Malik wrote:

Or will we get the same 3D positional experience?

I don't think so. Isn't Aureal Vortek 2 positional audio is outputted through discreet analog channels? Ie. front L/R and rear L/R? I think you'll lose the 3D positional experience if you're only using two channels --let alone passing it through another soundcard.

That, by the way, is also my biggest question: how to pass Aureal Vortex 2 positional audio through a 5.1 preamplifier? A typical 5.1 preamp has 5.1 analog input, while a Vortex 2 sound card has 4.0 analog output. Thus, the preamp's center input and sub input will be "empty", which means the subwoofer and the center speaker won't sound.

Is there any 4.0 to 5.1 converter? Or how practical it is for a DIY project?

Disclaimer: I've never tried A3D positional audio with only two channels. My only A3D soundcard is Turtle Beach Montego Quadzilla, which has four channel output (4.0). I was using the sound card with a four channel Altec Lansing speaker set.

Kreshna Aryaguna Nurzaman wrote:

I've never tried A3D positional audio with only two channels.

Its very good with headphones

Davros wrote:

Kreshna Aryaguna Nurzaman wrote:

I've never tried A3D positional audio with only two channels.

Its very good with headphones

Hmm... Will such 3D audio be maintained when bypassed through secondary sound card like Malik mentioned above?

Kreshna Aryaguna Nurzaman wrote:

Is there any 4.0 to 5.1 converter? Or how practical it is for a DIY project?

IMHO, I believe the a 4.0 sound will best be heard with a 4-speaker configuration, if left alone. For upmixing, any good decoder/receiver/mixer will do.

For example, all my sounds from both my main system and my classic system go to my Marantz SR5002 A/V receiver that I'm using. Any analog sounds can be upmixed to Dolby ProLogic II configuration. This means, like hearing Dos' Wing Commander IV's Dolby Surround effects in the movies which will be automatically sourced out to the proper channels via the receiver, even when conected via the ordinary 1-2 stereo audio cable.

A picture of the receiver I'm having :

When in windows, there's the option of sending pure digital signal via the X-Fi's I/O Drive Panel and the Audigy's I/O Drive. My Windows 98/ME/W2K use the Audigy's I/O Panel to output digital signals. The SR5002 will decode any Dolby PLII or Digital bitstream when detected, if the receiver is
set to auto. Games like Diablo II will heard in Dolby Surround while playing the movies.

The Dos machine is connected to the receiver via the AWE32's Line-Out.

A good receiver should play the respective 4.0/4.1 sound source at the proper channel when no upmixing is selected. I haven't tried a 4 channel game though.

Coming back to the Vortex engine, I wonder if the quality of the 3D positional audio, especially the 3D positional audio from a 2-speaker system will be distorted when passing through another card. Reason I'm asking is if it's possible to maintain the same quality without constantly changing the limited speaker connection to and fro.

Connecting a 2-channel oriented enhanced sound to the surround receiver will definitely produce "over-enhanced" effects, which is not desirable. This will give a false sense of positioning.

Malik wrote:

Kreshna Aryaguna Nurzaman wrote:

Is there any 4.0 to 5.1 converter? Or how practical it is for a DIY project?

IMHO, I believe the a 4.0 sound will best be heard with a 4-speaker configuration, if left alone. For upmixing, any good decoder/receiver/mixer will do.

Hope you don't mean more questions then. I'm still a newbie in stereo system. Some years ago my dad taught me some things about stereo (he was an audiophile himself --and quite a snobbish one! Miss you dad), but it was long before stuff like S/PDIF and Dolby ProLogic.

About Dolby ProLogic

Malik wrote:

When in windows, there's the option of sending pure digital signal via the X-Fi's I/O Drive Panel and the Audigy's I/O Drive. My Windows 98/ME/W2K use the Audigy's I/O Panel to output digital signals. The SR5002 will decode any Dolby PLII or Digital bitstream when detected, if the receiver isset to auto. Games like Diablo II will heard in Dolby Surround while playing the movies.

