Airwindows

Slew4

TL;DW: Slew4 is tape compression without the tape, for brightness control.

Slew4.zip (542k) standalone(AU, VST2)
Slew4 in Airwindows Consolidated (a separate project) under ‘Brightness’ (CLAP, AU, VST3, LV2)

You’ve heard of a cat without a grin and a grin without a cat, and you’ve heard of plenty of tape plugins without tape compression… but how about the compression without the tape?

Slew4 does just one thing, but it does it incredibly well. It finds digital edges and glare and high frequency tizz, and it wipes out JUST that, to whatever extent you like, using new filtering ideas I don’t think have been used before in this way. The Airwindows Slew plugins have long been a secret weapon for just this purpose, but this takes it completely beyond anything I had.

That’s why this is the technology in TapeHack2, and what got included in ConsoleH and ConsoleX2 as hasty updates soon after they came out, and why it’s a significant part of ToTape9 which I’m doing everything I can to finish up. Now it’s there for you to use and control, without any sort of saturation stage or any other sort of tape modeling, in its purest possible form.

One thing that means is, if your sound isn’t bright enough, there is no chance you’ll ever hear it do anything. With the right kind of vocal track this is a de-esser all by itself. For other vocal tracks, even ones with pronounced esses, you’ll find it does absolutely nothing. It ONLY cares about the very highest highs, and excises them so neatly you’d never know they were there.

Slew4 runs two samples of lookahead to do what it does, and makes its filter by stacking up averaging filters with even numbers of samples in them. These produce stopbands with big cancellation nodes in them, but when you stack them up, each new cancellation node targets a bump (between nodes) from the previous one… so it becomes a very steep roll-off with good filtering past the cutoff, and no pre-ripple meaning it has incredible time domain performance for something that steep. The strangeness of the stop-band response is probably why this wouldn’t have found use before, but it turns out to sound fantastic, especially when it’s just reining in the highest highs without touching anything else.

If you liked TapeHack2, you already like this! Enjoy playing with it as a dedicated brightness tamer :)

Airwindows Consolidated Download
Most recent VCV Rack Module
download 64 Bit Windows VSTs.zip
download Signed M1/Intel Mac AUs.dmg
download Signed M1/Intel Mac VSTs.dmg
download LinuxVSTs.zip
download LinuxARMVSTs.zip for the Pi
download Retro 32 Bit Windows VSTs.zip
download Retro PPC/32/64 Mac AUs.zip
download Retro PPC/32/64 Mac VSTs.zip
Mediafire Backup of all downloads
All this is free and open source under the MIT license, brought to you by my Patreon.

Date March 8, 2026
Author Chris
Comments 2 Comments

BezEQ2

TL;DW: BezEQ2 is a unique, subtle three-band shelving EQ.

BezEQ2.zip (506k) standalone(AU, VST2)
BezEQ2 in Airwindows Consolidated (a separate project) under ‘Filter’ (CLAP, AU, VST3, LV2)

Turns out there’s a reason BezEQ sounded so weird! Bugs. Both in the sense of ‘what’s that doing there’ and ‘hey, this could be very different and it just might work’. So now there’s two BezEQs, the first one is still a strange strange beast, and this one is…

…fugitive?

It’s hard to explain how different this became. It’s still a three-band EQ made by crossing over filters in such a way that re-adding them produces perfect fidelity: that works great even on steep filters like SmoothEQ. It even works if you do funny things like heavy phase shifting in the filter… or if, like in this filter, you’re delaying bands to more accurately cancel out bass frequencies. (This filter incurs a little bit of latency, depending on how the crossovers are set, because of these delays.)

Far from the first BezEQ, this BezEQ2 has a special knack for hiding what it’s doing. It can boost highs, boost bass, and the result is weirdly like no change was made. There’s a quirk where if you cut the middle all the way to zero, the highs will also cut out (a side-effect of how the delays are set up). It’s still not exactly normal.

And then, perhaps a factor of how the bands are summed together, if you go to cut highs or lows, BezEQ does the opposite. It gives you a midrangey sound with a lot of punch and character. This, even though it’s doing the opposite of last week’s FatEQ, and isn’t distorting anything. Something about how the Bezier curves handle transient impact, combined with the phase-altering delay lines, makes the plugin a heck of a secret weapon for heightening midrange drama and impact. Or, you can just set it up as first a mids cut, and then even more of a bass cut, and get a really articulate, natural-sounding energy lift that sounds remarkably unhyped for all the hype it sneaks into a track.

I have a feeling this is gonna be a real ‘sleeper’ plugin. It seems to do anything I ask while sounding like nothing was done. Those who are trying to mix by adding color upon color to their sounds, probably won’t get this at all. But those of a simpler, rawer approach might really be pleasantly surprised. Even startled, in the best possible way.

Airwindows Consolidated Download
Most recent VCV Rack Module
download 64 Bit Windows VSTs.zip
download Signed M1/Intel Mac AUs.dmg
download Signed M1/Intel Mac VSTs.dmg
download LinuxVSTs.zip
download LinuxARMVSTs.zip for the Pi
download Retro 32 Bit Windows VSTs.zip
download Retro PPC/32/64 Mac AUs.zip
download Retro PPC/32/64 Mac VSTs.zip
Mediafire Backup of all downloads
All this is free and open source under the MIT license, brought to you by my Patreon.

