Prologic II in GT4...

[imzjustplayin]

I've enabled Prologic II in GT4 and basically any other game I play on the PS2. I have the PS2 hooked up to my reciever via the optical port and I'm annoyed because when ever I try to enable the "normal surround sound" mode on the reciever, it's always much quieter than when I'm listing to it in Stereo or in DD5.1/DD4.0 like I get from DVD movies or from TV or from the PS2 when playing games that output DD4.0. I've heard that the Prologic II is suppose to be pretty good but I'm not seeing it, all it seems like to me it's doing is repeating it to the rear speakers and making the what ever I'm playing much quieter. Am I doing something wrong? I've tried watching VHS movies as well with this setting and I've found they're much less enjoyable than watching in stereo which is really quite sad.

Also I forgot to mention but when I use the PLII mode most of the sound is diverted to the center channel with the stereo and surround channels getting sound as well, except they're significantly quieter and it effectively makes using PLII sound like I'm listing to mono.

 

[wfooshee]

Pro Logic is not discrete channels, like 5.1. It's an encoding scheme that buries the center and surround in a normal stereo signal. When it goes through the decoder, the center and surround are extracted and sent to their speakers.

The encoding system is basically such that anyhting in both channels and identically phased is routed to the center channel. Anything in both channels and 180 degrees out of phase is routed to the surround. What's left is normal stereo.

There's no advantage to using the optical to carry this signal. It's not digital. Pro Logic is an analog stereo system, using phase tricks to carry more than 2 channels. It may actually sound better if you use the red and white audio cables into your receiver. I've never made the comparison, but I use the analog audio on my PS2.

The only time you would be required to use the optical cable is to get 5.1 from DVD movies. There are no games with digital audio, or 5.1 audio. In another thread, it was pointed out that a cut scene may have 5.1, but that's not gameplay, that's a DVD movie.

 

[imzjustplayin]

Pro Logic is not discrete channels, like 5.1. It's an encoding scheme that buries the center and surround in a normal stereo signal. When it goes through the decoder, the center and surround are extracted and sent to their speakers.

The encoding system is basically such that anyhting in both channels and identically phased is routed to the center channel. Anything in both channels and 180 degrees out of phase is routed to the surround. What's left is normal stereo.

There's no advantage to using the optical to carry this signal. It's not digital. Pro Logic is an analog stereo system, using phase tricks to carry more than 2 channels. It may actually sound better if you use the red and white audio cables into your receiver. I've never made the comparison, but I use the analog audio on my PS2.

The only time you would be required to use the optical cable is to get 5.1 from DVD movies. There are no games with digital audio, or 5.1 audio. In another thread, it was pointed out that a cut scene may have 5.1, but that's not gameplay, that's a DVD movie.

There are games with digital audio, such as GTA Vice city, though it only has 4.0 surround sound..

 

[Digital-Nitrate]

In addition, wfooshee is also mistaken on several aspects about Pro Logic.

Pro Logic is not discrete channels, like 5.1.

Actually it does offer four discrete channels if the original audio signal is an encoded matix signal.

There's no advantage to using the optical to carry this signal. It's not digital. Pro Logic is an analog stereo system, using phase tricks to carry more than 2 channels. It may actually sound better if you use the red and white audio cables into your receiver. I've never made the comparison, but I use the analog audio on my PS2.

This is not correct. While it is true that historically, Pro Logic was originally designed back in the 70's for theatrical film sound tracks, which of course were analog, the technology was not, and certainly is not limited to analog sound. All Pro Logic decoders have both analog and digital decoders.

More importantly, the audio from games on the PS2 are digitally encoded, and thus ideally you would not want to convert them to analog. So using the optical cable is ideal.

As far as comparisons between analog over RF cable and digital over optical cable, the important thing to remember is that you MUST calibrate your receiver/audio processor for each audio input. This is most likely the problem that the OP of this thread is experiencing. The simple solution of course is to turn the volume up when using the optical input.


BTW: For those wanting to get a better understanding of the various forms of Dolby Surround formats, like Pro Logic, PLII, PLIIx, Dolby Digital, DD+, Dolby TrueHD, and Dolby Digital Live among others, you may find the Wiki listing for Pro Logic a useful start. It has some decent explanations and comparisons, as well as many additional links for more thorough research and better understanding. 👍

 

[wfooshee]

Actually it does offer four discrete channels if the original audio signal is an encoded matix signal.

The encoded matrix is stored in a plain stereo signal. 2 channels. Yes, four channels are encoded, but it's a stereo track on the media. That's what I was saying. And those 2 channels can be digital, as on a Prologic CD (anybody have one of those? I have a couple.) or analog, as on the HiFi stereo VHS tapes with a Dolby Surround soundtrack. (Actually, Dolby Surround differs from Dolby Pro-logic in that there is no Center channel.)

Very similar to (for you old guys) some of the matrix-encoded Quadraphonic 4-channel systems back in the 70's.

More importantly, the audio from games on the PS2 are digitally encoded, and thus ideally you would not want to convert them to analog. So using the optical cable is ideal.

Of course the audio in the game is stored digitally, but it is my understanding that the optical feed from a game source in the PS2 is digitized from the console's analog audio output. In other words, the console does all the D-A conversion necessary to get the signals out to the TV, and the optical output is re-digitized from that audio signal. It's possible (nevah! ) that I am misinformed.

 

[Jedi2016]

One thing that affects the audio is how your receiver is decoding the signal. My receiver has two forced modes for PLII, Music and Movie. I read somewhere that game developers recommend the Movie setting (unless your receiver has a Game mode as well), but whenever I used it, the sound was very low and tinny, like nothing was being routed to the subwoofer, and a lot of the sound was (as the OP mentioned) forced more heavily into the center channel. All of these problems were alleviated when I switched it over to Music mode. Suddenly my subwoofer was in use again, and usage of the stereo and surround speakers increased significantly. Whatever the reason, it was that setting (contrary to developer recommendations) that seemed to deliver the "real" audio with proper depth and surround usage.