Thus, SR5002 can decode Dolby PLII surround signal that comes from S/PDIF channel. Can every receiver do that? Or what spec parameters should I pay attention to, to ensure that the receiver can decode PLII signal from S/PDIF?

Furthermore, can every S/PDIF capable sound card send Dolby PLII surround signal through S/PDIF? I guess I have to use analog 2.0 (plain stereo) to send PLII surround signal for cards like AWE32, because IIRC it doesn't have S/PDIF output capability. But how about sound cards like Diamond MX300?

About 4.0 to 5.1

Malik wrote:

A good receiver should play the respective 4.0/4.1 sound source at the proper channel when no upmixing is selected

But if upmixing is disabled, then only four of your speakers will sound, won't them? The center and the sub won't sound at all, isn't it?

Can the receiver upmix 4.0 to 5.1, thus, enabling all speakers to sound, without severely distorting the sense of positioning?

About 2.0 to 5.1

Malik wrote:

Connecting a 2-channel oriented enhanced sound to the surround receiver will definitely produce "over-enhanced" effects, which is not desirable. This will give a false sense of positioning.

I think you can disable upmixing to get a correct sense of positioning, although you'll only hear it from two speakers (front left and front right).

I believe a sound card which was designed or is capable to send out digital signal, will have, at least, an add-on board or connector to do this.

If the sound card is able to transmit a digital audio signal, even if the sound card does not have the ability to decode any dolby surround format, and if it can do this without altering or degrading the audio signal, the capable decoder-receiver at the receiving end will handle the rest.

The type of decoders available in a particular unit will be explicitly mentioned in the manual and usually printed or labelled or embossed on the receiver's casing. Only those decoders which support PLII Decoding can decode the PLII and so on.

Some units, like the SR5002, can decode multiple formats - Dolby DTS, Dolby Digital, 5.1, 7.1, SRS, Virtal Surround, etc.

A digital bitstream, which is transmitted via the co-axial or the optical cable, will be decoded automatically to the respective format when the receiver is set to "AUTO". When playing a DVD, depending on the type of sound selected in the audio menu on the dvd, the said format will be played. I use Intervideo WinDVD 8 which transmit the audio digitally via the X-Fi to the receiver. X-Fi itself is able to decode 7.1 channels but I usually bypass the X-Fi, so that the digital audio gets decoded only at the receiver.

As you can see from the picture, there is a separate 7.1 channel section at the top left of the back panel. I connect the X-Fi's audio out using the back of the card to send signals directly to the respective 7.1 channels directly. For modern gaming, I use this mode (7.1 CH).

I use the X-Fi's I/O drive to send the digital audio to the receiver while watching movies. Again, depending on the type of Audio selected at the DVD Audio menu, you get the same quality here too - DTS or Digital or a simple 5.1.

The I/O Drive is also used for transmitting MIDI data to the MT-32 from within dosbox for playing dos games, even in Windows 7, as in my previous post.

My PS3 is connected to the receiver via optical and gives a DTS gaming experience. The PS2 gives Pro Logic II Experience (also via Optical) and even my PSOne, which is connected via the ordinary 2 channel audio cable can be upmixed to play the Dolby Surround sound like in Need for Speed III. Even the PSOne's FIFA games will give out true stadium experience - the crowd sounds over the surround speakers.

Generally, a good receiver's UPMIXING capability is jaw dropping. By this, I mean if you want to experience true Surround with Dos games, it's possible with just an ordinary audio out stereo L/R cable.

Any good sound card, including the MX300 will perform well.

Upmixing, takes the normal stereo analog source and "upmix" it to a surround format - most commonly the newer Dolby ProLogic II Ex format. I believe any good card will do with a good receiver.

