. For example, you can compress the high frequencies just a little bit whilst compressing the sudden increase of high frequencies more aggressively.
Kirchhoff-EQ allows you to locate a specific frequency peak rapidly by directly grabbing on spectrum.
Kirchhoff-EQ has builtin 2x oversampling that can be freely turned on/off.
Each band can be set as mid/side or left/right processing, so you can pan a band left or right, or adjust Mid/Side, or just left, right, mid and side separately.
4 independent buttons were added to help you to switch left/right/mid/side monitoring more smoothly.
Lookahead is not a feature that can always be found in an EQ plugin. But it's considered necessary for Kirchhoff-EQ's various dynamic functions.
2 ways of stereo width control are implemented in addition to global output gain and pan. You can adjust the ratio between Mid and Side or gain the Side channel individually.
Operational list helps you to check and adjust the basic parameters of every band. Drag an item to arrange the order, or sort them by frequency with 1-click.
Through hand-written assembly code commands, Kirchhoff-EQ achieves ultra low CPU workload. Never fear to use hundreds of instances!
We did our best to reduce clicking noises while performing parameter changes, type switching, bypass on/off and enter/leave solo listening mode.
We are dedicated to smoothness in operating, speed to open/close UI and operation latency. To achieve better rendering efficiency, the GUI of Kirchhoff-EQ is rendered using OpenGL.
The spectrum panel of Kirchhoff-EQ is carefully optimized for visuals and is freely configurable. You can adjust its decibel range, refresh speed, resolution, frequency scaling and brightness. You can even directly specify its center frequency.
How to trigger war on a forum? Ask them if a Q value shall increase/decrease when mouse wheels up. To help speed-up your workflow, Kirchhoff-EQ provides a rich set of options allowing you to cast it to your own handy tool.
Choose your favourite from various GUI themes, or just make a new one only for yourself! Any visual requirements will be satisfied by the highly customizable GUI.
Piano roll display
Customizable knob speed
My favorite filter types
Apple silicon native support
Minimum System Requirements
Plugin Formats Provided
Download & Trial
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After installing Kirchhoff-EQ and logged in with your Plugin Alliance account, you can choose to start a 14-day free trial. A trial license is fully-functional, so you can enjoy all the features of Kirchhoff-EQ. It will be active for 14 days after the first activation. If you are satisfied with the trial, and would like to support us, please come back to Three-Body Tech to get a full license! Learn More.
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Version 1.6.4 (Mar 28, 2023)
- Now AAX plugin is available for native Apple Silicon.
- Allow to customize spectrum refresh rate in Global tab of settings menu.
The available values are between 30FPS and the highest refresh rate of your monitor(s). Changes on this setting would affect Kirchhoff-EQ on all instances in real time.
- Added 7 preset themes.
- Rebuilt OpenGL rendering scheme that improves software stability on integrated graphics cards.
- Now global scale applies to all menus.
- Now the user manual could be opened correctly through PA licensing toobar.
- Fixed unexpected refresh rate changes when making mouse operations on spectrum panel.
Version 1.6.2 (Mar 08, 2023)
- The inactive knobs of the current filter type are grayed out.
- Sharper Q value of monitoring.
- Slightly improved GUI rendering speed.
- Improved stability in native ARM64 Logic Pro.
- Show CPU type in About page to distinguish native/rosetta translated version.
- Fixed the issue that certain parameters does not respond to DAW's automation.
- Fixed occasional high CPU consumption in audio thread.
- Fixed incorrect panel backgrounds.
- Fixed the issue that manually typed output gain and pan values cannot be correctly applied.
- Fixed the issue that copied band cannot be correctly pasted on certain devices.
- Fixed the issue that minus values cannot be typed into certain text boxes.
- Fixed default path for background image customization on Mac.
- Fixed improper popup window in Ableton Live that causes missing plugin.
- Changing Q with mouse dragging now behaves the same with mouse wheel.
- Initial PA Release
List Price: $299
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