humble: a compressor

[notwa]

humble was meant to be a very natural-sounding "analog" compressor, going off some advice on kvraudio or maybe gearslutz. it turned out quite the opposite. cranked up, this thing does disgusting things to drums, but on its default settings, can tame vocals pretty tamely.

features 4x oversampling. not quite linear-phase unfortunately, so a wet/dry knob is included as a cleaner alternative to parallel compression. has some parameter smoothing on the gain knobs. the attack/release is somewhat based off molot.

cba to give this a proper interface or write-up. i've been sitting on this for too long already.

download

[Quest The Wordsmith]

Gotta try this on vocals...

[Anomaly]

Hello,

I can certainly hear molot flavor in the attack part, which I like very much. Personally I prefer this for drums and bass with long attack, but vocals sound good too. I think it's quite nice sounding compressor. The only criticism from me comes from the "unconventional" operation of controls compared to the norm you expect from a compressor. But these things are never carved into a stone.

PS: I wonder if your oversampling method could work with the limiter I recently put out..?

[notwa]

yeah the controls are unconventional, but all you need to know is left is less and right is more. having them range from 0 to 10 could be less overwhelming, but that makes them even more ambiguous. i also considered measuring what the values actually represent, but that felt too serious for a fun little project like this.

you can use the oversampling code for whatever you like, but be aware of phase issues of the IIR design, especially peaks being different after decimating. as far as i know, this means you have to do final brickwall limiting in the output sample rate.

fyi the coefficients for the 2x oversampler were generated from this C program, but don't ask me how it works exactly. the sources listed by the original (PolyphaseIir2Designer.h, hiir) are two dead links and a non-freely available paper.

References:

* Polyphase Two-Path Filter Designer in Java
Artur Krukowski
http://www.cmsa.wmin.ac.uk/~artur/Poly.html

* Digital Signal Processing Schemes for Efficient Interpolation and Decimation
Valenzuela and Constantinides
IEE Proceedings, Dec 1983

* A Hilbert-Transformer Frequency Shifter for Audio
Scott Wardle
http://www.iua.upf.es/dafx98/papers/WAR19.PS

the 4x oversampling then works by taking advantage of the already steep 2x filter and lazily (24dB) rolling off the frequencies past 22kHz. i believe the benefits from this stage come from less mirroring of higher order harmonics, more room to breath so to speak; not so much attenuation.

do note that the very top end does alias quite a bit, but this is way out of the audible range when running at 44100Hz. this is due to the -6dB point (or maybe -3dB i can't remember) of the polyphase filter being directly on nyquist and not slightly before. this is a limitation by design; the reduced, faster code of halfband filters is well worth it.

honestly, oversampling off sounds fine to me. though keep in mind i don't have anything near studio gear, and the harmonics graph is undeniably prettier. compare (1x) against (4x)

[Anomaly]

...but be aware of phase issues of the IIR design, especially peaks being different after decimating. as far as i know, this means you have to do final brickwall limiting in the output sample rate.

Yes, this was the issue with my initial testing too. I think it's a bit problematic with a limiter, where you can't allow anything over 0dB. On the other hand Using a brickwall or clip @ output sample rate defeats the purpose of OS in the first place as I was hoping to gain access to the inter-sample peaks which become a problem when you limit at lower sample rates.
I suppose I should do more research on OS implementation...

[Fergler]

Nothing wrong with the sliders to me, I don't think converting to 0-10 would help either. I prefer dB when it comes to EQs or Compressors.

Sounds neat on vocals!

[Badmotor]

Very nice. Like you say - sounds great on vocals. Getting a nice 'pillow' effect here.


edit: and drums! Sorry for just repeating what everyone else has said.

[citizenkeith]

Can somebody post a download link for this effect? It's not in the stash, nor is it available via ReaPack.

[notwa]

whoops, i forgot that dropbox doesn't allow direct linking anymore.
i've reuploaded it on my personal server: https://eaguru.guru/t/humble
necessary include file: https://eaguru.guru/t/os-2-halfband.jsfx-inc

i dug up the old screenshot, even. note that this is of version 1:


i've learned a lot since making this (though mostly outside of DSP), so if i ever get around to it, i'd like to make the oversampling linear-phase, reimplement auto-compensation, and maybe write a VST version.

[mschnell]

Seems like it would make a great addition to ReaPack.
-Michael

[citizenkeith]

Originally Posted by notwa

whoops, i forgot that dropbox doesn't allow direct linking anymore.
i've reuploaded it on my personal server: https://eaguru.guru/t/humble

i dug up the old screenshot, even. note that this is of version 1:


i've learned a lot since making this (though mostly outside of DSP), so if i ever get around to it, i'd like to make the oversampling linear-phase, reimplement auto-compensation, and maybe write a VST version.

Notwa, thank you!

I recently had a Macbook Pro stolen (a soul-crushing experience). My external hard drive was backed up, but I've found myself searching for a bunch of JS effects, and this was the only one I couldn't find.

Prior to the theft, I had the task of remastering a couple of my electronic releases from 2000, and I was very impressed with the sound and performance of "humble." It really fit the bill for many of the tracks. I'm going to try it pretty soon during mixing.

Linear-phase mode would be a most welcome addition!

Any chance you can put your effects in ReaPack? It's been a life saver for me, and makes updates really easy for the end user.

Thanks again!

[mschnell]

Originally Posted by notwa

whoops,
i've reuploaded it on my personal server: https://eaguru.guru/t/humble

Seemingly the include file "os-2-halfband-jsfx.inc" os missiong.

-Michael

[notwa]

Originally Posted by mschnell

Seemingly the include file "os-2-halfband-jsfx.inc" is missing.

-Michael

whoops x2, here you go: https://eaguru.guru/t/os-2-halfband.jsfx-inc