A high pass in front of the lowpass for a powerfull bass. What is the explanation on this?

[waltercruz]

"Can you give us a little production tip or do you have a secret function in one of your plug-ins?
In any synth, try a highpass filter in front of the common lowpass. Keep the highpass at a very low frequency, add – if possible – a little resonance. As paradox as this sounds, that can boost your bass big time!"

http://www.noizefield.com/interviews/ta ... kmann-u-he

Urs talks about it on other topics too.

Just forgive me if I'm being a bit naive, it works, but someone can explain the reason? I'm failing to see.

[Neuropath]

IIUC most filters have a 'bump' at the center/crossover frequency, or just the other side of it. The resonance increases this.

So a HighPass set at 50Hz would filter below that, and there would be a bump at roughly 60Hz-ish.

That's my late-night not-very-technical explanation. I do know it works though- quite well!

[xx JPRacer xx]

Exactly like Neuropath said. The nice thing about the filter is it can follow the note, compared to a EQ boost. So you put the filter (100% key follow) where you like, put some resonance to boost and that's it.

[trance_lucent]

It isn't just some bass boost from resonance, there is also some phase distortion from highpass that colours a sound a bit after it passes through the second filter: most modern filters have a non-linearities of some sort (modeled in different ways, simple post-waveshaping in the simplest cases) which colour the sound affected by distorted phase (due to highpassing) resulting in a more "analogue" feel and bass-booming.

[waltercruz]

Nice! Great explanations from everyone

[Chris-S]

Also I think removing the non-audible freq range (0-20 hz) gives some room for the audible bass range.

But be aware that for some styles (EDM, cinema) also the sub freqs are needed.

[noiseresearch]

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