PDA

View Full Version : Nforce 3\4 dolby pro logic output?


CaptNKILL
10-25-04, 01:42 AM
Im really sorry for a double post, but I think this deserves its own thread if I can get an answer:
With an nForce 3 board, do you guys use the normal sound drivers\nvmixer? Or do you have to use realtek ones? If you use the nvidia drivers\nvmixer, please list the outputs that you have available on the tab where you select "2 speakers", "4 speakers" etc..

This is really important because as of right now, I know the ALC850 (or whatever realtek chip these boards have) doesnt do Dolby DIGITAL encoding. BUT, Im having trouble finding any information about Dolby Pro Logic encoding (which is done through a single analog jack, but gives you 4 channel output). My Soundstorm supports this, in the output selection box its labeled "4 speakers (dolby surround)" and when I select it I get a Dolby Surround - Pro Logic logo at the bottom left corner of the window.

If you guys can test this I'll really really really really appreciate it. This applies to anyone with an nForce 3 chipset motherboard.

BTW, its so important because with my system (along with many many others) theres no way to get surround sound without Dolby Pro Logic output.

Also, I guess anyone with a realtek chip onboard or any other kind of integrated sound should CHECK THEIR OUTPUT OPTIONS. I have seen almost NOTHING about the Nforce 2's dolby pro logic output (because pro logic 1 is pretty old tech, so no one talks about it, yet many still need it) so it seems very possible that some sound solutions may have this capability without anyone knowing it.

mezkal
10-25-04, 01:51 AM
OK. Just so you know - Pro Logic is essentially just a stereo signal with hz variance (and cross-overs) differentiating between the front centre ( mid range) Left and Rights (mid range and some high end mixed with a portion of the lower end) and Surrounds (high end, mono with stereo reverb effects).

Any stereo output soundcard can process and deliver a Pro Logic signal.

Pro Logic II is another matter. Pro Logic II is dolby digital over Pro Logic circuitry. That is entirely dependent on the host for processing. Ie your sound card needs to support Pro Logic II.

superbooga
10-25-04, 08:44 AM
OK. Just so you know - Pro Logic is essentially just a stereo signal with hz variance (and cross-overs) differentiating between the front centre ( mid range) Left and Rights (mid range and some high end mixed with a portion of the lower end) and Surrounds (high end, mono with stereo reverb effects).

Any stereo output soundcard can process and deliver a Pro Logic signal.

Pro Logic II is another matter. Pro Logic II is dolby digital over Pro Logic circuitry. That is entirely dependent on the host for processing. Ie your sound card needs to support Pro Logic II.

Pro Logic II isn't DD over Pro Logic circuitry. It's still a stereo signal, but better sound quality overall. The surround is in stereo now, plus it's frequency response is no longer limited to 8kHz.

Pro Logic and PLII are both "active" decoders, multi-channel sound can be derived from a stereo signal, regardless of if the signal has gone through matrix encoding. What you referred to in the first paragraph is really Dolby Surround, which predates Pro Logic. Pro Logic can be seen as an extension of Dolby Surround. Dolby Surround only produced the surround channel with special encoding, but PL and PLII can produce the surround channel without going through the encoding process. Of course, results will probably be better with encoding.

In any case, any game that has "Dolby Surround" on it usually means the audio has undergone through some sort of matrix encoding. The output is STILL stereo, but if you hook it up to a Dolby Surround/PL/PLII capable decoder, the results will be quite good. Obviously discrete multi-channel audio will still be better.

superbooga
10-25-04, 08:47 AM
Another thing, there is a new format called Dolby Pro Logic IIx. Basically it's capable of doing matrix decoding on 5.1 Dolby Digital signals.

Pro Logic IIx replaces Dolby Digital EX (a.k.a THX-EX processing). DD-EX produced an extra mono rear channel. PLIIx turns this rear channel into stereo.

