# Digital audio basics



## twilyth (Jun 20, 2011)

I learned a great deal in a recent trouble-shooting thread I had posted and I thought a lot of the information presented there was worth codifying so as to make it easily available to others interested in digital audio.

Special thanks to streetfighter 2 and BumbleBee but also everyone who contributed including Sinzia, Jetster and hat.

I'm probably going to overlook a lot of valuable information, not to mention making any number of errors, so I'm reserving a few slots for later additions and will edit posts as my errors are pointed out.  Please post and indicate any information that should be included and I will either plagarize you post to include it the main sequence or edit it as necessary to keep it clean and easy to understand.

*HDMI is superior to analog and other forms of digital audio*

Even people who are tech savvy may not realize that the HDMI interface provides a far superior method of reproducing audio from digital sources.  The audio functions are generally seen as a convenience which allows you to have a single cable for DVI video and digital audio.  But in fact, it goes so far beyond that.

HDMI can handle up to 8 24-bit channels with sample rates up to 192khz (or higher).  It can also handle a variety of compression protocols, although the extent of it's capabilities are hardware dependent.



> For digital audio, if an HDMI device supports audio, it is required to support the baseline format: stereo (uncompressed) PCM. Other formats are optional, with HDMI allowing up to 8 channels of uncompressed audio at sample sizes of 16-bit, 20-bit and 24-bit, with sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz and 192 kHz.[21][45] HDMI also supports any IEC 61937-compliant compressed audio stream, such as Dolby Digital and DTS, and up to 8 channels of one-bit DSD audio (used on Super Audio CDs) at rates up to four times that of Super Audio CD.[45] With version 1.3, HDMI supports lossless compressed audio streams Dolby TrueHD and DTS-HD Master Audio.[45]



This means that if you have a relatively recent discreet video card or IGP, you have everything you need to produce the best sound from any digital source.

*HDMI vs S/PDIF*

Most motherboards have the ability to output an S/PDIF signal, however, optical transfer of digital audio has numerous limitations.  For example an S/PDIF connection can only handle 4 channels at a 44khz sample rate.  And while it technically has 24-bit resolution, it is designed for only 20 bit.

In addition, S/PDIF can't handle many of the protocols that HDMI can.


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## twilyth (Jun 20, 2011)

reserved 1


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## twilyth (Jun 20, 2011)

reserved 2


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## twilyth (Jun 20, 2011)

reserved 3


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## streetfighter 2 (Jun 20, 2011)

Mussels actually made a similar thread, though it doesn't get into much of the real technical grit:
http://www.techpowerup.com/forums/showthread.php?t=141676


twilyth said:


> For example an S/PDIF connection can only handle 4 channels at a 44khz sample rate.


Where'd you read that?

SPDIF can handle DTS and AC3 just fine.  It just can't do DTS-HD, Dolby TrueHD or anything more than 2 channels PCM/lossless.

If you try to run DTS-HD or Dolby TrueHD thru SPDIF it should convert to DTS/Dolby core (aka compressed/encoded stream).  I've tested this myself and I honestly can't tell the difference between master and encoded on my sound system, but it might just be the audio clip I'm using.

In order to use DTS-HD and/or Dolby TrueHD with your HT and HTPC you need:
1) a graphics card that can bitstream those formats (HD 5XXX +, GTX 460, GTX 5XX+, H67+, etc.)
2) a couple HDMI 1.3+ cables
3) a recent version of arcsoft or powerdvd (w/ HD bitstream)
4) a DTS-HD or Dolby TrueHD source
5) a compatible receiver
6) a compatible display
7) an HDCP compliant datapath (for bru-lays )

It's so easy . . . 


twilyth said:


> Most motherboards have the ability to output an S/PDIF signal, however, optical transfer of digital audio has numerous limitations.


Optical or coaxial transfer of audio doesn't have limitations (as far as I know), but SPDIF does.  The SPDIF protocol is old but the cables themselves, RCA coax and TOSLINK, have enough bandwidth to transfer DTS-HD and Dolby TrueHD.  As I understand it, the only reason that DTS-HD and Dolby TrueHD aren't bitstreamed through a RCA coax or TOSLINK is because the SPDIF protocol does not provide HDCP.

Kinda hard to get a good source here . . . This is the best I could do:


> Originally Posted by *JiffOrange*
> 
> 
> _SPDIF has sufficient bandwidth for HD audio but the protocal developed by sony and philips doesn't support anything over 2 channel_ [PCM/lossless] _...since the audio path is not compatable with AACS and no current equipments carries the required capabilities it is very unlikeky you will ever get HD audio over SPDIF._





twilyth said:


> In addition, S/PDIF can't handle many of the protocols that HDMI can.


SPDIF is the protocol.  I think you're referring to the "format" (sometimes informally called a codec).


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## twilyth (Jun 20, 2011)

This is why you got the gilded invitation with the fancy calligraphy dude.  What?  You think it's because I like you?  

So what are the limitations on S/PDIF?  I know bit rate is one.  

Also, maybe you could decode this paragraph for us mere mortals since it doesn't sound good but that's the most I can get from it.



> Because the receiver cannot control the data rate, it instead has to avoid bit slip by synchronising its conversion with the source clock. This means that S/PDIF cannot fully decouple the final signal from influence by the analogue characteristics of the source or the interconnect, even though the digital audio data can normally be transmitted without loss. The source clock may carry inherent jitter or wander, and noise or distortion introduced in the data cable may further influence the process of clock recovery.[5][6][7] If the DAC does not have a stable clock reference then noise will be introduced into the resulting analogue signal. However, receivers can implement various strategies which limit this influence.[7][8]
> 
> TOSLINK cables do not work well (and may even suffer permanent damage) if tightly bent or squashed by, say, a misplaced foot. Their high light-signal attenuation limits their effective range to 6.1 metres (20 ft) or so. On the other hand, TOSLINK cables are not susceptible to ground loops and RF interference, as coaxial cables are.[9]
> 
> S/PDIF lacks flow control and retransmission facilities, which limits its usefulness in data communications applications.



