Sony Receivers: "Auto Format Decode" vs "Normal Surround" (1 Viewer)

[SteveK]

What is the difference between "Auto Format Decode" (AFD) and "Normal Surround" on Sony receivers? I had been using AFD for both my DVD player and my DishNetwork connection. AFD would give me DD or DTS on DVD, and DD or PCM on DishNetwork (I have the PVR501 with optical digital). One of the shows I frequently watch is "Babylon 5" on SciFi, which is recorded in surround sound. Wondering why I was not getting surround sound with AFD, I switched to "Normal Surround" and was pleased to discover that I now have surround sound. I can use normal surround for Dish and AFD for DVD, as my receiver can "remember" which sound field was last used for each input.

I had been using "AFD" on Dish because the impression I got from reading the manual was that it would automatically decode the sigal and that I would get the appropriate sound, whether mono, DPL or DD/DTS. The description for "normal surround" implies that it does essentially the same thing. Even when I have it on "normal surround", it still seems to decode DD/DTS correctly, gives me DPL on some programming and mono (center channel only) on other programs. Previously when I used AFD, I would get audio from the left front and right front only on PCM material.

What is the difference between "AFD" and "normal surround"? I don't use any of the other "sound fields" as they seem like a gimmick, but normal surround doesn't seem to electronically manipulate the sound. Would I be better off using normal surround for Dish and AFD for DVD?

Sorry for the lengthy post, but I thought I had everything set correctly and now it appears that I don't. Any information would be sincerely appreciated.

Thanks in advance.

Steve K.

 

[Charles Gurganus]

Simply put, the AFD is searching the digital inputs to decode. If you don't have a digital signal (5.1) but still want surround, thats when you go to the Normal Surround mode. It (AFD)will not take a digital 2.0 format and convert it to pro logic. Thats when you switch to the non digital Normal Surround mode.

 

[SteveK]

Charles- You're right, that was simply put. And it's just the kind of explanation I needed. The manual didn't make that very clear, but your response did.

Thanks again for the help.

Steve K.