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Airwindows is one guy: me! I am an audio hacker and computer programmer from way back. I seek only to continue my life up here in Vermont, inventing things and putting them onto the internet, sometimes for free and sometimes for pay. My hope is that people richer than me (i.e. most people) don't rob me. My other hope is for another cup of Aeropress. One out of two ain't bad!


TL;DW: Optimized Airwindows echo with a twist!


Here’s a nice little addition to the Purest line of Airwindows plugins (minimal, stripped down, extremely deep and rich tone in simple and uncompromised ways).

PurestEcho gives you four echoes, sample-averaged to deliver extremely precise timing, each with its own tap. That means you can use it as a delay line and set up discrete echoes which then stop completely: no feedback, only a series of trailing echoes which then get out of the way and don’t mud up your mix. Or you can use it for just a single slapback (use the last, for the longest delay time). Or, you can set up odd effects like increasing volume slapbacks, or use of only certain taps.

Or, you can get a tone that’s part of the 90s: turn all the delay taps on full and then set the delay time really short. You’ll find there’s a tightly controlled pipe-like honk that emphasizes a musical tone… sort of a Dalek-like robot-like thing… and you can play this using the slider. Note: this slider is NOT smoothed, because it’s smashing the buffer anyway, but more importantly if you’re programming in a bassline using this effect you’d need it to abruptly switch frequencies. So think of it as something you’d play via control automation, not so much through live entry on the slider.

Between that and the ability to throw a big rich echo that fakes ‘feedback’ but then gets right out of the way, I think PurestEcho will find its way into peoples’ workflows. I hope you like it :)

My work’s paid for via Patreon, which is going nicely: if I reach the $700 mark, which could happen even this month, in upcoming months I’ll not only release the next ‘greatest hit’ (ToTape is up next!), but I’ll also pick one from the bottom of the list that’s less (in total sales) than what the Patreon is at. By definition that immediately makes plugins like StarChild, Golem, PurestWarm, and PocketVerbs possible, plus some favorites of my own like ElectroHat. (there’s another Patreon goal where I’m still releasing stuff from the bottom of the list, but it’s YOU guys picking it :) at that point, Aura and OneCornerClip will be within reach…)

I’ll get to work on the latest ToTape, and if all goes well I will have another little nifty plug next week while I work on ToTape. Thank you for being there for me! :)

BussColors 4

TL;DW: The Airwindows console emulations, now working up to 192K correctly.


I’m very pleased to bring you the latest version of BussColors :)

This plugin’s a pretty huge deal: it’s been around since before console emulations were a thing, and I’ve been steadily working on it year after year. There’s not been much to do: my original algorithms, once I moved past the earliest incarnation as the ‘Character’ plugins, were so solid that it left little to do. BussColors has sold $22,445 of plugins over the years, as Audio Units alone, in spite of the fact that it has always been a 44.1K plug (due to being based on a convolution model).

The story there is, a guy at NoiseVault always wanted someone to make a plugin which used his sets of hardware convolution kernels, which he’d done at all different levels. Sort of the Nebula thing (Giancarlo has been a great help when I was getting the VST thing going, check out Nebula)

I’m not that. I’m Chris from Airwindows… so I set out to make my own version of this sort of thing, with hardcoded algorithms generated on-the-fly, as raw and close to the metal as I could get it. And I got some pretty respectable CPU efficiency with all of the tone quality I wanted, limited to 44.1K.


Try it. BussColors4 is the newest version of BussColors, and it works at any sample rate and gets you the same sound. Better, in fact: I like what it does a lot better at 96K and 192K. It also doesn’t greatly expand processing and CPU hit at higher sample rates. I think this one’s a real highlight of the Airwindows arsenal. It would definitely be worth your $50, like its predecessors (well, I always did give existing BussColors users free updates for life, I mean for new buyers). Feel free to shoot it out against the most expensive and/or CPU-hungry options and I think it will clobber all comers.

And since it’s a Patreon supported plugin, it is AU and Mac/PC VST, and it is free. Now, if you LIKE me bringing the industry tools like this to use, you might find it in your best interest to throw me a buck a month using the Patreon so I continue to make and upgrade these plugins. BussColors didn’t used to be ‘all sample rates’, until I worked out how to do it properly, and now it is. I think if you look at the stuff I’ve done, and the stuff I’m preparing to do, you’ll see the point of supporting the Patreon.