Thanks again


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## Thatguy (Jun 20, 2011)

twilyth said:


> I learned a great deal in a recent trouble-shooting thread I had posted and I thought a lot of the information presented there was worth codifying so as to make it easily available to others interested in digital audio.
> 
> Special thanks to streetfighter 2 and BumbleBee but also everyone who contributed including Sinzia, Jetster and hat.
> 
> ...




   I'll bet you a whole boatload of cash that you can't hear the difference between 16b 44.1khz and 24b 96khz and 24b 192khz.


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## twilyth (Jun 20, 2011)

I've done a couple of impromptu tests and I know I can tell the difference between some mp3's and flac.  But honestly, I haven't really tried to find my limits.  I think that most lossless formats sound better and I try to avoid the lower resolution stuff.  I think a lot of that preference though is due to artifacts that I tend to notice in tracks that are aggressively compressed.  I'm particularly sensitive to resonances that don't seem to be part of the music.

The point though is, that if you want the best possible sound reproduction, HDMI is the way to go.  And while so much in the realm of audio depends on what you're willing to pay, HDMI gives you the best reproduction for virtually no additional cost - whether you can appreciate the quality or not almost doesn't matter.


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## Thatguy (Jun 20, 2011)

twilyth said:


> I've done a couple of impromptu tests and I know I can tell the difference between some mp3's and flac.  But honestly, I haven't really tried to find my limits.  I think that most lossless formats sound better and I try to avoid the lower resolution stuff.  I think a lot of that preference though is due to artifacts that I tend to notice in tracks that are aggressively compressed.  I'm particularly sensitive to resonances that don't seem to be part of the music.
> 
> The point though is, that if you want the best possible sound reproduction, HDMI is the way to go.  And while so much in the realm of audio depends on what you're willing to pay, HDMI gives you the best reproduction for virtually no additional cost - whether you can appreciate the quality or not almost doesn't matter.



   I will bet you large sums of money that you cannot here the difference in a proper listening enviroment.Using double blind methodolgys.


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## streetfighter 2 (Jun 20, 2011)

twilyth said:


> So what are the limitations on S/PDIF?


It won't do:

DTS-HD
Dolby TrueHD
PCM/lossless > 2 Channels



twilyth said:


> Also, maybe you could decode this paragraph for us mere mortals since it doesn't sound good but that's the most I can get from it.


Unfortunately I am also a mortal .

I think it's just saying that since the clock is propagated from the source and employs no error recovery mechanism then there is potential that a distorted clock signal could prevent the DAC from lossless reception.  Also check out bit slip.

The part about breaking TOSLINK cables is relevant to all fiber optic cables.


twilyth said:


> The point though is, that if you want the best possible sound reproduction, HDMI is the way to go.


HDMI is the way to go for HT nuts (like me).  For audiophiles who are often more interested in stereo (and triode amps :shadedshu) then SPDIF and an outboard DAC may be the right choice.  (source)

Or you could skip the whole affair and buy a bloody studio sound card. (source)


Thatguy said:


> I will bet you large sums of money that you cannot here the difference in a proper listening enviroment.Using double blind methodolgys.


Audiophiles are some of the dumbest people I've met.  Some of them believe in shit as retarded as bi-wiring.  Also check this.


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## twilyth (Jun 20, 2011)

OK, so most of the limits with s/pdif have to do with bandwidth in the sense of not being able to reproduce high bit rate?  Is that a fair summary?

So if you want to handle more than 2 channels at a high bitrate, either you use HDMI or analog outputs from a sound card?

I'm just going to try to hit the basics so i'm going to gloss over the more technical topics.

That was an interesting article about audiophile lies.


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## Thatguy (Jun 20, 2011)

streetfighter 2 said:


> Audiophiles are some of the dumbest people I've met.  Some of them believe in shit as retarded as bi-wiring.  Also check this.



   I have a nice little studio at my house. I am well aware, although I like the sound COLORing of analog gear.


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## slyfox2151 (Jun 20, 2011)

no offence, but i really can tell the difference between 44100 and 96000 @ 16b.

i have no way of proving this to you however, but there is a clear difference in sound.
(i could not tell you witch sound was 44 or 96 in a double blind test, but i could tell you if it sounded different from the last test.)




oh and HDMI is not ALWAYS Superior to analogue.... if you have shitty DACs it doesn't matter how the digital audio got there.










if my receiver supported it, i would be running 4 analogue cables to it instead of HDMI, then i could buy and make use of a high end sound card with high quality DACs. not to mention upmixing / playback of 2.0 5.1 7.1 is a pain in the ass having to change the output settings in windows. 

my receiver wont support any upmixing if i set my sound card to 5.1 or 7.1 output even if only playing  2 channel audio sauce. playing a blu ray in 5.1/7.1 wont work if the sound card is set to 2 channel to allow for upmixing.
(i dont upmix music i leave it play in stereo, but i have a lot of 2 channel movies i like to upmix.)


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## seronx (Jun 20, 2011)

slyfox2151 said:


> no offence, but i really can tell the difference between 44100 and 96000 @ 16b.
> 
> i have no way of proving this to you however, but there is a clear difference in sound.
> (i could not tell you witch sound was 44 or 96 in a double blind test, but i could tell you if it sounded different from the last test.)
> ...



Wait, don't you mean ADCs?
Analog->Digital Converters

because going to

Digital->Analog seems pretty lossless since digital streams as long as they are received properly can be decoded pretty well
meaning
Digital->Analog is not what you should be worrying about

Everything played on the computer unless you can somehow rip Super Audio CDs
is pretty much well 16bit aka Analog


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## slyfox2151 (Jun 20, 2011)

seronx said:


> Wait, don't you mean ADCs?
> Analog->Digital Converters
> 
> because going to
> ...



