My zenfone6 bottom speaker makes rattleing sound at full volume at some nodes is it a quality issue?

[prototype1036]

I recently bought zenfone6 I have a issue with bottom firing speaker it creates a lot of rattleing sound at some nodes while Playing any song in YouTube is this a hardware issue with only mine or any one is facing it if anyone is facing is raise your tone it can fixed by software update to DAC I feel Asus will fix this