It’s a long video. Feel free to just download and start using the plugin, and I hope you like it. :)

Iron Oxide Classic

TL;DW: Old school tape emulation, extra pure and free of grunge.

Iron Oxide Classic

As promised, here is the 2017-ized version of the pure, sweet, original Iron Oxide. No more grit or tape flutter or noise!

It’s funny how this works. If you’re a commercial developer, and you release a plugin that’s real popular, one thing that happens is people begin asking for more. More features, more variations, this and that and the other. The flutter in Iron Oxide 5 came about that way: it migrated over from ToTape (which is also coming to free VST).

Every new thing added is something lost. But since I’m no longer doing strictly commercial development (it’s steadily all becoming free, backed by my Patreon which allows all this to happen) I can do things like confuse the ‘market’ and release both the feature-full Iron Oxide 5, and the stripped-down Iron Oxide Classic. This one is just like the original: input trim, ips control, and output trim. Better yet, it has the pure unsullied tone of the very first Iron Oxide, only brought up to date so it noise shapes to the 32 bit buss etc.

Even if you liked the grunge factor of the very adjustable Iron Oxide 5 (more controls may be added but bear in mind I have a commitment to release plugins like BussColors, not just keep revising Iron Oxide!) you might want to check this out. And if later versions of Iron Oxide wandered away from what works for you, for instance if you’re making electronic music and needed much cleaner handling of synthetic tones… this is your lucky day!

Hope you like Iron Oxide Classic. It is, truly, one of the Airwindows classics, now for free VST and brought up to date. :)


TL;DW: An unusual edge-maker.


This plugin is a weird little science experiment. I’ve got Iron Oxide Classic coming, but I still have to make a video for it and get it ready (and do the other offshoot TapeDust) and this one was ready to go, so here it is :)

Bite puts on a sort of midrange edge. At high sample rates it’ll be more of a trebly edge. It’s no specific frequency, so much as it’s just a harshening factor: you can also use it inversely, to take out midrange edge. It runs a couple samples of latency: on VST that works as a couple samples of delay. Again: an experiment, a science project.

I’ve got some changes (new things you can get) in my Patreon. There’s a new, easier goal to reach: if we get to $700 a month, I will begin releasing a plugin a month from the bottom part of the list: the ones that are on the tail end, scheduled for a loooonnnnggg time from now. That’s in addition to ‘in order of popularity’, which I’m still doing. The ones from the bottom are my pick: the only thing is, I will pick only ones whose lifetime sales are less than what my Patreon is at. As it gets higher, it opens up more possibilities, but I already have some I could do. For instance, StarChild, ElectroHat, or PurestWarm.

As before, if I get to $800 I will begin open sourcing one plugin from what I’ve already released (my pick).

If I get to $900, I will make it YOUR pick which ‘tail end of the list’ plugin we get. It’ll be some sort of vote of patrons or something. Same deal: pick one that has less lifetime sales than my Patreon is at. By $900 that includes Aura (a killer!) and Single Ended Triode, and OneCornerClip. There are a few real prizes in there.

And as before, if I get to $1000 on the Patreon, I’ll put out two free plugins from the top of the list, which will make reaching any particular plugin go twice as fast. And so on… I’m just adding new stuff between the other goals so that we can see more of the fancy plugins come out quicker. It seems to help teach people what I’m about :)

Next, Iron Oxide Classic, as soon as I make the video!

Iron Oxide 5

TL;DW: The old school, heavily colored Airwindows tape emulation.

(there is a build of the initial version available: IronOxideInitial5 is the first version, before I added the noise level control. I’m providing it in case people need it for special circumstances, but you should NOT have it and the full Iron Oxide 5 installed at the same time, because they share plugin identities and you’ll confuse your computer)

The legacy of this plugin goes way back. Many years ago, I was coding some of my first AU plugins, and some friends of mine were having bad experiences with a company that sold the big tape emulation plugin of the day. Outraged, I charged into the fray: I would code a replacement for them, one that did the same things and sounded better and sold for $60 (later $50). And that was Iron Oxide. It had one ‘ips’ control, a Drive, and an output level.

Then, I expanded on that with Iron Oxide 2. That one split the ‘ips’ top and bottom cutoffs, so you could vary the ‘bandpassy’ quality it had. It used the same unusual algorithm, but made it more flexible. It also incorporated an unusual sort of anti-aliasing in the form of a ‘tape noise’ factor that blurred slew.