OH?
so what would be the need for a high end audio card then? i assume this uses DACs, the quality of witch would partly deter-men the level of audio quality.





how is 16bit analogue? my understanding is its the total possible range of the dynamic level.


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## Thatguy (Jun 20, 2011)

slyfox2151 said:


> no offence, but i really can tell the difference between 44100 and 96000 @ 16b.



   How much money are you willing to bet on this with a double blind listening test ?


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## BumbleBee (Jun 20, 2011)

yeah the winner gets to move in with this guy lol


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## Widjaja (Jun 20, 2011)

I can not hear the difference between 44.1 and 196 either.
I Fired up Cakewalk Sonar 8.5 PE and ran some soft synth recordings.
Absolutely identical in sound to my ear.
Only difference to me was the file size.


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## streetfighter 2 (Jun 20, 2011)

twilyth said:


> OK, so most of the limits with s/pdif have to do with bandwidth in the sense of not being able to reproduce high bit rate?  Is that a fair summary?


You've got great questions but it's hurting my head trying to figure out how to answer them.  

As I wrote in a previous (heavily edited) post, as far as I can tell, SPDIF's limitations are merely a failure to update the standard for use with multi-channel master audio.  Furthermore there is little motivation for such an update because SPDIF is incapable of providing content protection (which HDMI does provide).


slyfox2151 said:


> if my receiver supported it, i would be running 4 analogue cables to it instead of HDMI, then i could buy and make use of a high end sound card with high quality DACs. not to mention upmixing / playback of 2.0 5.1 7.1 is a pain in the ass having to change the output settings in windows.


Most modern receivers will ADC (and subsequently DAC) an analog input signal, rendering your high quality DAC ineffective anyway .


slyfox2151 said:


> oh and HDMI is not ALWAYS Superior to analogue.... if you have shitty DACs it doesn't matter how the digital audio got there.


I agree.  Your audio performance is only as good as the weakest element in the audio chain.


slyfox2151 said:


> my receiver wont support any upmixing if i set my sound card to 5.1 or 7.1 output even if only playing  2 channel audio sauce. playing a blu ray in 5.1/7.1 wont work if the sound card is set to 2 channel to allow for upmixing.
> (i dont upmix music i leave it play in stereo, but i have a lot of 2 channel movies i like to upmix.)


You can use ffdshow filters to upmix stereo to multi-channel (either using Dolby Pro Logic II or custom speaker matrix) and then have the processed signal bitstreamed to the receiver.


seronx said:


> Digital->Analog seems pretty lossless since digital streams as long as they are received properly can be decoded pretty well
> meaning
> Digital->Analog is not what you should be worrying about


I'll write about why this is inaccurate later . . . preferably after I get on a computer with MATLAB.


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## Thatguy (Jun 20, 2011)

Widjaja said:


> I can not hear the difference between 44.1 and 196 either.
> I Fired up Cakewalk Sonar 8.5 PE and ran some soft synth recordings.
> Absolutely identical in sound to my ear.
> Only difference to me was the file size.



There are some mix time and mix down reasons to consider higher bandwidths and bit depths, more dynamic headroom, more smearing of samples, give the end mix a bit more breathing room in some ways. same way running the tape speed higher improves the noise floor of tape, 


   but when it comes time to playback, I'll go grab my golden ear muffs and pretend away like th best of them.


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## slyfox2151 (Jun 21, 2011)

Thatguy said:


> How much money are you willing to bet on this with a double blind listening test ?



i dont belive i need to bet money here. when i switch between 44 and 96 on either my old z-5500s i could tell there was some sort of difference between them.
(using Optical)


if i had to guess, i belive i noticed the effect most on higher frequencys.


EDIT:
doing the same test on my newer sony system, i cannot hear a difference...


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## Thatguy (Jun 21, 2011)

slyfox2151 said:


> i dont belive i need to bet money here. when i switch between 44 and 96 on either my old z-5500s i could tell there was some sort of difference between them.
> (using Optical)
> 
> 
> ...



You have your answer. Now if your dealing with massively complex music with lots of dynamic range and many channels, that bit depth can help to give more realism to audio effect in a surround system, but its the bit depth and not the sampel rate that gives those benefits, most people have trouble with discerning 2db changes in db levels. Most modern music on the radio today has less then 8bit of dynamic range.


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## Widjaja (Jun 21, 2011)

BumbleBee said:


> yeah the winner gets to move in with this guy lol
> 
> http://images.blu-ray.com/htgallery/53912.jpg



The thing on the top right looks like a rice cooker!


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## FordGT90Concept (Jun 21, 2011)

twilyth said:


> *HDMI is superior to analog and other forms of digital audio*


Klipsch disagrees with you.  Hell, only Logitech and Apple have really embraced digital.  Why?  Because all speakers are analog because the human ear is analog.  If you have a digital decoder in your computer that is superior to those found in receivers, TVs, etc. you're going to get a richer sound sending an analog signal to the speakers than you will a digital one.

When it comes to audio, the only advantage of digital is fewer physical connections between the output device and the speakers.  When it comes to actual sound quality, it depends on the quality of digital decoders and amplifiers.


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## BumbleBee (Jun 21, 2011)

Widjaja said:


> The thing on the top right looks like a rice cooker!



I think it's a Teres Turntable and the one underneath with the yellow LED is a Soundsmith pre-amp.


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## Thatguy (Jun 21, 2011)

FordGT90Concept said:


> Klipsch disagrees with you.  Hell, only Logitech and Apple have really embraced digital.  Why?  Because all speakers are analog because the human ear is analog.  If you have a digital decoder in your computer that is superior to those found in receivers, TVs, etc. you're going to get a richer sound sending an analog signal to the speakers than you will a digital one.
> 
> When it comes to audio, the only advantage of digital is fewer physical connections between the output device and the speakers.  When it comes to actual sound quality, it depends on the quality of digital decoders and amplifiers.




