Equalizers are not working

I have been using Equalizer+ and a while back it stopped working. I was told that it might be interference with other apps, so I deleted/disabled all other music apps (except default music player) and it didn't work well. I referred to https://android.stackexchange.com/questions/87963/android-5-0-lollipop-music-equalizer and I could not find **MusicFX** anywhere in my apps. It doesn't work with Equlizer+, Bass Booster EQ, Shuttle, Rocket Music Player and any others wither. I have ran out of options and I really want sound quality back. My phone is **LG Leon** and it is running Android Lollipop (v 5.1.1).