How many audio channels over 1 pin spdif ? (x-fi)

[skybu...@hotmail.com]

Hello,

Take a look at this picture, it shows pins for audigy and x-fi elite pro soundblasters:

http://pinouts.ru/visual/gen/sb_audigy2_ad_ext.jpg

ascii version in case picture is no longer available:

2 40
....................
....................
1 39

pins seem to be numbered vertically from bottom to top 1, 2, then next column is probably 3 4 and so forth.

Not sure which pins would be important to make a custom cable.

pin 5 spdif 0 in

pin 9 spdif 0 out
pin 27 spdif 3 out
pin 29 spdif 1 out
pin 31 spdif 2 out

Which other pins would be important ?

It mentions these SPDIF output pins. 0,1,2,3

So that's 4 pins.

How many audio channels can travel over 1 pin ?

Also how would these be connected into a cable, should gnd be included or another other pins

What I am trying to figure out if the X-Elite Pro soundblaster is what I currently believe it is:

7.1 Surround Sound Analog outputs
5.1 Surround Sound Digital outputs

However if only 4 spdif pins available then how would it achieve 6 channels for 5.1 surround sound digital ?

I read somewhat 1 spdif connection via normal connectors/cables can carry two audio channels.

So this ad_ext connector has 4 spdif pins, is the x-elite pro soundblaster perhaps a 7.1 digital output device after all ? But hampered/nerfed/capped by cable design ?

Currently I am investigating sound quality of laptop/hdmi digital vs dreampc2006/x-fi analog both to same receiver (denon 1909).

The digital connection from laptop is remarkable... it produces very high quality sound, sharper/more so than the x-fi analog signals.

So I am very interested in trying to connect the x-fi digitally.

I will most likely purchase spdif cables fiber optic and coax from a local shop if they have it and they probably do. I will purchase these mostly to see if there is indeed a big quality difference in audio signal between analog and digital from x-fi. I am starting to believe this is indeed the case.

So even testing x-fi 5.1 surround sound would be interesting to see quality differences.

Currently the laptop hdmi receiver setup is not producing surround sound correctly.

This is probably caused by the receiver being in 7ch stereo mode which is wrong.

This simply duplicates a stereo signal over multiple speakers which is wrong I believe.

For example the "rear right" signal can also be heard on the "right speaker" this is wrong, the "rear right" signal should only be heard on the "rear right speaker".

I think I know how to configure the receiver to select/set a different surround mode, it may have to be channel direct, or perhaps dolby digital ext/plus that sort of thing.

I will experiment with that tomorrow to see if correct surround sound can be produced from the laptop via hdmi to receiver.

This annoyed me when playing world of warships or company of heroes on the laptop... the direction of sound didn't seem right at all, so it was noticeable.

I must say the x-fi elite analog setup worked much simple straight out of the box into the receiver basically, so for noobies the analog setup is much easier to get working correctly.

Creative was smart to seperated the 8 channels into 4x2 stereo signals... the receiver I think sends this forth to the speakers. However this signal is probably not digital hence some signal loss from digital to analog convert and back to analog to digital convert dac/cad ;) :)

Today I spent many hours doing experiments and getting to know my receiver better and being able to configure it with just the 1 or 2 line display on the device itself instead of on screen display connected to monitor... cable probably too short anyway but I also wanted to learn to operate this device from itself without any other devices. I kinda like these technical challenges, guess it's my experience and age and mindset/determination to get it working, "failure is not an option" mindset from playing all that world of warships lol.

Also my x-fi elite pro came with this breakout box as I called it or as some call it official name now is i/o console. It also has spdifs... but only two spdifs out...

So are these the 4 pins from the ad_ext going to the breakout box ? forming two spdif outputs on it ?

What I also wonder about is the "flexi-jack" it can also be configured as an digital i/o.

Probably a spdif output.

It can work via RCA to mini cable or something like that.

So is this again the same 4 pins, perhaps 2 of them going /inout of that flexi jack ?

Or is this yet 2 additional spdif pins ?!?!?!?

So what is the actually ammount of spdif output pins/channels that this x-fi elite can do ?

Is it only 4 spdif pins output ?

Or is some whacky combination of:

ad_ext 4 spdif pins + digital i/o flexi jack possible ?

Perhaps resulting in a hardware/connection-wise output possibility of 6 spdifs outputs ?!?

Let's assume for a moment that this would be possible, would theoretically this be enough for 7.1 channels ? Or are 8 spdif pins neccessary for that ?

So this is where I am somewhat confused ?

Perhaps 3 signals can go over a 2 pin spdif output connector thanks to dolby/dts compression ? How does that work ? Same question as in beginning but kinda filling in the possible blanks here myself... which could be totally incorrect.

Bye for now,
Skybuck.