Iron Oxide 3 added flutter. At this point, we stepped away from strictly zero latency: instead, the plugin declares zero latency but produces a fuzzy smear across one or two samples, the range the flutter covers. That persists with Iron Oxide 4 and 5, and is how the current free VST Iron Oxide works.

Iron Oxide 4 added something else that (come to find out) is also present in the Delta Labs Effectron: inv/dry/wet control. That persists with Iron Oxide 5. The way you use it is, set up an Iron Oxide tone that accentuates a frequency range (like mids). Drive it, or leave it clean… but begin setting the control to inv (the inverted position). You’ll subtract it from dry, causing a dip rather than a boost, but if you’re saturating the ‘tape’ then the dip will leave dynamic energy in the area being cancelled: it will cut out fat, leaving punch. Overdrive the ‘tape’ section harder (and turn down ‘inv’) to get more punch out, or leave it clean and use it just to cancel out the area. It’s an unusual effect, but it works.

Iron Oxide 5 is all of this, plus lessons from the ‘Purest’ line of plugins (mostly still in line to be released later) to produce the same thing as Iron Oxide 4, but even more pure and resonant and intense. None of these are really ‘mix buss’ plugins (though I’m not the boss of you): they’re far too intensely colored and distorted. They’re more about ‘make that snare really bark’ and so on. Though of course, since I’m not the boss of you, I can’t prevent you from trying to use it on the full mix. All I can do is say that ToTape is coming, and that’s the MODERN tape emulation. This is the old school, rowdy, obvious tape emulation, full of grunge and bark :)

And it is free, because it’s supported by Patreon. We’ve passed the threshold where I’m releasing the formerly-Kagi ‘greatest hits’ plugins, and as long as I stay over $600 a month, that continues. If I top $800 I begin open sourcing the plugins too, and if I top $1000 a month I’ll be releasing two of these greatest hits a month, in addition to other plugins and related plugins and YouTube videos showing you how to do things.

A splendid time is guaranteed for all, and I hope you enjoy Iron Oxide 5. Stay tuned for ‘TapeDust’, the ‘analog tape grain’ aspect of Iron Oxide isolated and put under your control so you can have it separate from the complete plugin (i.e. no overdrive or distortion), and I am open to also doing an ‘Iron Oxide Classic’ which goes right back to Version 1 and acts like the much simpler distorted bandpassy emulation where it all began. Ask and you shall receive :)

Swappable Mega Dark Hat

Here’s another Airwindows studio post that serves two purposes. One, I’m showing you an alternate mega-dark and loud hi-hat sound (like the acoustic version of a low-fi sampled dark hat) you can make with a $50 Wuhan cymbal and some tin-snips. But it was also an experiment to see if the Xiaomi Yi camera compresses its microphone. It does not! So this is what THAT sounds like, and also this serves as a YouTube reference. The drum parts are completely smashed to hell, and YouTube is getting the raw cam footage directly. So, this will show you what YouTube is currently doing with heavily distorted audio. If they pad this, then they’re in ‘normalization mode’ and will also turn down over-loud masters. If they leave it, then they’ll accept at least brief ultra-loud content. Refer back to this video if YouTube experiments with how they transcode stuff, to see if it changes!

This is supported by Patreon :)


TL:DW; A different bright EQ from any other.


Digital EQ is a series of trade-offs. You can have a general effect with a simple calculation, or a more complicated effect with more calculation, or you can just bury the audio in calculation and get something very precise which unfortunately is just a huge pile of mathematics. And digital EQ shows this: it’s typically some digital-audio textbook calculations, maybe with distortion or a convolution impulse on top of it. When it does extreme things, like sharp or resonant filters, it bogs down in the details and loses texture, and it’s a rare developer (like Andy Simper with his nifty ‘The Drop’) who can do something interesting with ’em.

Enter Airwindows.

These are something different. They’re ‘air band’ boosts (less effective as cuts, or you can over-cut to create odd cancellation effects) based on an entirely different principle, basically interacting with the sample rate directly as if it was a ‘gearbox’. There’s a feedback parameter that serves to increase the resonance of the filter, making it ring and produce still another tonality.

