Airwindows Interstage: Mac/Windows/Linux AU/VST

VST, AU, etc. plug-in Virtual Effects discussion
jinxtigr
KVRian
902 posts since 7 Apr, 2007 from Bellows Falls, VT

Post Sun Aug 18, 2019 12:24 pm

and here's the video, uploaded later that night!
https://www.youtube.com/watch?v=v8QEovWdL5I

TL;DW: Interstage is a subtle and sophisticated analogifier.

Interstage.zip(341k)

So here's a first. Today, I'm more reliable than Google. I have a video, but my ability to log in to YouTube is broken. (Yesterday, it was my ability to log in to Google Docs on a doc I was invited to edit.) So, my demonstration goes unheard, because I can't sign in and upload it.

And will that stop us? NO! :D

Interstage is one half of an experiment. I pitted my ability to use my weird techniques (interleaved IIR, slew limiting, etc) against my new biquad filtering techniques, in the battle of the bandpasses. The biquads could give me total DC rejection and total rejection near Nyquist. My more distinctly Airwindows tricks could give me new sorts of nonlinearity and tone. Which would win?

This isn't called 'Biquadstage', so that might be a bit of a giveaway.

Interstage isn't a loudenator. It doesn't really clip (though it does go dark as you push the highs harder, in a way I've never done before). It doesn't even preserve the output peaks of heavily limited material: it'll reshape lows in such a way that the peaks might go up slightly as the deepest lows get rearranged, and it doesn't really eliminate DC offset either. So what does it actually do?

*deep breath*

Two level total of three pole IIR highpass which subtracts a pre-averaged sample and slew limits (all right, clips) against not the direct signal but the initial stage IIR lowpassed reference point used as part of the highpass. Oh, also the average it uses isn't the previous input sample, but the slew limited highpassed output.

*crickets*

Bet you wish you had the video, now :D and I am NOT making that up. That's literally what it does, you can see the code (that, too, is up just fine: only the video is on hold)

What does it sound like? It sounds like running through an optimal analog stage. The lows are reshaped in a characteristic way for a capacitor-coupled circuit that still allows extended lows: this doesn't suppress much if any extreme bass. It just massages it a bit. The highs run into active component electronic limits, but unlike other approaches (Channel for a bit of grit, Acceleration for ultra-clear) this is restricting treble slews based on the general amount of energy in the circuit. So it goes darker in a peculiarly analog-like way I've not done before, sounding still clear and trebly for most audio, but confining the craziest most digital-sounding treble swings into a zone that sounds like hardware. And this is without thousands of math operations of heavy processing: unlike overprocessed analog modeling, this one nails the 'energy coming out of analog circuitry' without blurring or thinning the audio at all. If you don't need what it's doing you'll hear no change at all. Only when 'excessively digital bass and treble' show up to interfere, does Interstage kick in.

I'm pretty sure Patreon is still up, so what you should do is what you should usually do: don't take my word for it or rely on my peculiar demos. This time, you can't even if you wanted to! But you can download the plugin and try it. Throw it on something, preferably something you'd like to make a little more analog-ized, and see if you can pick out the differences. Interstage does not distort or saturate, so it shouldn't change your gain staging or the density of your tracks. It simply focuses stuff a little for you, in the way that real analog circuitry inevitably does, and it's a new flavor on that theme. It's designed to work optimally at any sample rate you give it, and guaranteed not to diminish any of your tones (unless those tones require strangely artificial sonics that can't exist in nature: if so, put this on your OTHER tones and you'll have a nice contrast).

Wish me luck following up with the video when YouTube allows… and I hope you enjoy Interstage!
Last edited by jinxtigr on Sun Aug 18, 2019 7:37 pm, edited 2 times in total.

Thavma
KVRist
292 posts since 29 Apr, 2014

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Sun Aug 18, 2019 2:02 pm

Why not a control to boost - drive it harder so it introduces some harmonics of somekind? :D

jinxtigr
KVRian
902 posts since 7 Apr, 2007 from Bellows Falls, VT

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Sun Aug 18, 2019 2:40 pm

Thavma wrote:
Sun Aug 18, 2019 2:02 pm
Why not a control to boost - drive it harder so it introduces some harmonics of somekind? :D
'cos it can't: it has no saturation and generates no harmonics. The amplitude-dependent stuff is purely slew-related and can't generate harmonic distortion in the normal way :)

cantaloupe
KVRist
44 posts since 31 May, 2017

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Sun Aug 18, 2019 2:48 pm

Very mystical plugin. I'd love to read and hear more about what it does, how it does it and what material is needed to "enable" it because i can't notice anything after 20 minutes of blindtesting on different material. That text makes it seem very appealing though. Hopefully i'm able to educate my ears in the process.

jbarish
Banned
483 posts since 28 Apr, 2017

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Sun Aug 18, 2019 6:02 pm

jinxtigr wrote:
Sun Aug 18, 2019 2:40 pm
'cos it can't: it has no saturation and generates no harmonics. The amplitude-dependent stuff is purely slew-related and can't generate harmonic distortion in the normal way :)
Interesting. PluginDoc shows a fair amount of harmonics being generated. I suppose PD could be reading it wrong.

jinxtigr
KVRian
902 posts since 7 Apr, 2007 from Bellows Falls, VT

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Sun Aug 18, 2019 6:27 pm

jbarish wrote:
Sun Aug 18, 2019 6:02 pm
jinxtigr wrote:
Sun Aug 18, 2019 2:40 pm
'cos it can't: it has no saturation and generates no harmonics. The amplitude-dependent stuff is purely slew-related and can't generate harmonic distortion in the normal way :)
Interesting. PluginDoc shows a fair amount of harmonics being generated. I suppose PD could be wrong.
Perhaps I can rephrase that as 'it has no soft-saturation or hard-clipping stages outside the slew clipping, which is not being done in a simple way'. I'd be surprised if it cleanly generated any sort of harmonic in the normal sense. It'll generate sounds and interact with the audio nonlinearly, which isn't quite the same thing.