CaptNKILL
10-25-04, 03:32 PM
OK. Just so you know - Pro Logic is essentially just a stereo signal with hz variance (and cross-overs) differentiating between the front centre ( mid range) Left and Rights (mid range and some high end mixed with a portion of the lower end) and Surrounds (high end, mono with stereo reverb effects).

Any stereo output soundcard can process and deliver a Pro Logic signal.

Pro Logic II is another matter. Pro Logic II is dolby digital over Pro Logic circuitry. That is entirely dependent on the host for processing. Ie your sound card needs to support Pro Logic II.
Well no sound card ive ever used could output Dolby Pro Logic. Only soundstorm.

I realize its just emulation, but I get surround sound and it works well (i can tell when something is behind me in a game because it comes from my rear speakers) so to me its 10x better than just normal stereo. Ive tried getting dolby pro logic from my Sound Blaster Live! 5.1, my Turtle Beach Santa Cruz and another integrated audio chip, none of them gave options for this.

I dont get surround in normal 2 speaker modes, it has to be dolby pro logic encoded or it doesnt work.

EDIT: And id rather not turn this into an audio discussion about what is better. I cant afford another $300 sound system right now, and all my current system supports is stereo or Dolby Pro Logic Surround. Im looking forward to upgrading my motherboard and CPU, so I want to know if I'll be able to get surround sound from an nForce 3 with my current system.

CaptNKILL
10-26-04, 01:21 AM
:|

Ok, so apparently no one has both an Nforce 3 board and 15 seconds to spare...

CaptNKILL
10-26-04, 11:30 PM
Wow this place is just bursting with activity...

:lame:

|JuiceZ|
10-28-04, 10:44 AM
...Im looking forward to upgrading my motherboard and CPU, so I want to know if I'll be able to get surround sound from an nForce 3 with my current system.

Yes, using either the Realtek or Nvidia audio drivers, you can get 5.1/7.1 surround sound from the ALC850 chipset via analog (music/games/movies) or coax digital (DD/DTS encoded movie) connection.

CaptNKILL
10-28-04, 06:00 PM
Yes, using either the Realtek or Nvidia audio drivers, you can get 5.1/7.1 surround sound from the ALC850 chipset via analog (music/games/movies) or coax digital (DD/DTS encoded movie) connection.
But does surround work through a single analog jack?

|JuiceZ|
10-28-04, 08:36 PM
But does surround work through a single analog jack?

No. A single analog line is not capable of splitting sound into multiple channels, only coax or optical digital connection are able to do that. To get surround through analog, a special cable is used with multiple plugs on either end for Front L/R, Rear L/R & Center/Sub that are usually supplied w/ the speakers.

CaptNKILL
10-28-04, 08:44 PM
No. A single analog line is not capable of splitting sound into multiple channels, only coax or optical digital connection are able to do that. To get surround through analog, a special cable is used with multiple plugs on either end for Front L/R, Rear L/R & Center/Sub that are usually supplied w/ the speakers.
Thats what the whole thread was about :p

Dolby Pro Logic sends a surround signal through a single jack. Im using a single jack right now and i get surround sound, im wondering if the ALC850 can do this too.

|JuiceZ|
10-28-04, 09:00 PM
Thats what the whole thread was about :p

Dolby Pro Logic sends a surround signal through a single jack. Im using a single jack right now and i get surround sound, im wondering if the ALC850 can do this too.

But its not because its Dolby Pro Logic, its because you're mb is equipped with Soundstorm which is able to actively encode all audio into dolby digital 5.1 using a digital connection to your speakers. Its currently the only pc audio device on the market capable of doing that right now, thats why everyone is upset it didn't find its way to NF4 series mbs.

