Upgrade to the latest version of
Music Speed Changer to use external equalizer and effects apps. The newer versions of Music Speed Changer now work better with external equalizer and effects apps.
You can also try turning off the ‘Use native audio library’ option under Advanced Options in Settings. The AudioTrack library used in that case tends to be more compatible with equalizer and effects apps that apply effects to the global output mix.
Turning off ‘Use native audio library’
Open the Player Main Menu
Select Settings
Scroll down and select Advanced
Uncheck Use native audio library