TL;DW: Infrasonic is a very clean, plain, high quality subsonic filter, for using inside digital mixes.

Infrasonic.zip(355k)

If you saw my recent post about Ultrasonic… this is the same, but at the opposite frequency extreme! It will nuke DC offsets and reshape thunderous rumblings into specifically 'audible' subsonic rumblings. That doesn't mean it will always make the amplitude of subsonic bass go down: there may be times when it alters the waveform so it peaks higher. But it's the same thing as Ultrasonic: tenth-order Butterworth highpass filter, executed as cleanly as possible (NOT with an internal Console system expanding the tone) using very high resolution math.

Normal audio recordists and people working with analog sources will probably find this does nothing for them. But if you get frisky with DAWs and do weird things in the digital mix, you may just end up producing low frequencies that aren't properly sonic anymore. Normally, you'll be using various highpasses to tune your deep bass for the purposes of your mix, and this isn't for that: it's a more abstract concept of a filter.

If you'd like to neatly excise everything below 20hz and retain EVERYTHING remotely considered an audio frequency, especially if you've got DC offsets coming out of your other digital processing (I've tried to fix a lot of my plugins that do this, but there are other plugins out there which can produce it), then this might be handy. It's also one of the Airwindows featureless add-and-forget plugins, and I've always liked making those: speeds your workflow. No window to open, just put it in the relevant place and you're good to go.

All this is supported by Patreon. I'm busily working on some of my grander Patreon-supported schemes, and it's going pretty well. As always, if you're in trouble please use my stuff and don't pay until later when things are better. If you're doing fine, I appreciate the support, and I hope the things I'm learning and doing are both exciting and useful