Sound Blaster x3 - dolby digital live issue

[gozer]

Good morning
This is my first topic here, so first I'd like to say something about me.
I'm not an audiophile, but just a videogamer from the '80, so I'm attached to some old technologies, like dolby digital.

Having the target of taking advantage of the dolby digital 5.1 and keep using my old receiver optical imput, I've purchased a Sound Blaster x3 and attached to my pc.
This way my pc can play my old dvds with 5.1 audio and the receiver reproduces the multy-channel audio, but something is going wrong.

Some audio effects from my test videos are completely missing!
As a counter-test I installed some old audio drivers (dolby4) in my pc, in order to make the spdif on my motherboard to output dolby digital, without using the X3, and the test videos plays perfectly, with all the effects I remember.

Is there something I am missing, or is the X3 a bad encoder for Dolby Digital?

Thanks a lot

 

[Dunring]

I've had that and remember setting it up like this:
Removed any other sound drivers and installed the SB suite which includes them all.
Set on Windows to 5.1 surround so it shows it as a Windows 5.1 device.
Also in command I did updates to the device twice which updates the program, but also the drivers need usually two updates.
There's an app I use DDU Display driver uninstalled, but it also cleans old sound drivers. Any conflicts can cause fits for the Creative stuff, so cleaning house is a safe bet.
Also try 48khz 24 bit mode. I think that's the limit for output on optical for that card or it's just in stereo, it might be as high as 9600hz, but I just run in 4800hz for gaming so never tried it.

 

[staticV3]

Hi @gozer! Welcome to ASR.

According to Creative, the X3 supports 7.1 surround sound output via Toslink, including Dolby Digital Live.

User error is definitely possible, but it's impossible to say for sure with the information provided.

 

[gozer]

Hi @gozer! Welcome to ASR.

According to Creative, the X3 supports 7.1 surround sound output via Toslink, including Dolby Digital Live.

User error is definitely possible, but it's impossible to say for sure with the information provided.

Thanks for the wellcome.
User error is possible of course, so maybe is there a way to test this X3 rather than the SoundBlaster software itself or the following video I used:
video test
Is there any software/audio test I can use to see if the sound card is working properly in 5.1?
Thanks

 

[staticV3]

Is there any software/audio test I can use to see if the sound card is working properly in 5.1?

There's a sound test built into Windows' Sound Control Panel.

Beyond that, try installing the Sound Blaster Command software.

Lastly, to send DD Live audio to your AVR, the program that's sending the audio must support bitstream.

Without bitstream, the X3 will output regular LPCM instead, which could explain the missing effects.

 

[gozer]

I see from the specs that the X3 outputs like the following:
Playback Resolution (Stereo): PCM 16/24/32-bit / 48.0, 96.0, 192.0 kHz
Risoluzione riproduzione (Uscita ottica): PCM 16/24-bit / 48.0, 96.0, 192.0 kHz
Surround 7.1: PCM 16/24/32-bit / 48.0, 96.0, 192.0 kHz
Dolby Digital Live: 16-bit, 48.0 kHz

So I guess it is PCM.
Why the pcm lacks effects compared to bitstream?

 

[staticV3]

Why the pcm lacks effects compared to bitstream?

Toslink has limited bandwidth.

LPCM is uncompressed audio, and so 2.0 is the limit there.

Toslink can only send multichannel audio in compressed/encoded format. That's called bitstream.

 

[gozer]

I finally found the issue source!
I noticed that all the test video files with missing effects had two tracks, one using various codecs, like Mpeg4, Mp3 or others, and another track that was always AC3!
So I believed that it could have been the AC3 codec used by VLC player that was bad... and in fact I tried Windows Media Player Classic and all the test files now sound perfectly without any missing effect.

The mistery remaining is why on the same pc, if I plug off the Sound Blaster X3 and I use the motherboard optical output, with Dolby Home Theater V4 driver (on Realtek hd audio chipset) VLC is able to reproduce those effects without any issue...
Maybe the Dolby Home Theater driver has its own AC3 codec?