The thing is, you don’t get to adjust them. I can’t give you 14K out of the 15K tap, and that number only relates to if you’re at 44.1K sampling rate: if you’re at 48K it’s actually boosting 16.3K. This is the technology that turned into ‘Energy’ (a forthcoming Kagi-class plugin on the ‘patreon release list’, and it can’t be adjusted: it’s a little black box and we’re only doing a dry/wet with each tap (the Filter Q affects all taps).

But what it CAN do is give you a ridiculously powerful boost at 10K, 15K or 22K, and let you sharpen it. It’s doing that with far less processing than you’d usually have to do, to get the result, and it’s doing it as a simple add so it retains the tone of the audio. And one more thing: if you do a super-sharp resonance, with normal EQ that’s linear phase you have to produce extensive pre-ring to get that filter curve. Air doesn’t do that. All its ring takes place after the initial transient attack, so Air is unusually good at sculpting the attacks of trebly sounds… for instance, EDM high percussion and hihats and sampled cymbals… and doesn’t blur where they attack, at all.

That makes Air a VERY good secret weapon for tightening up the percussiveness of hats and snares on EDM. Whatever genre you’re in, you can dial-an-attack and there will be no blurring from the EQ. Your options might be limited to a few bands, but on the other hand you can make crazy blends (they’re parallel) and get unique tonalities all with ultra-sharp attacks, even if you’re maxing out the Filter Q to make things sound very, very unnatural.

Sometimes that might be exactly what’s needed :)

Oh, but please don’t actually treat it like a secret weapon. Treat your SETTINGS like a secret weapon, and tell people if you’re finding Air useful. That’s because I survive through a Patreon that has replaced the previous form of Airwindows, and it’s done so well that now we’re starting to release the greatest hits of Airwindows! If all goes well, Iron Oxide 5 is coming out next week, and you can have the latest version of the second most popular plugin Airwindows ever made, with $27,844 in sales over its lifetime as a $50 plugin. And it will be FREE. And at the next funding goal, I begin the process of also making them open source. So please don’t treat Airwindows plugins as a secret weapon. Treat it as a Patreon, and the more the merrier: it lets me do more interesting things if I can afford to do them :)


TL:DW; Distortion and demolition of air molecules, modeled.


Here’s something rather special. What if you could distort like air molecules distort?

I studied recordings of competitive tractor pulls, of Space Shuttle launches, various recordings that represented the way air can be mangled and break apart. The result is Loud… a step into a much louder world. It’s a distortion that can be slammed to unthinkable ‘heart of a supernova’ dB levels, but can also be subtly introduced to give the sonic coloration of a big LOUD noise in open air. Makes for a very interesting ‘glue’ at zero boost!

Here’s how it’s done: rather than apply a consistent transfer function like a normal distortion, Loud knows whether you’re compressing the air, or letting it rebound. And if it’s snapping back, it can do it with the speed of lightning, but if it’s compressing, the air can be squished to practically solid, increasing heat. This extreme nonlinearity is why Loud sounds the way it does. It can sit on a whole mix to give it scope and authority, or it can be pushed harder on individual tracks like guitars and drums to amp up the ferocity.

Remember, if you’ve got it totally fuzzing out, you are probably already beyond any sound level achievable by human means. The completely fried sound of cranked-up Loud is not meant to seem like acoustic phenomena as we know it. It turns up that loud because I grew up reading Douglas Adams’ “Hitchhiker’s Guide to the Galaxy”, and because in no other way can you accurately emulate a Disaster Area concert. :)

If you like me inventing things like this, support my Patreon. It’s over the funding goal of $600, meaning that I will start to release the Kagi for-pay plugins, one a month, starting with Iron Oxide 5 (the newest version, never seen before!). But there are other goals to reach, too: at $800 I will begin open sourcing these plugins under the MIT license, and at $1000 I will release two of the Kagi plugins a month—twice as fast! Sky’s basically the limit. And for today, as a token of good will, I bring you the loudest noise in the universe :)

Speed-King-Izing Axis Longboards

I’m getting together a huge (18) pile of new plugins to make, including the mighty Iron Oxide 4, and also dealing with a YouTube issue where someone’s tried to copyright strike white noise generated in a ToTape4 video, and trying to fix my porch. But I’ve got time to share some drum pedal experiments with you!

