HTPC GURU help needed

[dennit]

Anyone know this answer - is SPDIF a fixed output?

I've used SPDIF on several HTPC setups on different computers, with different PVR software, but I'm not an expert. I've never had volume control on any of the different configurations. Mute works, but not volume. Of course, I've never wanted volume, as I've always sent audio to my audio system and used its volume control.

[mmatheny]

Thanx dennit - my curiosity is sated!

[Elmo Putney]

I use optical output, which is as far as I know SPDIF, and I have volume control, but only on the WAV slider in the volume panel IIRC.

[mmatheny]

I'll check to see if the wave output changes the volume, but doesn't matter, since all audio goes through my amp, adjusting the volume on it seems correct.

[dennit]

I'll check to see if the wave output changes the volume, but doesn't matter, since all audio goes through my amp, adjusting the volume on it seems correct.

Expanding on my earlier post, I have always used "DTS Connect" sending DTS encoded 5.1 audio over the S/PDIF connection. Again, I'm not an expert, but it is possible to configure the PC audio chip to send ordinary stereo digital over the S/PDIF. In this configuration, the PC has more control over the audio, but can't send 5.1. I suspect that you would have volume control when configured this way - but at the expense of surround sound.

[Elmo Putney]

Ahhh, yes I'm on 2 channel (the audiophile version )

[mmatheny]

Expanding on my earlier post, I have always used "DTS Connect" sending DTS encoded 5.1 audio over the S/PDIF connection. Again, I'm not an expert, but it is possible to configure the PC audio chip to send ordinary stereo digital over the S/PDIF. In this configuration, the PC has more control over the audio, but can't send 5.1. I suspect that you would have volume control when configured this way - but at the expense of surround sound.

What is "DTS Connect"?

[dennit]

What is "DTS Connect"?

Your PC has an audio chip. That chip can perform various functions depending on its design, and the driver can utilize those functions, depending on design. "DTS" refers to one of the two major competing surround sound format suppliers (the other is Dolby) and they have various standards and formats that they support and license. One of those formats licensed by DTS is called "DTS Connect" - it's a format licensed to PC manufacturers and/or chip manufacturers for encoding PC sound into a DTS format that can be sent within the constraints of the S/PDIF specs to an external amplifier, where it gets recognized as DTS format and decoded into 5.1 sound.

If your computer sound chip supports it, you will have a sound driver and a control program for your sound card that refers to it. There are other flavors with different names.

I think of it this way - S/PDIF is designed to send uncompressed stereo. DTS is compressed audio 5.1. The built in PC volume function occurs fairly late in the PC audio process and would need to uncompress, change the compressed signal and recompress the audio back to DTS.

I'm sure that some research on Wikipedia would send you to details at the DTS and Dolby sites that would explain this better.

[mmatheny]

Thanx - did some research, and my nVidia based MB (GeForce7050PV, Realtek ACL662) says it supports DTS connect - will investigate further!!