   I will again ask another golden ear to take a double blind listening test.


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## Ra97oR (Jun 21, 2011)

I see this turning into a trainwreck real soon. 

First try this:
http://www.noiseaddicts.com/2009/03/mp3-sound-quality-test-128-320/

Result was easily noticeable on my setup. Took 1 play to spot it, second play to confirm it is indeed the right answer. If you can't hear the difference on that, don't bother arguing that 24bit 192kbps OF THE SAME RECORDING at 16bit 44.1k is going to sound different, because I can't find any. Most the time the 24bit is just better mastered than the 16bit version. 

The thing about HDMI is most high end DACs are not readily accepting HDMI, it works on a Home Theatre situation, but a high end 2-ch built for music listening won't benefit from it and losing out on the higher quailty DACs and settle with a receiver.


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## FordGT90Concept (Jun 22, 2011)

Ra97oR said:


> First try this:
> http://www.noiseaddicts.com/2009/03/mp3-sound-quality-test-128-320/


First, which lossy compression was used nor its bitrate have anything to do with digital vs analog.  If your source is crap, it's gonna be crap no matter what.

Second, that "test" is BS because both "clips" are the same:

```
AudioPlayer.embed("audioplayer_1", {soundFile:"aHR0cDovL3d3dy5ub2lzZWFkZGljdHMuY29tL2F1ZGlvL2NsaXAxLm1wMw"});
AudioPlayer.embed("audioplayer_2", {soundFile:"aHR0cDovL3d3dy5ub2lzZWFkZGljdHMuY29tL2F1ZGlvL2NsaXAyLm1wMw"});
```

The difference is nil.




Ra97oR said:


> Result was easily noticeable on my setup.


You, good sir, have been a victim of confirmation bias.


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## BumbleBee (Jun 22, 2011)

cute, but Klipsch isn't the company they once were.


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## Irish_PXzyan (Jun 22, 2011)

I've a question,
I am going to replace my AV Receiver within the next month or two and I MUST get one that supports uncompressed LPCM 5.1 audio!
Only thing is, I have no idea how to figure out if a receiver supports it or not!

How do I go about figuring this out????

For example... does this support it?

http://cgi.ebay.ie/Onkyo-TXSR507-HD...s_Video_HomeCinemaSystems&hash=item35ad1ada99

Would this also support it?

http://cgi.ebay.ie/Yamaha-RXV467-3D...132?pt=LH_DefaultDomain_3&hash=item1c1c0a9624

If they do, how do you know?? if not! how do I find the ones that do!
I want to find them as cheap as I possibly can too!


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## BumbleBee (Jun 22, 2011)

Irish_PXzyan said:


> I've a question,
> I am going to replace my AV Receiver within the next month or two and I MUST get one that supports uncompressed LPCM 5.1 audio!
> Only thing is, I have no idea how to figure out if a receiver supports it or not!
> 
> ...



PS3 I take it?


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## Thatguy (Jun 22, 2011)

FordGT90Concept said:


> First, which lossy compression was used nor its bitrate have anything to do with digital vs analog.  If your source is crap, it's gonna be crap no matter what.
> 
> Second, that "test" is BS because both "clips" are the same:
> 
> ...



Do you wanna bet a million dollars on your ears ?


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## Irish_PXzyan (Jun 22, 2011)

BumbleBee said:


> PS3 I take it?



Maybe


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## FordGT90Concept (Jun 22, 2011)

Thatguy said:


> Do you wanna bet a million dollars on your ears ?


The source never lies.  They sounded exactly the same which is why I got suspicious and checked the source.


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## Thatguy (Jun 22, 2011)

FordGT90Concept said:


> The source never lies.  They sounded exactly the same which is why I got suspicious and checked the source.



Did it occur to you, that you just don't hear any better then anyone else ?Secondly, I belive the experiment fundementally proves something else. But I encourage you to track down Ethan Winer over at real traps, and tell him what you claim to hear. 

  I'll be over here with a bag of popcorn.


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## BumbleBee (Jun 22, 2011)

Irish_PXzyan said:


> Maybe



Yamaha.


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## seronx (Jun 22, 2011)

Thatguy said:


> Did it occur to you, that you just don't hear any better then anyone else ?Secondly, I belive the experiment fundementally proves something else. But I encourage you to track down Ethan Winer over at real traps, and tell him what you claim to hear.
> 
> I'll be over here with a bag of popcorn.



Did it occur to you that the files were both 128kbps?


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## Jack Doph (Jun 22, 2011)

seronx said:


> Did it occur to you that the files were both 128kbps?



The bitrate here wasn't what Ford argued - he simply stated they sounded the same and proved it by showing that both examples link to the same file


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## seronx (Jun 22, 2011)

Jack Doph said:


> The bitrate here wasn't what Ford argued - he simply stated they sounded the same and proved it by showing that both examples link to the same file



Yes, and it was a 128Kbps file

The person on the website wasn't comparing, but lied

128Kbps vs 320Kbps

I can do a CD-Rip right now and make a .rar/.zip and input

128Kbps, 160Kbps, 320Kbps, 768Kbps, and lossless

and you'll hear the difference on each level


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## temp02 (Jun 22, 2011)

seronx said:


> Did it occur to you that the files were both 128kbps?



Sorry but no, they aren't, you can download them yourself if you want:

```
http://www.noiseaddicts.com/audio/clip1.mp3 (320kbps)
http://www.noiseaddicts.com/audio/clip2.mp3 (128kbps)
```
What *FordGT90Concept* found on the source of the page isn't *exactly* what is being played by each player.

IMO, on this piece of audio the difference is not noticeable, since it doesn't have many high frequency sounds. Although on some other music, for instance house music MP3s, I can say that I do note the difference between the two.