The way you worded your question was kind of confusing, prolly why it didn't get a lot of replies ;)

CaptNKILL
10-28-04, 09:48 PM
But its not because its Dolby Pro Logic, its because you're mb is equipped with Soundstorm which is able to actively encode all audio into dolby digital 5.1 using a digital connection to your speakers. Its currently the only pc audio device on the market capable of doing that right now, thats why everyone is upset it didn't find its way to NF4 series mbs.

The way you worded your question was kind of confusing, prolly why it didn't get a lot of replies ;)
No no, its encoding dolby pro logic through an analog connection. I guess ill have to take a screen shot of it in the nvmixer setting.

I dont have a digital reciever so I know it isnt dolby digital encoding (it is from 1994, dolby pro logic surround was the analog standard then). My reciever only has 2 RCA jacks (left&right) for input and I have a y-cable going from them to a single mini-jack. That is plugged into my front speaker port on my soundstorm. In the nvmixer i dont get surround sound with my reciever unless I select the "4 speakers (dolby surround)" setting which enabled Dolby Pro Logic encoding (which is an analog signal, not digital) through a single analog connector. I know it does this because when I set it to "4 speakers (dolby surround)", a little logo appears. Its the "Dolby Pro Logic Surround" logo... the same one on my reciever.

I guess the reason no one posted was because Pro Logic isnt something everyone knows about. I dont blame anyone for being confused, its kind of odd to get a surround signal from a single analog jack (it had me puzzled too), but this is how it works.

All I made this thread for was to have someone with a newer board (such as an nforce 3 with an ALC850) see if they had a similar option to the one in nvmixer that enables Dolby Pro Logic surround encoding on my system.

EDIT:
Here is the nvmixer setting that gives me surround (NO OTHER SETTING DOES).
http://www.nvnews.net/vbulletin/attachment.php?attachmentid=8435&stc=1

EDIT2: here is how dolby pro logic works for those that dont know...
http://www.dolby.com/professional/pro_audio_engineering/solutions_surround.html

superbooga
10-29-04, 05:37 AM
Okay, CaptNKILL:

The thing is, from a physical/connectivity standpoint, there is ZERO difference between analog stereo and Pro Logic.

The important thing is: Can you force your receiver to do Pro Logic decoding, on signals that are not Pro-Logic processed? Most receivers nowadays can, they can do 2 channel to 5 channel expansion using a variety of techniques (Dolby 3-channel surround, Pro Logic, Pro Logic II, DTS Neo, CMSS, Logic 7, etc.)

It's important to note that Pro Logic is still only TWO discrete audio channels. Rating from "worst surround effect" to "best surround effect" goes:

1) Stereo
2) Stereo + Pro Logic decoding
3) Stereo + Pro Logic encoding + Pro Logic decoding
4) Discrete 5.1 channel (Dolby Digital)

So the point is, you SHOULD BE able to get surround sound, even from non-Pro Logic signals, IF you can force your receiver into Pro Logic mode.

If you lose the Soundstorm, you will lose the Pro Logic encoding. There MIGHT BE a software solution or something of that sort, that can encode Pro Logic into stereo. I know AC3Filter can, but I think AC3Filter is only for movie playback?

CaptNKILL
10-29-04, 01:48 PM
Thanks for the post.

It doesnt look like I can force dolby surround for 2 channels. I only have a few buttons on here for different modes.
Dolby Pro Logic, Dolby 3 Stereo, Bypass, Line Straight

I know someones going to chime in with something insightful like "your reciever sucks, its time for an upgrade" but I know that already :retard:. I just dont want to buy a new one until after the rest of my computer is ready for the new games that are coming out soon... plus, just I cant afford it. Like I said, it works great with soundstorm, I just wanted someone with an ALC850 (or anything else!) to see if they have an option like this.

I guess I can keep playing with it, but I really dont think I have an option to "force" dolby pro logic.

CaptNKILL
10-29-04, 02:24 PM
Well I just checked everything I possibly could and nothing gets me surround sound except when I use the "Dolby Surround" mode in nvmixer.

Some times there is some very very very low volume sound coming from the rears (I have to almost put my ear on the speaker). But its just a very very low volume copy of the front speakers, it isnt actually a sound that should be coming from the rears.

I did my testing by enabling EAX in Team Fortress Classic (fastest loading game i have, and with eax on, I get surround sound) and going into the game and tossing a grenade. Then I turn around 180 degrees and if the explosion actually plays through the rear speakers, then I have surround sound. Only "dolby surround" mode gave me this.

I checked the manual for my reciever too and it says that on this reciever, Dolby Pro Logic requires a Dolby Pro Logic encoded signal. And they showed the logo that a pro logic source will have on it, and its the same one that is in nvmixer.

EDIT: Btw, are you 100% sure that no other sound solution can encode dolby pro logic? I havent seen it mentioned in any Soundstorm documentation... only in the nvmixer. So I assumed (by creating this thread) the only way to check was to have someone check their nvmixer\sound control panel options.

|JuiceZ|
10-29-04, 03:18 PM
EDIT: Btw, are you 100% sure that no other sound solution can encode dolby pro logic? I havent seen it mentioned in any Soundstorm documentation... only in the nvmixer. So I assumed (by creating this thread) the only way to check was to have someone check their nvmixer\sound control panel options.

I think you're still a bit confused, either that or you've got a weird receiver. What model is it?

It's important to note that Pro Logic is still only TWO discrete audio channels.

You keep referring to Dolby Pro Logic as the "surround sound" when in fact as superbooga stated, Dolby Pro Logic only outputs audio to two discret channels (stereo). My parents have an old receiver as well and their's works the same way.

The important thing is: Can you force your receiver to do Pro Logic decoding, on signals that are not Pro-Logic processed? Most receivers nowadays can, they can do 2 channel to 5 channel expansion using a variety of techniques (Dolby 3-channel surround, Pro Logic, Pro Logic II, DTS Neo, CMSS, Logic 7, etc.)

In other words, if you're in fact getting multi-directional surround sound from all your speakers in "Pro Logic" mode, its because your receiver is actively doing a 2 to 5 channel upmix of some sort.

From personal experience, the only way I could get "non-directional" surround sound from the Z680's/Z5500's in Pro Logic mode using ALC850, was by switching to Stereo X2 setting on the speakers which basically just duplicates the output going to the two front left/right satellites into rear left/right sats. This setting was only used for listening to mp3's though since most music unless its DVD-Audio (5.1) are only encoded into two-channels (stereo). When playing games, I'd would switch to 6-channel analog setting on the speakers to get "multi-directional" surround sound. That's basically what you want when playing games specifically fps so you can hear which direction enemies are coming from. Unless you're using soundstorm, the general consenses for best sq is analog for music & games, digital for movies.

CaptNKILL
10-29-04, 04:06 PM
Well, I dont really know what to say. Im not confused, because ive been using this reciever with my soundstorm (and ive tried other sound cards) for over year and I know how it works.

My recieer is a KENWOOD KR-V5570, my brother just told me that he purchased it in 1995-1996.

I cant really say any more that I havent already said. I get 2 front channels and one rear channel, just like Dolby Pro Logic Surround is supposed to have. I only get it when I enable dolby surround in nvmixer.

Since none of us really know exactly whats going on, then isnt it safe to assume that its working exactly as it says in the manual for my reciever? Im getting a Dolby Pro Logic Surround encoded analog signal which my reciever decodes into front l\r and rear surround channels. For what its worth, my rear channels arent as clear as my fronts, so yes, there is probably some sort of compression.

I wish you guys could be here to hear this thing so you know exactly what its doing. I dont see how it could possibly be upmixing anything because in nvmixer i have control over my front l\r AND rear output volumes. I can lower the front speaker volumes independantly from the rears through nvmixer. In fact, i run my fronts at half volume so i can hear my rears more clearly. In any sound mode other than "4 speakers (dolby surround)" the rear volume adjustments dont adjust the rears.

