Setting NooxZoide Pro to work with Spotify, or Viper4Android NON-ROOT alternative

Hi! I wanted to use Viper4Android but since I've just bought this new Moto G Plus, I didn't want to root it and mess with the guarantee. So, I'm trying to use NoozXoide, but it does not seems to work correctly with Spotify... It changes absolutely NOTHING on the sound. The odd part is that, sometimes, specially when I've just set NoozXoide and then I open Spotify, the musics start REALLY loud for like, 1 sec, and suddenly the volume drops... I'm not sure if I'm miss-setting something... Could you guys help me?
(Oh, also, since I've never been able to use NoozXoide (I've also tried with my old S4 Mini, like, 6 months ago), I don't know the best settings to listen to the most authentic (original recording-like) and subwoofered bassy music... could you also gimme some tips on this? thanks [​IMG] )

ALSO.
If there's ANY way to install Viper4Android without messing with my phone's guarantee (it seems that the only methods require either root or Selinux mod, right...? And doing those usually cancel the product's guarantee), or at least any good alternative to V4A, I'd be glad you guys could help me.
Thanks!

ANY one?