Date March 1, 2026
Author Chris
Comments 4 Comments

FatEQ

TL;DW: FatEQ balances bands only with density.

FatEQ in Airwindows Consolidated under ‘Filter’ (CLAP, AU, VST3, LV2)
FatEQ.zip (534k) standalone(AU, VST2)

This experiment has always worked, but I’m not sure people understand why they gravitate to it.

Usually when we do an EQ, we take frequency bands and turn them up and down, uniformly. A normal sound will get louder, a loud one louder still. Or, a sound will get quieter, a quieter sound quieter still.

FatEQ uses the functions I use in Density (including an upgrade to negative Density settings) so that, if you’re boosting, a normal sound will get louder, but a loud one will softclip. If you’re cutting, to a certain extent a normal sound will get quieter but a quieter sound will get LOTS quieter. It uses variations on sin() functions to mess with the transfer functions in these ways that are tied to what you’re doing with the slider.

It’s easy to hear what this does by just turning all the bands up. It’s super-dense, overdriven, a multiband distortion, and you can totally do that.

But as you do it, notice: doesn’t everything also seem closer? That’s the heart of FatEQ, more than its ability to just crank and overdrive stuff.

The way these controls work, if you’re making small adjustments you’re not just making loudness changes. The softclips and antisaturations have the effect of moving sounds toward you, or farther away. Cutting any control to zero will totally remove that band, but smaller adjustments lean heavily into the ‘we’re attenuating the quiet detail/we’re overdriving the loudest stuff’. As a result, you can EQ spatially: if you have unpleasant low-mids muddying things up, your adjustment can not only turn them down but make them step physically back. You can dial it in based on the sound coming into focus at a desired distance. Top-end too forward? Small adjustments to sit it at the position of the rest of the sound. Lows receding? Well, bring them right out until they’re part of the instrument the way you wanted.

It’s a little unusual, but every time I’ve done anything like this, including just making EQ-like things that had saturation in ’em, people have loved the result. So, FatEQ just directly delivers what you might like in an EQ. See if it works out for you! Read More

Date February 22, 2026
Author Chris
Comments 3 Comments

ZAcidLowpass

TL;DW: ZAcidLowpass is like if an e6400 went insane and grew shark teeth.

ZAcidLowpass in Airwindows Consolidated under ‘XYZ Filters’ (CLAP, AU, VST3, LV2)
ZAcidLowpass.zip (522k) standalone(AU, VST2)

Okay, next week we can get normal :)

This algorithm is less than a week old. It’s what happened when I tried to extend my Quadratic Bezier Curve audio processing to Cubic Bezier Curve audio processing. And I’m not sure it’s time to give up on that, but in the meantime, the experiment failed spectacularly.

So, generating curves can follow various rules. The quadratic bezier curves are already breaking audio rules, as what they do has nothing to do with frequencies, or harmonics, or any audio concepts. They’re drawing a continuous curve directed by the sample values and it turned out this is possible, but it doesn’t have audio significance. It’s quite good at handling control voltages, like in a compressor! But it’s still kind of arbitrary, constructing a curve from the starting position of a previous sample.

The cubic bezier curves proved much less manageable.

In theory, you could get interesting results out of them since you get two independent control points, but it turned out weirder: there’s this tendency to draw the curves, indeed make them be interesting curves with striking contours, but then jump around in the reconstruction. It’d not-randomly space out the curves with tiny straight lines like a sawtooth wave gone mad. Very pretty but never joining up the waves into something smooth and connected. The idea was to see where the extra control point took the reconstruction, but at least for now it took the reconstruction to crazy-town.

And produced a horrible hybrid of a steep resonant ringy filter, and a ring modulator, and I don’t know what else. I never heard anything like that, and so there was only one thing to do.

Put the Z filters output stage on it so you could distort it wildly, and let people have it. What else?

The cutoff is roughly what you’d expect, a frequency control. Over gives you highpassing, under gives you lowpassing, both gives you the original sound (this is a sort of crossover! somehow!). Meltdown does a specific thing: rather than feeding the filter with an averaged, darker input, you can feed it with the raw audio input and get aliasing and chaos fed into the points and control voltages, and this sounds wilder and dirtier. If you’re using Over to produce highpassing, Meltdown is reversed, and setting it to 0 gives you the crazy overtones and harsh noises. Drive is like the other Z filters, and so is Output, and the distortion stage is the same as in the Z filters, so if you’re using those and would like a contrast that’s still tonally similar, this is the plugin for you.

They can’t all be ToTape9 :) if this suits you, have fun!

Airwindows Consolidated Download
Most recent VCV Rack Module
download 64 Bit Windows VSTs.zip
download Signed M1/Intel Mac AUs.dmg
download Signed M1/Intel Mac VSTs.dmg
download LinuxVSTs.zip
download LinuxARMVSTs.zip for the Pi
download Retro 32 Bit Windows VSTs.zip
download Retro PPC/32/64 Mac AUs.zip
download Retro PPC/32/64 Mac VSTs.zip
Mediafire Backup of all downloads
All this is free and open source under the MIT license, brought to you by my Patreon.

Date February 15, 2026
Author Chris
Comments 3 Comments

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