On my PS3 via HDMI cable with my Onkyo TX-SR875 AV Amp I get true HD 5.1/7.1
surround sound.
But on my PS4, outputs only a 2.1 signal via HDMl; I have swapped
cables and inputs between the PS3 & PS4 and it makes no difference.
On the PS3 there are options to output with different audio...