If the game, even an old dos game, supports Dolby Surround (Wing Commander IV comes to mind), the result is just that - Dolby Surround, even if the signal is NOT sent over a digital line. I'm not sure if an anolog signal can be decoded but the result is truly amazing.

(I wonder if this is the way companies like Origin had in mind when they released the Dolby Surround format in the Wing Commander IV for Dos game - remember the Train Dolby runner? - I can't think of any other way for a dos game to transmit digital sound via a digital capable cable - coaxial or optical).

The problem comes when playing a 4 channel and 2 channel POSITIONING gaming - more so with 2 channel gaming with upmixing.
Upmixing will spoil the expereince if listening to sound effects which simulate the hind semi circle range i.e. from +90° to +270° range.

The problem with 4 channel gaming without a discrete 4 speaker system, or at least in my case, is that, there's no option to choose a 4 channel upmixing. If I disable upmixing, it goes to stereo - only 2 channels. If upmixing is enabled, it goes to ProLogic II (5.1) or Pro Logic II Ex (7.1) mode (selectable). My speakers are connected in a 7.1 configuration. For 5.1 upmixing, the side left and side right speakers will be ignored. So the front right or front left will have small mix-up with the centre channel in 5.1 mode. The 7.1 mode will have a small mix-up at the side lfet/right level when playing the rear right/left sounds.

These games - especially with Aureal3D Vortex 1 is best heard with an ordinary 2 speaker setup - because it was developed with 2 speaker setup in mind, at least, the Vortex 1. I believe till date, Aureal3D is the best 3D audio positioning system with ordinary 2 speaker set.

Kreshna Aryaguna Nurzaman wrote:

I think you can disable upmixing to get a correct sense of positioning, although you'll only hear it from two speakers (front left and front right).

Yes, you're right. 😀

Edit : If a sound card allows digital sound to pass through it, it can send any format - Dolby ProLogic/ProLogicII/DTS/Digital/etc. The card does not need to worry about what format it is transmitting, as long as it is transmitting a "digital" audio signal, in which one Dolby type or another is encoded within it.

A3D works by far the best with 2 speaker output (maybe headphones too). If you look up reviews you can see reviewers say that Live! actually does quadraphonic output better.

Malik wrote:

The problem with 4 channel gaming without a discrete 4 speaker system, or at least in my case, is that, there's no option to choose a 4 channel upmixing. If I disable upmixing, it goes to stereo - only 2 channels.

Pardon for being nitpicky, but....

If you disable upmixing, I believe you will still get 4 channel surround by connecting the Diamond MX300 4.0 analog outputs to your receiver's 7.1 analog inputs. You see, like shown in the diagram below:

1sound card (4.0)           receiver (7.1)
2----------------           ------------
3
4(no output) ----------->    C
5
6L           ----------->    L
7
8R           ----------->    R
9
10SL          ----------->    SL
11
12SR          ----------->    SR
13
14(no output) ----------->    SBL
15
16(no output) ----------->    SBR
17
18(no output) ----------->    SW

Problem is: only four of your 7.1 speakers will produce sound: L, R, SL, and LR. The C (center speakers) will be muted, and so will the SBL, SBR, C (center), and SW (subwoofer).

Or alternatively, you can connect the Diamond MX300 4.0 analog outputs to the L, R, SBL, and SBR inputs on your receiver. The SL and SR will be muted, and the subwoofer will still be muted.

See, this is the problem that plagued my mind for months. Aureal 3D 2.0 sound cards typically has 4.0 output: L, R, SL, and SR. There is no SBL, no SBR, no C (Center), and no SW either.

The problem is: how to connect the sound cards 4.0 analog output to a receiver's 7.1 input without losing any sound from the speakers. In order to achieve that, I think we need a 4.0 to 7.1 "audio converter" that can do the following things simultaneously:

(1) First, each L and R channel needs to be split and then mixed to produce center signal.

