APO crackling and cutting out when using VST plugins

[sean mason]

Whenever i turn on any VST plugin, apo starts crackling.
I have tried reinstalling, using different VSTs, though nothing has worked.

(edit) it seems to only crackle on certain applications that pick up my mic, while some work fine, others sound very glitchy.

[Juha]

Could you attach your config file(s).

[Peter Verbeek]

And what are you using for equalizing? If using the graphic eq (the default for eq-ing in the Configuration Editor) then this could also be the cause of crackling.

[Icye]

I've run into the same problem even after reinstalling Equalizer APO, including the crackling and being limited to only certain applications.

The Windows (10) audio loopback works fine, as does OBS Studio (v29.1.3) and previous versions for the past year.

Discord (Stable v213695 and previous versions) and VMWare Horizon Client (v2212 Build 8.8.0) both experience this crackling issue.

Here is a config file I made back a while ago before I learned what VSTs were that experiences these problems: (it has no crackling until any of the below filters are enabled / un-commented)

Preamp: 0 dB

; Roll off low-end bass frequencies
; Filter 1: ON HP Fc 50 Hz Slope 6 dB/octave

; Reduce muddiness & boominess
; Filter 2: ON PK Fc 200 Hz Gain -2.0 dB Q 2.0
; Filter 3: ON PK Fc 400 Hz Gain -2.0 dB Q 2.0

; Brighten the vocals for air & sparkle and make them more delicate
; Filter 4: ON PK Fc 3000 Hz Gain 2.0 dB Q 1.5

; Add presence to the vocals and make them more gentle
; Filter 5: ON PK Fc 5000 Hz Gain 0.5 dB Q 2.0

; Reduce sibilance with a de-esser
; Filter 6: ON DS Fc 5000 Hz Threshold -35 dB Ratio 2.0 Attack 5 ms Release 50 ms

; Boost the core vocal frequencies
; Filter 7: ON PK Fc 8000 Hz Gain 1.0 dB Q 1.5

Additionally, I've attached my current config that works fine in the Windows audio loopback as well as OBS but struggles in Discord & VMWare Horizon Client, just like the config above.

Edit: I should add, that enabling any single one of the VST plugins (or any combination / all of them, of course) will start causing the crackling, but having the entire config file commented out will stop the crackling

[Peter Verbeek]

Usually biquad filters like the ones of your config are flawless (although DS isn't an Equalizer APO filter). But there can be issues by VST plugins. We don't know why. Unfortunately the developer of Equalizer APO can't say what's going on as he isn't active on this project.

being limited to only certain applications.

It could be that some apps use some different audio techniques bypassing Equalizer APO or any APO (sound enhancement) for that matter.

Using Equalizer APO in VMWare isn't something I have experience with so I can't say something decent about it.