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## seronx (Jun 22, 2011)

temp02 said:


> Sorry but no, they aren't, you can download them yourself if you want:
> 
> ```
> http://www.noiseaddicts.com/audio/clip1.mp3 (320kbps)
> ...



They both refer to clip2

aka. What streams to you is Clip 2


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## temp02 (Jun 22, 2011)

seronx said:


> They both refer to clip2
> 
> aka. What streams to you is Clip 2



If you don't believe in me or the pages author, debug the webpage or better yet, look at your firewall logs and you'll see that both clips are played in the correct order (the audio player isn't even made by the pages author).


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## LAN_deRf_HA (Jun 22, 2011)

So if you're using digital connectors there's no sound quality benefit to having a sound card? Just in open al offloading for games (assuming creative based)? Opamps are pointless now??? What's the solution for headphones then? I don't know of any hdmi headsets...


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## Thatguy (Jun 22, 2011)

LAN_deRf_HA said:


> So if you're using digital connectors there's no sound quality benefit to having a sound card? Just in open al offloading for games (assuming creative based)? Opamps are pointless now??? What's the solution for headphones then? I don't know of any hdmi headsets...



   There been all kinds of snake oil over the years regarding audio. What most are actually arguing about unknowingly is the way they prefer sound to be colored by a particular piece of gear. Which is fine, but misrepresenting this as a improvement one way or the other, is dishonest and ignorant.


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## Thatguy (Jun 22, 2011)

seronx said:


> Yes, and it was a 128Kbps file
> 
> The person on the website wasn't comparing, but lied
> 
> ...



well, this isn't a good test in reality. First off, almost every human can hear the encoding loss on MP3 format music at upto about 256kbps, IF they know what to listen for, also you loose dynamic headroom to. 

   But I am discussing difference between gold standard 16b 44.1khz and mp3 is rediculous. What you cannot hear the difference in will be 16b 44.1khz and 24b 96khz and 24b 192khz. Where you get improvements in these formats is as I mentioned, more smearing which lends a more analog quality to to the sound and more dynamic headroom specifically at the masterbus.


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## FordGT90Concept (Jun 22, 2011)

I took the initiative, grabbed my newest CD (best recording equipment and least damage to the disk) that has seen an optical drive only once before now and used WMP12 to rip a lossless wave (1411.2 kbps), MP3 @ 320 kbps, and MP3 @ 128 kbps (all 3 directly from the source disk).  The HT Omega was at 100% volume, propagating the channels from 2 (stereo) to 6 (stereo surround), and no DSP effects enabled.  The Klipsch Speakers were adding an additional 40dB boost.

Audicity showed pretty obvious differences between the 3 files but, in terms of how it sounds, they all matched (compared to lossless) to the ear which is all that actually matters.

I know you can tell the difference between 64 kbps MP3 vs 128 kbps but it would seem that anything higher than 128 kbps is moot unless you plan on converting it over and over and over again (each time losing a little more quality).


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## Thatguy (Jun 22, 2011)

FordGT90Concept said:


> I took the initiative, grabbed my newest CD (best recording equipment and least damage to the disk) that has seen an optical drive only once before now and used WMP12 to rip a lossless wave (1411.2 kbps), MP3 @ 320 kbps, and MP3 @ 128 kbps (all 3 directly from the source disk).  The HT Omega was at 100% volume, propagating the channels from 2 (stereo) to 6 (stereo surround), and no DSP effects enabled.  The Klipsch Speakers were adding an additional 40dB boost.
> 
> Audicity showed pretty obvious differences between the 3 files but, in terms of how it sounds, they all matched (compared to lossless) to the ear which is all that actually matters.
> 
> I know you can tell the difference between 64 kbps MP3 vs 128 kbps but it would seem that anything higher than 128 kbps is moot unless you plan on converting it over and over and over again (each time losing a little more quality).




   I clearly hear the encoding artifacts in the upper bands from 4k to 10k. Drives me batshit. Above 256k its not really problematic but below that, I can't stand it, its like a flickering flourescent ligh.


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## FordGT90Concept (Jun 22, 2011)

There might not have been any sounds that high in the song I was using.


----------



## streetfighter 2 (Jun 22, 2011)

I'd like to add my two cents on the human perceptible compression discussion.

In my experience I've seen files that could compress very well and sound virtually identical to their (far larger) lossless counterparts.  On the other hand I've encountered files that did not respond well to compression and a great deal of effort went into finding settings which allowed for almost no noticeable deterioration in the signal.  Feel free to simulate various compression settings in MATLAB, Sage, etc. and you'll see that there are times when high levels of compression lead to very little information loss and times when high levels of compression lead to massive signal corruption.

If I get around to it I'll post some examples but this thread is going to backlog my MATLAB work 


FordGT90Concept said:


> Klipsch disagrees with you.  Hell, only Logitech and Apple have really embraced digital.  Why?  Because all speakers are analog because the human ear is analog.  If you have a digital decoder in your computer that is superior to those found in receivers, TVs, etc. you're going to get a richer sound sending an analog signal to the speakers than you will a digital one.
> 
> When it comes to audio, the only advantage of digital is fewer physical connections between the output device and the speakers.  When it comes to actual sound quality, it depends on the quality of digital decoders and amplifiers.


Huh?  Digital is just a method of storage.  You're not sending digital to the speakers, the speakers are still getting analog (from the DAC on your receiver and then through an amp).  A digital decoder should be able to take any input signal and send it to the DAC with the same reliability that your computer computes pi (so 1 error for every 4E20E20 computations* roughly ?).**

Obviously then you can debate the quality of the DAC and amplifiers, which is an open topic IMO.  After a certain level of sophistication (and proper tuning) it just gets stupid and no one can tell the difference without some instrument (eg. SPL meter) assistance.

