Questions about "LF" and "band-passed"

There’s a bunch of UGens prefixed with “LF” which is supposed to mean “low-frequency” (e.g. LFNoise*, LFSaw), and most (all?) of them are documented as “non-band-passed”, which I believe means they’re prone to aliasing at higher pitches.

But that all said, I’m still confused what is “low frequency” about them? Usually LF makes me think of LFO, a low-frequency oscillator that’s not intended to be audible itself but can control other effects, flangers, phasers, etc., but these UGens are all capable of producing audio, and certainly at higher pitches/frequencies too (e.g. { * 0.2 }.play). Does LF in this case just mean “ideally you should only use these at low frequencies due to aliasing”, rather than “only produces low frequencies”? Or something else?

I don’t know the history, but my guess is that these were intended for use as a traditional LFO, as a control signal where aliasing isn’t an issue and band limiting isn’t necessary.

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This interpretation, and Scott’s comment, are both correct.

In general, SC allows you to misuse unit generators: these UGens are intended as control signals, but if you want aliasing, you can get it from them (and it isn’t SC’s job to stop you).


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