[PS4]Having an issue with sound.

[BLaCKnBLu3B3RRY]

hello. i have a 5.0 home theater system. it can support the Dolby and DTS formats. i currently use DTS, but have also tried Dolby. and the problem is is that the game is only sending dual-mono. even through the TV it is possible to get stereo sound. the receiver says DTS is on and running, but i only hear dual-mono. i am outputting from the PS4 directly to the receiver with an optical link.

all-in-all, i can't figure out what is wrong. output is fine for Netflix. and Grand Theft Auto 5 works just fine too.