(IIRC) Lots of modern receivers will ADC any analog input signal, so you're still going to get sound that is only as good as the (in order). . .
-Analog input signal
-ADC
-(Optional) DSP
-DAC
-Amp
-Speakers

FFT anyone? 

*The number is fluff obviously, but it should be really big anyway. 
**You may also perform some DSP on the decoded signal prior to sending it to the DAC.


----------



## twilyth (Jun 22, 2011)

I listened to the 2 clips on 2 systems.  One has a Yamaha htr-5063 with polk monitor 40's and 30's plus RM8's for center and rear.  The other has a yamaha rx-v765 with nht 3-way's front and center and nht zeros and sub zeros for the back and side.

I could tell the difference on the first system right away.  it was subtle, but easy to pick the better sound.  

The second system has better specs and the NHT 3-way speakers are incredibly clean and flat.  I had a very hard time distinguishing on the second system even though it was technically better.  I even tried listening in just stereo rather than enhanced 7.1 and it was still a toss up.


----------



## FordGT90Concept (Jun 22, 2011)

The DAC is in my HT Omega card.  The Klipsch speakers only have a BASH amplifier. Three 6' cables run between the two.  No "errors" occur in between because it is simply a wave carried over a copper wire.  They would be considered "distortions" and if there are any, they aren't perceptible.


----------



## streetfighter 2 (Jun 22, 2011)

FordGT90Concept said:


> The DAC is in my HT Omega card.  The Klipsch speakers only have a BASH amplifier. Three 6' cables run between the two.  No "errors" occur in between because it is simply a wave carried over a copper wire.  They would be considered "distortions" and if there are any, they aren't perceptible.


Are you mocking me? 

We were discussing transmission, decoding and DAC of digital audio signals.  You made the claim that people were sending digital signals to their speakers.  I replied that this was inaccurate (with an explanation laden with my standard flair ).

You then replied that you are using your sound card and amp to perform the same function that my receiver performs (which is DAC and amplification).  Then you had a pop at me with some terminology .

Am I missing something? (This is not sarcastic, and I'm not trying to be rude.  I honestly can't figure out what you're trying to tell me.)

Here's another example I'm fond of (source) which is principally equivalent to both your and my setup despite it being differently arranged:
Sound Card: RME9632
DAC: DCS Elgar Plus
Amp: Linn 2250
Speakers: Dynaudio C2
The system was tuned with a bunch of free software on the internet.  Isn't it awesome how much attention he pays to the listening room? I bet it sounds great.


----------



## FordGT90Concept (Jun 22, 2011)

streetfighter 2 said:


> We were discussing transmission, decoding and DAC of digital audio signals.  You made the claim that people were sending digital signals to their speakers.  I replied that this was inaccurate (with an explanation laden with my standard flair ).


What you hear is always analog (human ears are analog devices).  The only difference between digital and analog in this contex is when the conversion is made--in the computer or somewhere in the speakers/receiver.


----------



## twilyth (Jun 22, 2011)

FordGT90Concept said:


> What you hear is always analog (human ears are analog devices).  The only difference between digital and analog in this contex is when the conversion is made--in the computer or somewhere in the speakers/receiver.


Talk about observing the obvious.

The point is that virtually all music is digital unless you happen to be into vinyl.  Sending a digital signal to a speaker is almost unheard of since it would mean doing the decoding and amplification for each speaker. 

Even sending a line level signal to a speaker is extremely rare for anything but PC speakers and subwoofers.  You get much better sound reproduction with an integrated receiver/amp.  Pick up a copy of any audio magazine or go to any audiophile web site and tell me how many amplified speakers you find. Zero.  There's a reason for that.


----------



## FordGT90Concept (Jun 22, 2011)

This thread is all about stating the obvious, if you haven't noticed.  How the signal goes from sources to speaker doesn't matter as long as the equipment doing it performs an acceptable job for the listener.

HDMI is simpler (one cable for everything) but that doesn't necessarily mean the quality is better (depends on DAC and amplification thereafter).  HDMI also isn't the be-all, end-all in audio transmission--it is simply a well developed standard because the film industry dry humps it all day long.


----------



## twilyth (Jun 22, 2011)

FordGT90Concept said:


> This thread is all about stating the obvious, if you haven't noticed.  How the signal goes from sources to speaker doesn't matter as long as the equipment doing it performs an acceptable job for the listener.
> 
> HDMI is simplier (one cable for everything) but that doesn't necessarily mean the quality is better (depends on DAC and amplication thereafter).  HDMI also isn't the be-all, end-all in audio transmission--it is simply a well developed standard because the film industry dry humps it all day long.


No this thread started out to cover the various ways of getting digital audio data to your AV system.  And if you had bothered to read the first half dozen posts or so you would realize that HDMI is by far superior for anything more than 2 channel stereo sound.  It can handle 8 channels of 24 bit encoded audio with bit rates up to at least 192kbps.  Show me which other digital specification lets you do that.

I'll wait.

Edit:  as a side note, this only came up because I wasn't able to run the output from my 5850 through my receiver - or so I thought.  So there was a whole predecessor thread that dealt with other ways of getting the digital signal to my receiver.  I wanted to go digital since I was getting some annoying hum using the analog audio output.  Also, I wasn't too concerned with having more than 2 channels since it was only for tv and since my receiver would simulate 7.1 surround from the stereo signal anyway.


----------



## streetfighter 2 (Jun 22, 2011)

FordGT90Concept said:


> This thread is all about stating the obvious, if you haven't noticed.  How the signal goes from sources to speaker doesn't matter as long as the equipment doing it performs an acceptable job for the listener.
> 
> HDMI is simpler (one cable for everything) but that doesn't necessarily mean the quality is better (depends on *the input track,* DAC and amplification thereafter).  HDMI also isn't the be-all, end-all in audio transmission--it is simply a well developed standard because the film industry dry humps it all day long.


