Digital audio basics

[Widjaja]

I've always wondered why display port has not replaced HDMI.

I heard quite a while back there was some sort of issue with them but I don't rmember where the link is which explained it.
Could be BS though so HDMI stays.

 

[FordGT90Concept]

HDMI stays for the same reason BluRay stays: they have too much corporate backing to be unseated.

 

[Widjaja]

HDMI stays for the same reason BluRay stays: they have too much corporate backing to be unseated.

^^I had a feeling this was the reason.

 

[LAN_deRf_HA]

Why isn't this in the Audio forum?

Good question. That's been driving me nuts. Mods never seem inclined to move these threads into the audio forum. A lot of people don't even see that it's there yet. How are they going to learn if threads aren't getting moved?

 

[twilyth]

I reported my own thread and asked that it be moved. Sorry guys. I did check the front page so I'm not sure how I missed it.

The purpose of this thread was to get information on using digital audio rather than sound cards and analog audio. For most people, analog audio should be fine as long as you're using amplified speakers. But if you want standard unamplified speakers that are more toward the audiophile end of the spectrum, you have to go with something like a integrated amp or amp/pre-amp setup. In that case, since you will almost invariably have hdmi, toslink and s/pdif inputs, it's pretty pointless to spend a couple hundred bucks on sound card that's only going to give you line-level outputs anyway.

One of the things I'll try to get around to eventually is modifying the reserved posts to cover things like the s/pdif headers available on most m/b's and your options for using it if you decide to go that route (hat tip to streetfighter2).

 

[Easy Rhino]

i agree that hdmi is far superior to analog with the right equipment. hell, even with high scale digital equipment hdmi is better.for instance, if you can't tell the difference between dts-hd and dts then you have a shit system and then should not care about hdmi.

 

[Funtoss]

HDMI!! i wish my z 2300 could be converted to hdmi??

 

[slyfox2151]

HDMI!! i wish my z 2300 could be converted to hdmi??

wtf would HDMI give you over optical/coax....??


nothing.

 

[streetfighter 2]

if you can't tell the difference between dts-hd and dts then you have a shit system and then should not care about hdmi.

Originally Posted by AuralXTC
There is a difference but it's neither huge or negligible.

Most of the differences come with regards to LFE/bass quality and "air" or "detail". I find ambience/atmospherics are quite a bit better with the added resolution, and big action scenes benefit from a greater clarity due to the extra breathing room. This results in slightly smoother panning between speakers and an overall more "cohesive" and less "congested" soundfield imo.

Again, it's not huge but it's noticeable, a bit more than "subtle". Although it does vary from film to film and mix to mix. I think a lot of it has to do with having a room/equipment capable of resolving said differences, too.

In a nutshell I don't think anyone could tell the difference between DTS-HD and DTS on a movie like, As Good as It Gets, provided they didn't do a really lousy job on the encode. On the other hand the tunnel scene in The Dark Knight . . .

(My assumptions include that the system is already tuned.)

 

[slyfox2151]

i agree that hdmi is far superior to analog with the right equipment. hell, even with high scale digital equipment hdmi is better.for instance, if you can't tell the difference between dts-hd and dts then you have a shit system and then should not care about hdmi.

except HDMI also gives you 7.1 vs 5.1 from optical/coax....

 

[Easy Rhino]

In a nutshell I don't think anyone could tell the difference between DTS-HD and HD on a movie like, As Good as It Gets, provided they didn't do a really lousy job on the encode. On the other hand the tunnel scene in The Dark Knight . . .

(My assumptions include that the system is already tuned.)

True, certainly the encode makes a difference AND the genre of the movie. As a rule though I would say that if you cannot tell the difference between DTS and DTS-HDMA then you your system isn't up to the task.

except HDMI also gives you 7.1 vs 5.1 from optical/coax....

and optical cannot stream DTS-HDMA.(im referring to the actual lossless trackon a bluray, not the lossy core track which is essentially just DTS, or a compressed track.)

 

[LAN_deRf_HA]

If you have a soundcard and you're doing hdmi audio through your graphics card is your soundcard still doing anything? Or does the card's onboard audio chip and hdmi drivers take over? Cause that would suck and make for a good reason to stick with optical.

 

[Dent1]

If you have a soundcard and you're doing hdmi audio through your graphics card is your soundcard still doing anything? Or does the card's onboard audio chip and hdmi drivers take over? Cause that would suck and make for a good reason to stick with optical.

The soundcard does nothing! The new generation of video card's handle the audio independantly (on different applications)

You can run HDMI via your video card and run your soundcard via optical simultaneously if that's what you desire?

 

[twilyth]

If you have a soundcard and you're doing hdmi audio through your graphics card is your soundcard still doing anything? Or does the card's onboard audio chip and hdmi drivers take over? Cause that would suck and make for a good reason to stick with optical.

The soundcard does nothing! The new generation of video card's handle the audio independantly (on different applications)

You can run HDMI via your video card and run your soundcard via optical simultaneously if that's what you desire?

Exactly. If you right click the speaker in the task tray and select playback devices, you will see all of the devices available. On most systems with an onboard audio chipset, you will see "speakers high def audio device", digital audio (s/pdif) and digital audio (hdmi) - probably with a few duplicates.

My active HDMI connection shows up as syncmaster since that is the monitor at the end of the hdmi chain (gt210 -> yamaha receiver -> syncmaster).

in most audio applications you can select which device you want to use. Otherwise, it will be whatever you have set as the system default in playback devices.

