Default settings for audio playback cause distortion and/or 'ducking' effect
VLC v3.0.3 iOS v11.2.6
Default audio playback settings suffer from 'ducking' effect, obvious volume dips (compression/limiting artifacts) after large transients.
I noticed that VLC's default EQ settings have the "Preamp" above 0, and that lowering this control seems to reduce the amount of compression/limiting that is applied.
By default, no digital processing should be applied. The "Flat EQ" setting (default setting) should not boost the overall volume, as it seems to trigger the onboard compressor/limiter processing.
I posted about this in Reddit and found a VLC for Android user having a very similar issue, although they described the sound as having 'distorted bass' until they brought down the Preamp.
The most annoying part is that the EQ settings reset after each play, so every track needs tweaking to avoid the ducked or distorted playback.
In its current state I can not rely on this app for playback of my mixing and mastering sessions.