This is the first post in this thread you've written that makes perfect sense to me (with some editing of course).  What appears obvious to you may not be so obvious to people who don't know about digital audio, Mr. Smarty Pants.   


twilyth said:


> HDMI is by far superior for anything more than 2 channel stereo sound *PCM (for lack of competition)*.


FTFY


FordGT90Concept said:


> The primary reason to avoid HDMI is HDCP.


How do you watch your blu-rays without being downgraded to DTS/AC3 core?  Last I checked DisplayPort has HDCP too (and DPCP) . . .

Also I covered what you're talking about with SPDIF in the fifth post in this thread.  It's nice to hear someone else say it though .


FordGT90Concept said:


> HDMI is not special in regards to, well, anything--except being beloved by Hollywood.


That makes it pretty fucking special though.  I don't have DisplayPort on any of my HDTVs or receivers.  Do you?


----------



## FordGT90Concept (Jun 22, 2011)

DisplayPort - anything HDMI can do, DisplayPort can do better.  DisplayPort, however, isn't likely to get much backing until resolutions greater than 1080p are offered.  And by then, I would not be surprised at all if some fiber optic universal cable system comes of age replacing DisplayPort.

But seriously, any digital signal that has enough bandwidth can do everything HDMI does.  HDMI is not special in regards to, well, anything--except being beloved by Hollywood.  Optical S/PDIF could easily exceed what HDMI can do in terms of audio if the standard were expanded to allow it (which it won't because they already have HDMI).

Typical audio outs include:
-3.5mm S/PDIF
-coaxial S/PDIF
-optical S/PDIF
-3.5mm analog: L/R, rear L/R, side L/R, sub/center
-HDMI w/ audio pass thru or integrated audio device

The primary reason to avoid HDMI is HDCP.


----------



## FordGT90Concept (Jun 22, 2011)

streetfighter 2 said:


> How do you watch your blu-rays without being downgraded to DTS/AC3 core?


Never seen a movie on BluRay and I don't plan to any time soon.




streetfighter 2 said:


> Last I checked DisplayPort has HDCP too (and DPCP) . . .


I didn't say I liked DisplayPort . . .


----------



## twilyth (Jun 22, 2011)

FordGT90Concept said:


> DisplayPort - anything HDMI can do, DisplayPort can do better.  DisplayPort, however, isn't likely to get much backing until resolutions greater than 1080p are offered.  And by then, I would not be surprised at all if some fiber optic universal cable system comes of age replacing DisplayPort.
> 
> But seriously, any digital signal that has enough bandwidth can do everything HDMI does.  HDMI is not special in regards to, well, anything--except being beloved by Hollywood.  Optical S/PDIF could easily exceed what HDMI can do in terms of audio if the standard were expanded to allow it (which it won't because they already have HDMI).
> 
> ...



I guess I should have specified that we're only interested in transmission standards that one can actually use.  And since any use of a display port invariably means buying a dp to hdmi adapter, I'm afraid that doesn't count.

As for the other methods, the fact that they "COULD" provide a better signal than HDMI is irrelevant to the question of what is better RIGHT NOW.  But I can appreciate your wanting to backpedal on what was an obvious error.

As for your listing of the various output methods, was that actually intended to be helpful and non-obvious?


----------



## BumbleBee (Jun 22, 2011)

streetfighter 2 said:


> That makes it pretty fucking special though.  I don't have DisplayPort on any of my HDTVs or receivers.  Do you?



I like your logic lol


----------



## streetfighter 2 (Jun 22, 2011)

FordGT90Concept said:


> Never seen a movie on BluRay and I don't plan to any time soon.


I'm getting the feeling, like getting hit in the foot by a sledgehammer, that you really don't like HDMI.  Unfortunately in the discussion of digital audio it's rather important to mention HDMI because it's widely accepted and is currently the ONLY way to play DTS-HD and Dolby TrueHD tracks (other than DisplayPort which exists in Atlantis and during the night on Alpha Centauri).


BumbleBee said:


> I like your logic lol


----------



## Frick (Jun 22, 2011)

Why isn't this in the Audio forum?

Also I don't like HDMI. Weak connectors.



FordGT90Concept said:


> Never seen a movie on BluRay and I don't plan to any time soon.



It's actually a treat if done right.


----------



## BumbleBee (Jun 22, 2011)

yeah HDMI needs a locking mechanism for heavy gauges.


----------



## Irish_PXzyan (Jun 22, 2011)

BumbleBee said:


> Yamaha.



Thank you


----------



## qubit (Jun 22, 2011)

Thanks twilyth, that was a lot of useful info about HDMI.

I guess it's 'obvious' that HDMI would be better than spdif, because it's a much newer standard. I say 'obvious', because newer isn't always better.  I'm thinking about such things as MP3 downloads over CD and heavily compressed digital TV over a good quality, undistorted analog signal, where the older standards were better.


----------



## Ra97oR (Jun 22, 2011)

FordGT90Concept said:


> First, which lossy compression was used nor its bitrate have anything to do with digital vs analog.  If your source is crap, it's gonna be crap no matter what.
> 
> Second, that "test" is BS because both "clips" are the same:
> 
> ...



Next time try downloading both files and have a listen or just use a simple DBT plugin on foobar.

The thing is, if you are arguing about CD 16bit to 24bit, that massive difference from 128kbps MP3 to 320kbps MP3 should be outright obvious to you. 

I have already stated that most high-end and professional DACs do not accept HDMI, they tend to work on RCA, BNC and Optical cables as a medium. It really depends on the appication, HDMI is not better, it is simply another option to choose from.


----------



## slyfox2151 (Jun 22, 2011)

how to play HD-DTS without a DTS-HD receiver?


thats easy, just convert it to lossless wav (LPCM) on the fly with total theater.
(its lossless so yes its exacly the same as if it was decoded directly from the receiver.)

play HD-DTS without HDCP? easy, just use AnyDVD HD, removes all protection from a blu ray.
http://www.slysoft.com/en/anydvdhd.html

*Allows you to watch movies over a digital display connection, without HDCP-compliant graphics card and without HDCP-compliant display.