 

[slyfox2151]

and optical cannot stream DTS-HDMA.(im referring to the actual lossless trackon a bluray, not the lossy core track which is essentially just DTS, or a compressed track.)

you said people should not care about HDMI if they cannot tell the difference between DTS and DTS-HD...

i gave a reason why people do care... it gives more channels.

 

[Jetster]

I've always wondered why display port has not replaced HDMI.

I heard quite a while back there was some sort of issue with them but I don't rmember where the link is which explained it.
Could be BS though so HDMI stays.

Displayport is meant to replace DVI. Not HDMI

 

[slyfox2151]

needs more thunderbolt to replace all connectors

 

[Wrigleyvillain]

Audiophiles, especially those with lots of cash, are all insane.

 

[LAN_deRf_HA]

Do nvidia and amd cards offload open al processing? If they do it won't be such a loss not having a soundcard. The only settings I still use on my forte are treble. Over time the other crap just started to seem pointless to me. Back on the fatality I needed the equalizer and the crystalizer. With the forte it seems less is more.

 

[twilyth]

Audiophiles, especially those with lots of cash, are all insane.

Yeah, at a certain point that's true. I spent about $1500 just for the front and center channels on one system but that barely rates the low-end of what is considered "audiophile". I was looking at some Bowers and Wilkinson speakers and may try giving them a listen if I get to a decent shop some day. But even researching the NHT's, most audio publications don't even start doing reviews until the price is at least $1000 per box.

Having said that though, the NHT's are really amazing and would consider upgrading the other channels - but not any time soon.

I'm sure at some point it becomes impossible to hear the difference and what you're really paying for is bragging rights but I think that point is probably at a price point fairly well beyond what I've been paying.

Do nvidia and amd cards offload open al processing? If they do it won't be such a loss not having a soundcard. The only settings I still use on my forte are treble. Over time the other crap just started to seem pointless to me. Back on the fatality I needed the equalizer and the crystalizer. With the forte it seems less is more.

I don't understand the question. What do you think is being off-loaded? HDMI ports on video cards just pass the digital data to the receiver. It's just a datastream.

 

[BumbleBee]

a beautiful sight

 

[streetfighter 2]

I don't understand the question. What do you think is being off-loaded? HDMI ports on video cards just pass the digital data to the receiver. It's just a datastream.

He's talking about the DSP chip on a sound card which would usually do the 3D positional sound, effects, and provide support for APIs like OpenAL. It's a good question and I'm still looking for an answer. I'll edit my post if I find one . . .

For now this is the best I can find:

[OpenAL] Hardware support is enabled for many Creative and NVIDIA audio devices
under Windows as well.
. . .
If the hardware consists only of an addressable output buffer, then
OpenAL must be implemented almost entirely on the host CPU.

 

[twilyth]

He's talking about the DSP chip on a sound card which would usually do the 3D positional sound, effects, and provide support for APIs like OpenAL. It's a good question and I'm still looking for an answer. I'll edit my post if I find one . . .

For now this is the best I can find:

I looked at the wikipedia entry and it seems like it is meant to simulate 7.1 audio over one or 2 channels. Is that very widely used? I would think it would be a lot easier to take 7.1 digital audio and try to reproduce that in the receiver or speaker hardware. Isn't that what sound bars do? Personally I'd have to hear it to believe you can reproduce the same soundstage as with 8 channels properly deployed, but IDK.

 

[streetfighter 2]

So here's what I found on the question of OpenAL support on graphics cards . . .

Graphics cards do not support OpenAL

I was only able to find circumstantial evidence to support this but it is reasonable to me. I checked the specifications for the HD 6850, GTX 580 and H67 onboard to see whether they support OpenAL or any kind of hardware support; they did not. Interestingly though I found this bit about H67 showing that Intel's implementation of DisplayPort is heavily gimped.

When using HDMI output OpenAL processing is pushed to the CPU

The evidence I have supporting this comes almost entirely from one quote in the OpenAL 1.1 specification.

If the hardware consists only of an addressable output buffer, then
OpenAL must be implemented almost entirely on the host CPU.

Prior to including an HD audio controller on graphics cards with HDMI output, you had to attach an internal SPDIF cable to the graphics card from a motherboard/soundcard header in order to get sound through HDMI. If Windows 7 includes a software driver that performs this function then it should be possible to run OpenAL on a supported audio controller and then "pipe" it to the graphics card's audio controller. I'm not presently aware if such a system exists.​

I looked at the wikipedia entry and it seems like it is meant to simulate 7.1 audio over one or 2 channels. Is that very widely used?

As far as I know OpenAL is very similar to DirectSound but OpenAL provides hardware support on the newer versions of Windows (whereas DirectSound hardware support was dropped in Vista+). I do not believe that simulating 7.1 over 2 channels is a feature of OpenAL. Like other 3D sound APIs, you simply tell it where you want a sound to be in a 3D space, and what the sound is, and then OpenAL will take care of transforming and placing the sound with regard to whatever setup you have (stereo, 2.1, 4.1, 5.1, etc.).

I would think it would be a lot easier to take 7.1 digital audio and try to reproduce that in the receiver or speaker hardware. Isn't that what sound bars do?

I believe you are correct, that is what sound bars do. I don't think there have been many standard terms adopted in the field of sound bars and simulated multichannel audio but I've heard virtual surround and Dolby Virtual Speaker thrown around a bit. I really don't know much about how these technologies work.

 

[Thatguy]

i agree that hdmi is far superior to analog with the right equipment. hell, even with high scale digital equipment hdmi is better.for instance, if you can't tell the difference between dts-hd and dts then you have a shit system and then should not care about hdmi.

Willing to take that double blind listening test ?