I have a Dell Studio XPS 16 with ATI Radeon 4670 and thankfully has an HDMI output , It used to play properly few days ago and suddenly , it stopped playing audio after i installed Win 8 Pro , but after installing Realtek drivers for ATI HDMI Output it was working again but the output plays only the Center Speaker , none other speaker works not even the sub .
Connections- LAPTOP---HDMI---> Sony TV ---Optical/HDMI--->Sony Home Theater & BD System
Have you tried installing the newest amd driver for your 4670? The driver package for it should have an hdmi audio driver included.
Try this, it should fix the edid
LAPTOP---HDMI--->Sony Home Theater & BD System--->HDMI---> Sony TV
^^ Yeah, no idea why you are going to the TV before the receiver.