To play with no limitation Deezer track within Spark, you need to subscribe the premium offer on Deezer.
There are limitations if you are playing tracks with a free account, one the limitation is that Spark will be able only to play 30 secs.
You can find details on subscription plan on Deezer here
Products: Phantom | Version: ALL
Setup: Solo, Duo or Mutli-room | Source type: Deezer
Creation date: 03/08/2016 | KB article ID: SP0203