spectral smoother

(so to say)

(13 Votes)
2.0 (Updated 2 years ago)
December 14, 2018
Reaktor 6
Effect Other


spectral smoother takes the spectrum of a signal and smoothes it out -it literally lowpasses the Fourier transform. It's not very interesting on synths, but on recorded stuff it (heavily) lifts the noise that's buried down (maybe adding some distortion due to the FFT windowing, I'm short on maths there). I use it mainly on voices, to get weird doubling growls or to make traces/bursts of noise that seem to "come from" the base sound.

There are two parameters, each controlled through a spline curve -width and height. Width is the horizontal spread of the smoothing across the spectrum (for any given frequency, 100% width means a bandwidth of smoothing>36.8% equal to the frequency itself). Height controls the mix between the original and smoothed spectra, changing the level of the spectrum valleys with respect to its peaks. Negative height makes the peaks and valleys more instead of less pronounced (the opposite of smoothing); in this case, increasing width makes the peaks more isolated.

The spectral display is just indicative -it shows the smoothed spectrum as sent to the iFFT, which then does its best.

(Thanks to Gabriel Mulzer, Martijn Deluxe and Jan Brähler for the FFT implementation.)

* % is now called width, mix is called height
* Range for width controls set to 0..100 (instead of -100..100)
* Mixing (height) got its own curve; both curves can be scaled
* Geometric (instead of arithmetic) mixing, to allow the use of negative values
* RMS (instead of abs avg) smoothing filter, to avoid a large difference in level between positive and negative height -output level for positive height is now higher than before
* Fixed mode and max settings removed -current version corresponds to relative mode, 100% max of the previous one
* First breakpoint removed
* GUI and automation IDs reorganized
* Many small changes in implementation


Pablo Bastian
1 year ago
Very cool spectral tool! My secret receipe: I use it (both 1024 & 2048) on different field recordings & hit the randomizer to bring up all sorts of noisy washes and textures. Great stuff! Thanks for sharing.
2 years ago
hipassing wasn't a good idea, but i found another way to do the "sharpening". i added a splined parameter, took out some options i never really use, and streamlined a little. the effected parts will now be louder, and the tone may change a bit towards the highs.
2 years ago
true, negative values do nothing per se -they make sense in relation to the offset value. you can have an offset of 100, and all bands at 0 except one at -30; this is equivalent to all bands at 100 except one at 70. the effective values are clipped to 0~100. i guess that, if i'm smoothing by lowpassing the ft, i could sharpen by hipassing it. i'll take a look to see how that works.
Linas Maknys
2 years ago
very cool!
Tim Richter
2 years ago
Really cool effect! I noticed the Smoothing-percentage can be set to negative, but it doesn't seem to do anything. It would be an interesting thing to do because that way you could bring out the harmonic frequencies in your track instead of raising the noise level. Do you have any plans to maybe implement this down the line?
ian ainslie
2 years ago
Love this!
2 years ago
waow. feels unique! respect!
Kimmo Kivelä
2 years ago
Interesting natural smooth fuzziness.