I just bought a brand new S4 Active and I am very upset with an echo issue for my correspondents but not for me.
When I remove back cover or if I activate loudspeaker, echo disappears for my correspondent.
I have tried unsuccessful configurations with noise reduction enabled and disabled, personalise call sound options...
I think there is two microphones, one in the bottom and one on the top.
Maybe that only one (top one) is activated when loudspeaker is on, and when it is deactivated both of them are enabled (the one on the top to reduce noise environment and the bottom one for voice)
Maybe that this is just a software issue?
Does anyone have the same problem?
And does anyone knows how to fix it?