Creative Sound Blaster ZxR Optical s/pDIF Surround Recording

I’m recording my xbox 360 game play sound and possibly some OTA Antenna receiver Dolby 5.1 Surround through a Toslink optical cable input on the daughter card of the SB ZxR sound card.

I’m using an Intel Core i7 2600 in an Asus p8p67 deluxe running Windows 7 Ultimate x64 using the Creative Labs Sound Blaster ZxR.

It works fine for Xbox 360 dashboard System Settings, Console, Digital Audio, set to Stereo (2 channel sound), but does not when xb360 is set for Dolby Digital 5.1 output since the Audacity drop down list box for the recording device has only the options for Stereo or Mono–even when 5.1 Surround is being output by the xb360.

When the incoming audio stream of 5.1 surround is recorded by audacity, the sampled sound is a huge amount of loud almost white noise of random digital static sound.

What audio device capabilities enumeration is being used to determine if incoming AC3 multichannel digital optical signals are more than stereo since this stream could, in theory, change on the fly depending on the program material being sent by the source device?

Is this the fault of the sound card driver from Creative Labs and is being reported improperly to MS Windows intermediate level device driver layers, that are in turn reported to audacity in its enumeration of the device’s input stream contents?

To see the physical appearance of the Creative Labs Sound Blaster ZxR DBpro daughter card with its gray output Toslink female socket and its black input Toslink socket, do a Google image search as follows:
“sound blaster zxr” optical in dbpro “daughter card”

Is there any way to circumvent this sad state of affairs as a temporary work around for this problem with an interim software source code revision?

Could a software layer or function be added in audacity to parse the incoming data stream to determine the streams’ characteristics (possibly on the fly – in real time)?

Audacity doesn’t do much of anything in real time, so that’s the first problem right there. You’d be trying to plug into programming hooks that aren’t there.

Second, you’re volunteering the overworked programming group to design a patch for one (1) person. Probably not likely.


I just posted to the Creative Labs SB ZxR support forums:

Re: Creative Sound Blaster ZxR Optical s/pDIF Surround Recording

I noticed the following when I more closely examined the SB ZxR Mixer settings…

The Toslink / optical s/pDIF input levels, even when an AC3 surround 5.1 channel stream is being input displays level control sliders for only Left and Right channels, when there should be 6 channels.

Creative Labs Dolby is improperly being handled within both their driver and application software for the sound card, or the card itself is designed NOT to handle properly multichannel AC3 in a dynamic fashion as provided by the source optical device.


If this is the case, I told the technical support contact submission web form, the unit is going right back to the store for a quick refund of all the money I wasted on this thing + its extended 3 year direct exchange warranty from the computer store, and I would give the thing a very bad review seeing as Hauppauge Computerworks has several HD Video Capture devices that capture 5.1 surround optically without any foul-ups of the AC3 Dolby streams, getting full 6 channel sound when received.