This is how to make Axis longboards ‘feel’ more like Ludwig Speed King pedals, but without the squeaks and vintageness. It’s all about the geometry of the linkages, and works great: you should see right away how this works, and how it’s done. If you have questions, ask! :)

Things are looking good for May to be my first month of releasing the premium, Kagi-era plugins. As long as the Patreon is still over $600 when May begins, we’re good to go, and probably it will stay at least at that level from now on (not like I’m going to stop being Chris from Airwindows or anything ;) )

The next stages of the Patreon are reaching $800 (where I begin open-sourcing what’s been put out already, plus my templates for making all the plugins) and $1000 (where I start putting out the premium plugins TWICE as fast, two a month, on top of everything else I’m releasing). It’s exciting to see where this is going!

Hope the glimpse into lever-hacking (for that’s how you Speed-King-Ize an Axis pedal) was fun! Next one is an alternate hi-hat sound, an unusually good dark LOUD hat for roughly $43 plus a pair of tin-snips. Then the flood of new plugins resumes :)

High Impact

TL:DW; Grit and punch without fatness.


Sometimes it’s all in the name.

High Impact has been one of the Airwindows secret weapons for a long time. It’s a pretty basic idea: know how Density distorts and makes audio huge and fat, and Drive distorts and doesn’t make stuff as fat? High Impact answers the question, ‘what if you could distort and not make things fatter AT ALL’.

This is not EQ I’m talking about, though it can come off like EQ depending on what you feed into it. High Impact combines a distortion and anti-distortion circuit to reshape the transfer function of the audio, as follows: crank it up, and quiet subtle samples aren’t turned up much. Then medium samples are turned up a LOT, and then the loudest samples are distorted and hit a wall past which they can’t go. The result is an obvious distort which doesn’t bloat things. It’s a ‘dial-a-rasp’, or ‘dial-a-slam’ for percussive noises, and though the concept is two different kinds of overdrive combined, it’s an Airwindows plugin so it’s not overprocessed, it’s super raw.

That suits this plugin super well, and that’s why the AU-only High Impact has been a secret weapon for many people for years—and now it’s out for Mac and PC VST.

A word about the ‘secret weapon’ thing: I hate that. Do as I do, and communicate openly. Airwindows plugins are not preset things that you hide somewhere to add magic sauce to your mixes. They require intention, and there’s no one right way to use them: Airwindows plugins are like if a certain mic modeler you can rent that offers ‘silky expensive microphone models’ had just a blank ugly faceplate with just one knob, ‘silky’. And you could use it as a guitar stompbox if you wanted, not even a microphone anymore, and it was no longer connected to a ‘magic gear item’ so you’d have to ask, ‘HOW silky does this sound need to be, in my mix?’ because there was no one right answer.

That’s what Airwindows is like. For High Impact, read ‘raspy’ or ‘mean’ or ‘grindy’, whatever describes the sound for you. Now you’ve got an extra parameter: instead of just bass, treble, loud, soft (or even fat and thin) you’ve got ‘aggro’ on a knob. That can relate to any bit of audio you’re working with… and your ‘secret sauce’ is not the plugin, but your sense of taste (or tastelessness) in using and abusing it. So, don’t keep Airwindows plugins a secret weapon. I hate that. Tell people what you’re using, so I can get more supporters and keep doing all this, on a bigger and bigger scale.

Speaking of which, I have a Patreon milestone! As of a couple days ago, I hit $600 a month, and I’ve recently changed that to be the point where I start releasing the Kagi catalog! Now, people sometimes bail as the first of the month rolls around (and also I don’t get paid quite the full amount shown). So, it’s possible this milestone will go poof as we reach May, in which case we’re still waiting. BUT, if the dust settles and it’s still over $600 going into May, I will put out Iron Oxide 4 (the second most popular plugin I have EVER made) as free AU/VST!

(oh my God, I look so young in that video o_O )

If I’m still over $600 when May begins, you get THAT plugin free. My hope is that, as I reach this stage, people get more of an idea of what’s possible out of my Patreon project. All this time, I’ve been putting out more than 47 plugins entirely from the ‘freebie pile’, and not touching the ones that kept me in business a decade. Now, we start to get into the serious ones, the ones worth $50 to a lot of people. I’ve even drawn up a timeline on the Patreon, showing when each plugin will come out if I stay above $600. (if I clear $1000 they go twice as fast and I’ll revise the timeline accordingly!)

Here’s where things REALLY get interesting. Hang on to your DAWs, because we’re about to go full warp drive :)

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