1"split and mix"
2
3sound card (4.0)           receiver (7.1)
4----------------           ------------
5
6L           ----------->    L
7                |
8                |
9                ------->    C
10                |
11                |
12R           ----------->    R

(2) Then, each of the SL and SR channel on the sound card needs to be split to produce SBL and SBR signal.

1"splitting the surround channels"
2
3sound card (4.0)           receiver (7.1)
4----------------           ------------
5
6SL          ----------->   SL
7                |
8                |
9                ------->   SBL
10
11
12SR          ----------->   SR
13                |
14                |
15                ------->   SBR

Note that this step will not produce magic. In other words, the SBR speakers will produce exactly the same sound as the SR speakers. Also, this solution will arguably "distort" the position of the 3D sound, because what was originally emitted from two surround speakers, is now emitted from four surround speakers. However, there are lunatics like me who want to hear the sound from all speakers at all cost.

(3) Finally, the low frequency part of each channel (L, R, SL, SR) should be split to produce input for the receiver's SW channel. This configuration is probably too complex to be drawn with ASCII text, so I left it blank.

Question is: does such 4.0 to 7.1 "audio converter" ever exist? And how difficult it is to build one in a DIY project? I have a friend whose hobby is creating DIY electronic circuits, by the way.

PS: and yes, I'm obsessive-compulsive over this "4.0 to 7.1" thing as well. 😉

Alright, this is simpler than it looks.

Yes, you're right. To get a true 4.0 support with this receiver is easy. Just connect the respective output from the MX300 to the 7.1 CH Input. Yes, the centre, side L &R will not work then. This will only work with receivers that have a discrete 4.0/5.1/6.1 or 7.1 channel INPUTS.

It's difficult to convert a 4.0 signal to a 7.1 channel setup, since the 4 speaker setup is absolute.

The "audio converter" is currently available as Dolby ProLogic II EX and Matrix for 7.1 channel Upmixing, and Dolby Pro Logic I or II with or without Ex for 5.1 Upmixing, which are in-built with certain receivers, like this SR5002.

Upmixing helps anything from an ordinary stereo L&R input to be "upmixed" to a 5.1 or 7.1 channel setup.

And believe me, this ordinary stereo to Dolby Surround upmixing is convincingly good. Even more so when the dos game supports Dolby Surround.

I leave the 7.1 channel setup with my more modern WinXP/Vista/7 system because the X-Fi gobbles up the whole 7.1 channel section.

As you can see, the receiver supports 6 more stereo L&R inputs, 5 digital inputs (- 2 co-axial and 3 optical).

One of my classic pc's awe32 connects to one of the stereo inputs, my PSone to another, PS2 to one of the optical, PS3 to another optical, the Cable TV's audio to another stereo input, the Roland SC-55 to another stereo input, LAPC-I to another input.....etc.

Malik wrote:

Upmixing helps anything from an ordinary stereo L&R input to be "upmixed" to a 5.1 or 7.1 channel setup.

And believe me, this ordinary stereo to Dolby Surround upmixing is convincingly good. Even more so when the dos game supports Dolby Surround.

Yup. Imagine playing Star Control II with Dolby Surround upmixing.

Malik wrote:

I leave the 7.1 channel setup with my more modern WinXP/Vista/7 system because the X-Fi gobbles up the whole 7.1 channel section.

I wonder if there's a 7.1 version of this thing. Its audio switch is only 2.0 stereo.

Anyway, back to the topic, yes, I start wondering too if passing two-speakers Aureal 3D signal through another sound card will ruin the positional quality. I think if the sound card doesn't do upmixing, it should the positional audio should be maintained, but I'm still not sure.

Aureal's two-speakers positional audio uses HRTF, doesn't it? How does HRTF positional audio signal is sent through plain stereo channel? Is it matrix-encoded like Dolby Surround?

As far as I can tell, HRTF may not be matrix encoded. More like differentiation in frequencies within a constant block.