‘Sada’ is a service that enables the caller to hear a tone that you chose instead of normal tones, which could be a song, nasheed, Quraan, etc. Bear in mind that the recipient does not hear this tone.
This service allows one to choose the ring tone which the caller hears.
If the ring tone chosen is a nasheed that has good meanings, or wisdom, or du’aa’ and the like, then that is something that is permissible or mustahabb, so it is permissible and there is nothing wrong with it.
The ring tone should not be the voice of someone reciting Qur’aan, because the Qur’aan is the word of Allaah, so it must be venerated and respected in the manner that befits it, and it should not be used to fill empty spaces or to distract people. The caller may be distracted or speaking to someone, so he will not listen and pay attention to the Qur'aan, and he may want to end the call; all of these are things which are contrary to respecting the Qur’aan.
For more information please see the answer to question no. 105479.
And Allaah knows best.