Speaker Volume Decreased after Software Update

[Rasik]

Before 6.0 my phone speaker sound was fabulous but after update of 6.0 speaker volume is decreased.

[Kuzya92]

Hello. At me such problem, updated the sony xperia m4 to android 6.0.1 and after that at me the sound of a musical speaker has decreased in half, how it can be corrected?

[Electronic_Project]

I've excactly the same problem.