The VideoLAN Forums

start vlc
tools > preferences > show settings: ALL
interface > main interfaces settings > show advanced options: ✓

audio > general audio settings > force detection of dolby surround: ON
audio > general audio settings > stereo audio output mode: DOLBY SURROUND
audio > audio resampler > speex resampler > resampling quality: try between 8 and 10
audio > audio resampler > src resampler > sample rate converter type: SINC FUNCTION (BEST QUALITY)

input / codecs > advanced > file caching (ms): 600
input / codecs > video codecs > ffmpeg > decoding > skip the loop filter for h.264 decoding: ALL
input / codecs > video codecs > ffmpeg > decoding > hardware decoding: try AUTOMATIC or DISABLE
input / codecs > video codecs > ffmpeg > decoding > threads: 2

video > general video settings > grayscale video output: ✓
video > filters > video filter module > gradfun video filter: ✓
video > filters > swscale > scaling mode: SINCR
video > output modules > video output module: AUTOMATIC (for 4K fix use OPENGL VIDEO OUTPUT)

tools > effects and filters > audio effects > equalizer > enable: ✓
try this equalizer settings (not mine source youtube)
PREAMP: 3.9 | 60Hz: 8.3 | 170Hz: 10.5 | 310Hz: 5.5 | 600Hz: -3.2 | 1KHz: -2.4 | 3KHz: 1.4 | 6KHz: 4.8 | 12KHz: 8.1 | 14KHz: 8.7 | 16KHz: 8.9

if this is the wrong forum please let me know, any feedback on the fixes are welcome