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I have an HTPC that I'm feeding analog 7.1 speaker output.

I just recently changed the PC, I used to have SB X-Fi via PCI (not PCI-e, it was an old computer). The new HTPC has Realtek 892 onboard that does 7.1 and I also have a PCI-e soundcard that has C-Media 8828 chipset that also does 7.1. When it comes to 7.1 audio, is there really a difference here? What about Dolby and all the permutations that go along with it?

I hooked up the Realtek to my 7.1 system and ran some sound tests. It sounded pretty good. I hooked up the C-Media and ran the same tests, it sounded pretty good too. I have some 7.1 audio files that ping speakers and dynamic range.

Is there one chipset that isn't "compatible" with Dolby or such? I have Power DVD 15 for my playback. In that software it says it's playing back Dolby Pro Logic. Does anyone really know how Dolby or surround sound for that matter differ on these chipsets, compared to say a Xonar DX2 or whatever creative's latest card is?

If you're using analog Dolby is mostly irrelevant outside of upmixing, and it's merely a question of who has better surround software and component quality. I can't tell you which of your cards is better because I haven't used either, and listing the chipset isn't enough information, but you should be able to find what you need from google. That or try each out and pick what you like better.

PowerDVD is decoding Dolby to your speakers. If you were using digital, your external receiver would be decoding it. DDL on the other hand, takes a live source, encodes it digital, and passes it to the receiver. I haven't used DDL, but I think that can potentially add unnecessary latency and is pointless if you have a good soundcard. It's like live streaming your game video, then watching your live stream to game instead of directly off your monitor.

The onboard realtek is likely to give you better capabilities than an ancient PCI X-Fi, but it's worth checking that it doesn't pick up any high-frequency interference from the motherboard and pass it over to the analogue outputs.

Modern boards are much better at this, but even decent Haswell boards were capable of picking up EMI and passing it through to the analogue outputs.

Run Furmark and test the onboard sound. If you're happy with how clean the noise is, then leave it alone and call it a day!

Why not HDMI?

meerkt wrote:

Why not HDMI?

It depends on the OP's receiver. Older models may not have enough HDMI inputs, or none at all.

Thanks for all the feedback.

Since the Dolby Decoding is being done by the DVD software that's what made me start thinking that the sound card (onboard or PCIx) really doesn't matter since the audio signals are being split by the software and being passed to the applicable channel. What I thought that could make a difference is the SNR, op-amp boost or "upsampling" of a stereo signal to a surround sound format. At that point the drivers (software) is doing much of the work.

Saying that, PowerDVD does have software to upsample stereo as well so even that is starting to be a non-issue.

I don't use an external AMP for my Home Theater. I have a Creative 7.1 sound system that works very well for my size room 20'x15'. The system is fed by a 7.1 Analog sound card. Whether it be Creative, Asus, C-Media or whatever the bass unit doesn't care. It's just looking for analog 7.1 inputs(Front L/R, Rear L/R, Side L/R, Center/Sub). Video is fed to my Projector via HDMI. All my content is digital, either online or Blu Ray/DVD.

When I see sound cards that say "support Dolby Surround" or "Dolby Digital" I guess that means the sound card is capable of outputting the necessary amount of channels. It's not saying it has special hardware or drivers for Dolby per se. So ANY sound card that supports 7.1 can be said to support Dolby. As far as DDL, yeah, I don't have any optical inputs from external sources going to my HTPC. I cut the cord to my Satellite and Cable subscriptions. Purely online or DVD/Blu Ray.

I've been pleased with the Creative Sound Blaster SBX Pro Studio (PCIe) add-in card which replaced the X-Fi series. The X-Fi drivers were troublesome to install/configure and sometimes caused me driver conflict errors. I was about to switch over to ASUS Xonar before the SBX came out since I read good reviews on the Xonar series. The SBX software runs smooth and it has cinematic options for Dolby and DTS Connect. Realtek was always the generic driver with minimal controls IMO. I run 5.1 speakers and especially like mixer controls in the SBX software to adjust individual speaker volumes.