I have found the Equalizer class on Android and I'm wondering if there is similar functionality on iOS7+ or is there any other way to achieve similar effects (audio setup for audio playback).
in iOS, Audio Effects, filters, equalizers etc... are implemented as Audio Units. in your case you'll probably want to implement an Audio Unit with component subtype of kAudioUnitSubType_NBandEQ . Refer to the Audio Unit component services documentation for further details. you can find further details here: Audio Unit Component services reference.