EDIT:
Here is the .pdf version of my manual:
ftp://docs.kenwoodusa.com/manuals/OM-KR-V5570-1995-KUSA.pdf

EDIT2: I dont mean to confuse things any more but I also get a center channel, but it isnt discrete, its just a blend of the left and rights. My sub is spliced with my center speaker.

Cota
10-29-04, 07:18 PM
most digital receivers will turn any ordinary stereo source into sort of 5.1 by default. Its not real 5.1 as it only takes the front channel signal and passes it to the surround speakers.

CaptNKILL
10-29-04, 08:03 PM
most digital receivers will turn any ordinary stereo source into sort of 5.1 by default. Its not real 5.1 as it only takes the front channel signal and passes it to the surround speakers.
Ugh... its not a digital reciever. It isnt 5.1. It isnt copying the channels. :banghead:

superbooga
11-01-04, 04:33 AM
most digital receivers will turn any ordinary stereo source into sort of 5.1 by default. Its not real 5.1 as it only takes the front channel signal and passes it to the surround speakers.

This mode is usually called 4-channel or 5-channel stereo. Basically mirrors the sound from the front to the back.

Pro Logic (and similar methods such as Pro Logic II, and Logic 7), however IS NOT this. It is far more advanced than just a simple mirror. Phase and frequency shifts are carefully analyzed, and the complete surround field is recreated from just two channels.

If you have a left and right channel that is out-of-phase, it usually sounds very "open", without a central point. A Pro Logic decoder will then divide this signal, part of it going to the rear channels. On the other hand, signals that are in phase have a very distinguishable central point. In that case, the decoder will use the left/right + center speaker to create this point. With Pro Logic II, the size of the center speaker field and other parameters can be adjusted.

Even without actual encoding the signals in, the best methods with the best algorithms (Pro Logic II and Logic 7) can do an really really good job, in fact, in some cases it's almost as good as discrete 5.1.

superbooga
11-01-04, 04:40 AM
JuiceZ:

By definition, Pro Logic is surround sound. Although I usually prefer using stereo for music listening, there are many, many people who enjoy using Pro Logic processing on 2 channel sources.

Look, many receivers are 7.1 now. However, there is NO discrete 7-channel audio standard, at least for use in homes. How do they get 7 channels? Matrix decoding of course. Pro-logic is the same concept.

In addition to matrix decoding, there is also matrix encoding. Now most receivers can do matrix decoding without the presence of matrix encoding, but matrix encoding generally yields better results. CaptNKILL's problem is his receiver cannot do matrix decoding w/o matrix encoding. The Soundstorm can do matrix encoding. He's looking for another solution that can.

superbooga
11-01-04, 04:43 AM
Another thing, games and movies that have Dolby Surround or Dolby Pro Logic logo on them usually mean they have matrix encoded content within the stereo signal. For games, it means the encoding is done in software.

I know Diablo II and Warcraft III supposedly have Dolby Surround, maybe that means a receiver will auto-detect and switch to Pro Logic with these two games.

CaptNKILL
11-01-04, 01:11 PM
In addition to matrix decoding, there is also matrix encoding. Now most receivers can do matrix decoding without the presence of matrix encoding, but matrix encoding generally yields better results. CaptNKILL's problem is his receiver cannot do matrix decoding w/o matrix encoding. The Soundstorm can do matrix encoding. He's looking for another solution that can.
Thank you :D

And like I said before, anyone can search all over and find practically nothing about the "matrix encoding" or "dolby pro logic" support for Soundstorm. So I was hoping that other solutions supported it as well, but just didnt mention it in any documentation. So its very possible that the ALC850 (or pretty much any other sound chip\card) could have this ability without anyone even knowing. Thats why I made this thread to ask people to check their sound settings\nvmixer for an option similar to this one :rolleyes: