PreSonus Blog

Resonator FX Chain


This FX Chain complements the Tightener FX Chain presented in the October 25, 2019 Friday Tip. Whereas the Tightener reduces the presence of the key center in a piece of audio, the Resonator enhances the key center by adding resonance. The download at the end includes twelve Resonators—one for each key.


The heart of each Resonator FX Chain is two delay lines whose period correlates to a particular key, and are tuned an octave apart from each other. Mixing the delayed, resonant sound with the dry sound imparts a sense of pitch, which can be useful with unpitched instruments (such as percussion) to blend in better with melodic instruments. It can also help create a sense of pitch for drums that aren’t tuned properly, as well as emphasize any instrument’s key center.


For example, suppose it’s hard to get a shaker part to fit in a mix because its level is either too high and stands out, or is too low and sinks into the track. Adding a feeling of pitch may allow mixing the part a bit higher, while also having it blend into a mix more seamlessly. If taken to an extreme (and the FX Chain allows for that!), the Resonator has special effects potential for sounds like “cylon” voices, or tuning reverb.



The Controls


Figure 1: Each Resonator has six controls; the Resonance control is the most important one.



The controls (Fig. 1) are pretty straightforward, and cover the full travel of the Analog Delay controls. There’s no need to tweak any Transform curves.


  • [key name] Resonance varies the mix of the resonant and dry sounds. Most of the time, mixing in even a bit of resonance may be all you need.
  • Sharpness adds feedback to create more intense resonance.
  • Width determines whether the resonance is stereo or mono. Most of the time, you’ll probably want to leave this control fully clockwise.
  • Saturation, Low Cut, and High Cut controls are “because we can” controls. You may not use them much, but hey, an FX Chain allows for eight controls…so why not?



Striking the Right Chord


You can also use the Resonators to impart the sense of a chord by sending a sound to FX Channels, loaded with appropriate Resonators. Fig. 2 shows a shaker part acquiring a more melodic vibe via resonators for the keys of D, F#, and A. This produces a D major chord tonality.

Figure 2: Sending the audio from a shaker to three FX Channels “tunes” the shaker to a D major chord.


Although I came up with this mostly to process unpitched sounds, I’ve found it has other uses as well. For example, with an acoustic guitar part, a Resonator can add a vibe that’s not unlike the drone strings on a sitar. The best implementation I’ve found for this is putting the Resonator in an FX Channel, and automating a send so that the resonance is added only in certain strategic parts. And of course, if you want to get crazee, you can always turn up the resonance and sharpness, and do cylon voices. Fun stuff!


Download the 12 Resonator FX Chains Here.