My loudspeaker sounds bad only the one on the top

[1994bys]

El altavoz de mi movil el de la parte de ariba suena mal y no se por que si antes funcionaba bien 

My loudspeaker on the top part sounds bad and I do not know why it worked well before

-GT

[azzido]

to be honest I sent my device on warranty since my bottom speaker stopped working completely. 
I tries restarting it or even software repair using Xperia companion, without any luck. 

I was checking it using different apps and also tested it using installed diagnose tool and service tests. 
The only option was to send it on warranty. Awaiting to receive it back soon.