To confirm I'm using Spotify. Believe the eq is global so the app you use is irrelevant?
Looks to me like the Pro version is still paid for https://play.google.com/store/apps/details?id=com.devdnua.equalizer - I'd assume that it just removes the ads but I haven't tried it yet.Also, there is a Pro version. Used to be paid, but now its free. I dont think there is a difference.
Which single are you using?Having used it for a few days I do not think the equaliser fx does anything that the built in one does not it is just easier to adjust.
There is just something a little harsh to the sound for me with the eq off. It is hardly terrible but having heard other phones it is hard to un-hear!
I maybe need to get braver and try viper. I am still holding off on selling that V30!