5.1 audio through SPDIF optical, Windows volume control.

[Vanguard]

Hi.

 

I have a soundbar with rear speakers, which can only be connected with an optical SPDIF cable.

 

With the onboard audio, the only way to get surround sound, with 5.1 AC3, is by enabling passthrough. Enabling passthrough disables the Windows volume control.

 

I find this annoying, so I wonder whether a USB soundcard, with Dolby Digital Live, would allow me to listen to 5.1 AC3 audio without enabling passthrough, and letting me control the volume with the windows master volume control?

[Kalm_Traveler]

8 minutes ago, Vanguard said:

Hi.

 

I have a soundbar with rear speakers, which can only be connected with an optical SPDIF cable.

 

With the onboard audio, the only way to get surround sound, with 5.1 AC3, is by enabling passthrough. Enabling passthrough disables the Windows volume control.

 

I find this annoying, so I wonder whether a USB soundcard, with Dolby Digital Live, would allow me to listen to 5.1 AC3 audio without enabling passthrough, and letting me control the volume with the windows master volume control?

I use a Creative Labs Sound Blaster Z sound card to pipe encoded 5.1 over optical to my home AVR, partly because I don't want the HDMI connected since the PC sees the AVR or TV as a second monitor which I don't want to use most of the time, and partly because Creative's control panel lets you set up fake surround for stereo sources so I get fuller sound from my home theater setup. 

If I run the sound over HDMI - true multi-channel sources like blu ray or dvd rips will play their 5.1/7.1 correctly, but stereo stuff only comes out of FL and FR (which is technically accurate for what it is).

 

As far as Windows volume control - when using the Sound Blaster's DTS Connect or DDL to put out 5.1 over optical, the sound control doesn't work because it is set to adjust whatever the default output device is, which in this case can be output interfaces only, 'Speakers', 'SPDIF Digital Out', etc where the only volume slider that affects volume is one called 'What You Hear' in the Creative control panel. I have not yet figured out a way to link the Windows volume slider to that adjustment.

[an actual squirrel]

The answer is yes. The volume control only works on pcm.  So you could change the volume in pcm, and then dolby digital live will change the pcm to dolby digital. The issue then is if the original file had dolby digital, then you are encoding lossy audio again with lossy compression. So somewhat needless quality loss.