TL;DW: Lowpass2 is an unusual-sounding variable-slope lowpass filter.

Lowpass2.zip(353k)

This new version of Lowpass exists to fix a bug, but then I added stuff to it that makes it entirely a new animal!

The existing Lowpass tries to produce the same cutoff no matter what sample rate you use, but doing that meant high sample rates can never use a fully opened filter. Instead, you got roll-off no matter what. Lowpass2 no longer does that: the filter control goes from complete silence to wide open no matter what sample rate you’re at.

But there’s more: Lowpass2 still uses the interleaved IIR filters the original Lowpass pioneered (you’ll notice subtle bleed-through of information near the Nyquist frequency, beyond human hearing, but also the open and involving sound) but now it can use from zero to four poles of filter: so you get a stronger effect, and a sharper roll-off!

And that’s important because with four poles of filter you REALLY hear what the Soft/Hard slider does. This interacts with the filter control (don’t expect the cutoff frequency to stay the same) but what it does is vary the cutoff based on what sample value the input is. So you can either roll off harder for the peaks of the sound… or let ’em through more. Since it’s an IIR filter the effect is gradual, but at four poles it’s really noticeable.

That gives you two distinct tone colors for your lowpassing, plus special effects: in the video I demonstrate how cranking the control to Hard on pink noise can make it sound like wind noise where you’re going incredibly fast. Lowpass2 is ideal for experimental tone shaping, and for sound design.

If this becomes indispensable to you, please jump on my Patreon for an additional $50 a year if you’d have paid that for this unusual tool (perpetual license, forever support, all your computers, you get the source code: you know, normal terms and conditions like that). If you can’t afford it, use the plugin anyway, and maybe one day you’ll be better off :) if you just hate Patreon, I’m working on getting some alternate things in place such as Ko-fi. However, in order to set up Ko-fi to be even comparable to what Patreon does, I have to pay them up front. So please help with the Patreon so I can afford to have a fallback position. Probably won’t ever matter, Patreon is thriving and it is only investor logic that has anyone thinking it isn’t :)