(inb4 someone says something about the fact its not free / is too expensive, completely missing the point of this post and the fact that if you can afford a high end system that can make use of such high quality sound then you should be able to afford this software.)





NOTE* afaik anything i linked is not illegal.


----------



## Thatguy (Jun 22, 2011)

FordGT90Concept said:


> DisplayPort - anything HDMI can do, DisplayPort can do better.  DisplayPort, however, isn't likely to get much backing until resolutions greater than 1080p are offered.  And by then, I would not be surprised at all if some fiber optic universal cable system comes of age replacing DisplayPort.
> 
> But seriously, any digital signal that has enough bandwidth can do everything HDMI does.  HDMI is not special in regards to, well, anything--except being beloved by Hollywood.  Optical S/PDIF could easily exceed what HDMI can do in terms of audio if the standard were expanded to allow it (which it won't because they already have HDMI).
> 
> ...



   Display port already offers more bandwidth then HDMI.


----------



## cheesy999 (Jun 22, 2011)

Thatguy said:


> Display port already offers more bandwidth then HDMI.



you don't need it for current Video and Audio Formats


----------



## twilyth (Jun 22, 2011)

Thatguy said:


> Display port already offers more bandwidth then HDMI.



As far as audio is concerned, they seem to be identical.



> Optional 8-channel audio with sampling rates up to 24 bit 192 kHz, supports encapsulation of audio compression formats


----------



## Thatguy (Jun 23, 2011)

twilyth said:


> As far as audio is concerned, they seem to be identical.



display port supports upto 2560x1800 resolutions on a single monitor and even large daisy chanied resolutions. Display port also have no lisencing costs either IIRC. Its all gonna go display port sooner or later, but hollywood may fight it becuase IIRC it does not offer HDCP "which is fine by me"


----------



## qubit (Jun 23, 2011)

Thatguy said:


> display port supports upto 2560x1800 resolutions on a single monitor and even large daisy chanied resolutions. Display port also have no lisencing costs either IIRC. *Its all gonna go display port sooner or later, but hollywood may fight it becuase IIRC it does not offer HDCP "which is fine by me"*



You bet they're gonna fight it.  Unfortunately, the media cartels are so damned powerful, that they can easily defeat the introduction of technologies that don't feature draconian DRM restrictions to satisfy them. They've done it several times over now and is why HDCP exists on HDMI. Therefore, I wouldn't bank on Display Port taking over.


----------



## Thatguy (Jun 23, 2011)

qubit said:


> You bet they're gonna fight it.  Unfortunately, the media cartels are so damned powerful, that they can easily defeat the introduction of technologies that don't feature draconian DRM restrictions to satisfy them. They've done it several times over now and is why HDCP exists on HDMI. Therefore, I wouldn't bank on Display Port taking over.



   I don't think they get a choice when display port implementations are free and HDMI costs money.


----------



## FordGT90Concept (Jun 23, 2011)

DisplayPort does support HDCP (and DPCP) and the standard itself is royalty free (unlike HDMI) but HDCP still requires its licence fees.

HDMI was created by Hitachi, Matsushita Electric Industrial (Panasonic/National/Quasar), Philips, Silicon Image, *Sony*, Thomson (RCA) and Toshiba with the support of Fox, Universal, Warner Bros., Disney, DirecTV, EchoStar, and CableLabs.

DisplayPort was created by VESA (the same group that brought you the 4:3 and 8:5 ratio standards) and is used/supported by the computer industry exclusively.  HDMI is simply inadequate for the ridiciously resolutions monitors are reaching (e.g. 3840x2160 @ 60 Hz) so DisplayPort is there to answer the call.

HDMI = 8.16 Gb/s
DisplayPort = 17.28 Gb/s


----------



## Widjaja (Jun 23, 2011)

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 (Jun 23, 2011)

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


----------



## Widjaja (Jun 23, 2011)

FordGT90Concept said:


> 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 (Jun 23, 2011)

Frick said:


> 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 (Jun 23, 2011)

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 (Jun 23, 2011)

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 (Jun 23, 2011)

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


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## slyfox2151 (Jun 23, 2011)

Funtoss said:


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



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


nothing.


----------



## streetfighter 2 (Jun 23, 2011)

Easy Rhino said:


> 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.*
> ...


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 (Jun 23, 2011)

Easy Rhino said:


> 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 (Jun 23, 2011)

streetfighter 2 said:


> 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. 



slyfox2151 said:


> 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 (Jun 23, 2011)

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 (Jun 23, 2011)

LAN_deRf_HA said:


> 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 (Jun 23, 2011)

LAN_deRf_HA said:


> 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 said:


> 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 (Jun 24, 2011)

Easy Rhino said:


> 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 (Jun 24, 2011)

Widjaja said:


> 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 (Jun 24, 2011)

needs more thunderbolt to replace all connectors


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## Wrigleyvillain (Jun 24, 2011)

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


----------



## LAN_deRf_HA (Jun 24, 2011)

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 (Jun 24, 2011)

Wrigleyvillain said:


> 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.


LAN_deRf_HA said:


> 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 (Jun 24, 2011)

a beautiful sight


----------



## streetfighter 2 (Jun 25, 2011)

twilyth said:


> 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 (Jun 25, 2011)

streetfighter 2 said:


> 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 (Jun 25, 2011)

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.​


twilyth said:


> 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.).


twilyth said:


> 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.


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## Thatguy (Jul 16, 2011)

Easy Rhino said:


> 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 ?


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## Dent1 (Jul 16, 2011)

A few years back I watched Max Payne the movie in DTS-HD Masters downscaled to regular DTS, due to receiver limitations. The sound quality and positional effects were much better than any "normal" DTS soundtrack i've heard on a movie.


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