ALC887 onboard vs. Vantec 7.1 vs. X-Fi ExtremeMusic - all digital

[AnitaPeterson]

Howdy folks,

I have a new HTPC build ahead of me, and I'm trying to figure out which way to go.

The machine will be connected to an audio receiver via SPDIF (coaxial, not optical), which would decode the multichannel Dolby Digital/DTS streams.

The motherboard uses the Realtek ALC887 chip, and has a SPDIF header, which accepts one of those bracket adapters that add an optical and a coaxial digital output.

I also have a Vantec 7.1 card with coaxial output, based on a Via Envy 24 chip (http://www.vantecusa.com/en/product/view_detail/455).

I can also extract a Creative X-Fi XtremeMusic from an older machine, but that would be a bit of a hassle. It's possible, but I'd rather not do it unless there's a clear benefit over the previous two solutions.

Considering that all I want is good digital multichannel audio, would you say that pass-through via the bracket will be enough, or should I go the "discrete card" route (whether by using the Vantec or by cannibalizing the X-Fi)?

Decisions, decisions....

 

[nsafreak]

Go with the bracket solution. The output from any of the solutions listed is going to be the same and your receiver is what's going to be all of the audio processing.

 

[mfenn]

Go with the bracket solution. The output from any of the solutions listed is going to be the same and your receiver is what's going to be all of the audio processing.

:thumbsup: The audio codec hardly doing anything in this use case, you just need something to take the bits from the CPU and convert it to S/PDIF signalling.

 

[postmortemIA]

:thumbsup: The audio codec hardly doing anything in this use case, you just need something to take the bits from the CPU and convert it to S/PDIF signalling.

Except that some HW cards can create nice multichannel audio, and some cheap onboard don't.

 

[Lean L]

I know that the consensus is that if you use digital out, sound cards don't do too much.

The logic is sound but every time I try onboard sound for spdif/optical it sounds like absolute garbage especially in games. It sounds like someone put some saran wrap and a think layer of plastic in front of my speakers.

Just my observation.

 

[mfenn]

Except that some HW cards can create nice multichannel audio, and some cheap onboard don't.

The OP is looking to bitstream, so DD Live encoding isn't relevant in this case.

 

[mfenn]

I know that the consensus is that if you use digital out, sound cards don't do too much.

The logic is sound but every time I try onboard sound for spdif/optical it sounds like absolute garbage especially in games. It sounds like someone put some saran wrap and a think layer of plastic in front of my speakers.

Just my observation.

Most likely what you're noticing is that digital signals don't get the same EQ as audio ones do. In fact they generally get no EQ because the idea is that you will do any EQ that you might want downstream at the DAC. Which makes sense because then you're not taking the latency hit of decoding and re-encoding the signal.

 

[Lean L]

I'm talking about optical vs optical so the DAC is always in the receiver.

I'm convinced there is some post processing done at the audio processor level that we probably all take for granted. Is EAX still alive? Last I heard there was a way to use it but no software even tries to anymore?

 

[AnitaPeterson]

OK... Here's an update.

I installed the bracket and connected the coaxial digital cable to my Onkyo receiver.

I then played a DD (5.1) and DTS-encoded DVD, and the receiver reports a stereo (PCM 2.0) input stream.

I looked in the Realtek control panel, and there's no option to change the signal..

Not sure what to do right now.

I came across a TechPowerUp forum thread which lists unofficial Realtek drivers which can enable DD and DTS, and I guess that could be my next move.

I also discovered a Xonar DG card among my spare parts, but was dismayed to read that it only outputs stereo PCM.

 

[nsafreak]

I'll see if I can do some checking with my setup when I get home but you should be able to bitstream with the official drivers. I just can't recall the setting offhand.

 

[nsafreak]

Ok I have checked and I'm able to bitstream Dolby Digital and DTS Audio on my system with ALC892 although it shouldn't be too differemtn from ALC887. Make sure in the digital output properties you have both DTS Audio and Dolby Digital checked otherwise it will downconvert and output PCM stereo.

 

[mfenn]

Ok I have checked and I'm able to bitstream Dolby Digital and DTS Audio on my system with ALC892 although it shouldn't be too differemtn from ALC887. Make sure in the digital output properties you have both DTS Audio and Dolby Digital checked otherwise it will downconvert and output PCM stereo.

:thumbsup: Correct. The playback properties should look something like this:

 

[AnitaPeterson]

Thanks for the help, folks, I think I nailed it!

Yes, the properties showed that I can send both DTS and DD, as well as 44.1, 48.0 and 96.0 kHz signals to the receiver.

It turns out that my VLC was set for "default" - and somehow, it still thought that's just stereo.... Once I chose "DirectX audio output" and added a checkmark in the "Use SPDIF if available" box, the DTS and DD lights on the receiver lit up...

Whew, that was a head-scratcher!

 

[AnitaPeterson]

Just in case anyone's curious, this is the thread I was referring to: http://www.techpowerup.com/forums/t...olby-digital-live-and-dts-interactive.193148/

It looks like I don't need to do any of these experiments, but it's good to have a reference...

 

[mfenn]

Glad you got it working! :thumbsup: