Here's one! This is one of the basses in a drumstep ID I'm working on.
https://clyp.it/baymk3amBasic scream bass; sounds kind of like the drop in
Knife Party's remix of "Crush On You". Made using Harmor. For post processing, some stereo shaping might be necessary to bring the sub down to mono, but you can just cut the sub out and add your own.
How to make it:
Start with a supersaw. I used 4 unison voices, with moderate detune (default should be fine). I mapped the pitch thickness to an envelope, so it starts detuned, then once all the unison voices are out of phase, they get closer together. This just adds a little squelch and stereo, you don't really need unison for it. Tune it down 2 octaves with the pitch slider, Freq divider, or just playing really low.
Harmonic prism, with the default prism shape, and turn the Amount knob just a tiiiiny bit to the left. This is where the squelch comes from. Knife Party's basses have a lot of interesting stuff happening in the highs, something I've always admired, and this channels just a little of that. This is something you can only do with additive synthesis; the prism moves each harmonic just a tiny bit out of sync with each other over time, but not so fast that they sound out of tune.
The screaming sound comes from really emphasizing just a few harmonics. The best way to do that is with a comb filter. Harmor doesn't really have a comb filter, but it has a good approximation of one with the "Deeper" phaser setting. Change the phaser mode from "Classic" to "Deeper", set it to Harmonic ("harm"), turn the mix all the way up, turn the width almost all the way up, zero the speed, and mess with the offset until the first peak is somewhere in the mids.
Map the phaser offset to an envelope that starts at the bottom and rises up to the middle, so the scream rises up. And while you're here, do the same thing to the main pitch. If you want to get a sub out of this too, raise the harmonic protection ("prot" slider at the top) a little. To finish, add Log distortion (amount about halfway, filter all the way up) and reverb.
To get the "dipping" effect, turn on legato, hold a note, and play a lower note (more than an octave down) really quickly over and over.
Here's how it works:
Technically, this is a bass, but when you start with a saw, you end up with a range of harmonics that spans the whole audible spectrum (pretty much). The phaser cuts most of them out, starting at the bottom, and leaves just a few peaks. These peaks aren't single harmonics, though; they're clusters of a few harmonics close together.
Quick psychology lesson: what we perceive as "screaming" comes from
nonlinear sound. These are sounds that don't act like normal sounds, instead of being a fundamental and overtones, all neatly organized at multiples of each other. Horrified screams are nonlinear. So's the sound of nails scraping on a chalkboard.
By cutting out the lower overtones, this sound tricks the listener into thinking the fundamental is way higher than it really is; instead of being down in the sub bass, it's off in the mids. But because each "peak" is really a few different harmonics, it sounds nonlinear.
I'll update this if anyone thinks that explanation sucked.