BTW, working on getting the video up if a thunderstorm doesn't take my computer out :) I got access! May have been browser issues, though some YouTube outages are being reported local to me.

User avatar
andymcbain
KVRist
246 posts since 10 Jan, 2017

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 4:33 am

I admit that I had to do a null test to figure out what this one was doing - it became a little clearer after that!

I think it'll become more obvious with cumulative effects over multiple tracks :)

s28
KVRist
311 posts since 9 Aug, 2017

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 4:49 am

jinxtigr wrote:
Sun Aug 18, 2019 2:40 pm
Thavma wrote:
Sun Aug 18, 2019 2:02 pm
Why not a control to boost - drive it harder so it introduces some harmonics of somekind? :D
'cos it can't: it has no saturation and generates no harmonics. The amplitude-dependent stuff is purely slew-related and can't generate harmonic distortion in the normal way :)
Does changing the input change how the slew kicks in then? If so input/output and dry/wet would make sense. They should be on all of them really, dyno and mojo for example are missing output and dry/wet, I know you chose to not include them but it feels like they're missing in use, massive gain boosts with mojo. Your plugins with all of those on board get used every time. I don't get exact with matching levels, I just go by ear but having extra gain plugins in the chain to do that feels a bit unnecessary, I do it still tho and it's not the end of the world.

As to the sound of this plugin - a nice tightening of the sound that is different to anything else you've put out and anything else I own, will be getting a lot of use out of this so thank you!

User avatar
Vortifex
KVRian
1408 posts since 1 Sep, 2016

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 10:10 am

No disrespect intended because I know Chris is literally a wizard. But I honestly can't tell the difference when this thing is on or off.

sleepcircle
KVRian
691 posts since 28 Nov, 2016

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 12:14 pm

the vst version reacts EXTREMELY POORLY to being run at 96khz. at 44100 it's fine, but at 96000hz, feeding it a moderately hot signal causes it to produce a noise like tearing fabric.
was this a foreseen issue?

Thavma
KVRist
292 posts since 29 Apr, 2014

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 12:56 pm

I do feel with some of the plugins that you must have bionic ears to hear what Chris is talking about! :D Sound is hard to realise if its soooo subtle, except if you are a very experienced "hearer"

s28
KVRist
311 posts since 9 Aug, 2017

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Mon Aug 19, 2019 5:33 pm

On monitors I probably wouldn't hear this but on my headphones I can pick it out and it seems useful, will have to try it in a mix though.

Slaapstadseun
KVRist
158 posts since 9 Jan, 2011

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Tue Aug 20, 2019 12:25 am

I can see what this effect does in a freq analyser, but I cannot hear what it does.

jinxtigr
KVRian
902 posts since 7 Apr, 2007 from Bellows Falls, VT

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Tue Aug 20, 2019 6:36 am

Thavma wrote:
Mon Aug 19, 2019 12:56 pm
I do feel with some of the plugins that you must have bionic ears to hear what Chris is talking about! :D Sound is hard to realise if its soooo subtle, except if you are a very experienced "hearer"
I'm using a MOTU 16A (and designing on a Lavry Black DA10) and using Channel Islands monoblocs for amplification: in design the Lavry is driving heavily modified Sennheiser HD600s. It's kind of like Bob Ohlsson's experience in hearing dither: it's not all the ears, sometimes you have to upgrade your signal chain so you can hear what you're doing, and 'golden ears' are only part of the equation. There's lots of stuff I could do to my monitoring where I'd just stop being able to hear what was happening, so I stick to what's really transparent.
sleepcircle wrote:
Mon Aug 19, 2019 12:14 pm
the vst version reacts EXTREMELY POORLY to being run at 96khz. at 44100 it's fine, but at 96000hz, feeding it a moderately hot signal causes it to produce a noise like tearing fabric.
was this a foreseen issue?
I'm looking at the code and can't see how that'd be happening. No, absolutely not, didn't expect any such result or I'd have fixed it. What's up with that? I have yet to hear it, myself. Maybe I shouldn't be scaling threshold? Is it even crazier at 192k?

sleepcircle
KVRian
691 posts since 28 Nov, 2016

Re: Airwindows Interstage: Mac/Windows/Linux AU/VST

Post Tue Aug 20, 2019 7:59 am

jinxtigr wrote:
Tue Aug 20, 2019 6:36 am
Is it even crazier at 192k?
Yup, you called it.

Take a listen.

At 44.1k, 96k, and 192k

https://drive.google.com/open?id=1C9Hck ... zke2DFXt1x

Return to “Effects”