Iphone 6s distortion

[nameste]

Hello ,i compare the ringer between my new 6s and with my 6s plus .6s plus has lower but clear sound but 6s has crackling sound and its louder.Weird thing is there is no crackling with the 6s when the battery is @%100 but its starts to crackling lower than %70-80.Is this a hardware problem?What should be the problem?

 

[C DM]

Do you have vibrate enabled with the ringer as well?

 

[nameste]

Do you have vibrate enabled with the ringer as well?

Yes , but it does the same without vibration

 

[nameste]

so nobody has the same problem?