DVI to HDMI adapter audio conundrum?

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nasqualee

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Most video cards with DVI jacks also come with -- one -- DVI to HDMI adapter. So far as I can tell the only difference between the two is that HDMI has audio, and DVI does not.

These adapters I'm sure convert the jack type for the sake of video, but what about audio? If they do audio too then how is it that a DVI plug outputs audio?

If will I have two monitors with speakers and HDMI input, how will the audio get to them?

More specifically, my PC has onboard audio and video to run one monitor and one set of speakers. Onto it I will be inserting a video card in order to drive two monitors (with speakers and ATSC tuners). I'd like to think that the new video card will have two video channels and two audio channels, or at least one audio channel that's split between the two.

Perhaps it's best to use the onboard audio, split it and route it to the two monitors? Are two separate audio channels even possible, or should I ignore the monitor speakers -- for normal PC use -- and use external speakers? I don't know.

How can audio get to two monitors? Thanks for your help.
 

aylafan

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i think you are talking about ATI videocards with an integrated sound chip on the videocard. that is why it can output video and audio on HDMI. i think NVidia videocards can only output video if you use the DVI to HDMI adapter. correct me if i'm wrong.

i believe that DVI and HDMI share the same signal. they just have a different connector. that is why you have a DVI to HDMI adapter.

about the two monitors with speakers? i think you should use external speakers with your onboard audio.

when you insert a videocard. you should disable your onboard video. then connect both monitors to the DVI connectors on the videocard.

also, i don't think videocards are supposed to output audio or have audio channels. that is why there are soundcards out there. unless you are using an ATI videocard (with an integrated sound chip) on HDMI. that is a different case.
 

MrManO1

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Two quick and easy things:

1. Onboard speakers in monitors usually suck pretty bad, externals are usually much better for pretty cheap.
2. Audio can be outputted over DVI as long as it's a newer ATI video card (not NVidia) using PCI-Express

But as far as the dual DVI->HDMI Adapters carrying audio and video - that sounds quite interesting and have no idea.
 

dorian11

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I've been trying to figure out if ATI's adapter is special... I can't get audio over HDMI with a generic DVI to ADMI adapter cable (ATI 4850), though I haven't ruled out all other potential problems... only thing is, there aren't data channels specific to audio on the HDMI connection, so I can't see how this would be so. There is, however, an I2C bus and some CEC channel that are on HDMI and not DVI, so maybe without the special adapter the two devices can't talk and get properly configured...
 

boeing1234567

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First of all there are nV cards that will do HDMI Audio via DVI adapters, but they are rare with a SPDIF passthrough that runs back into the card from the external audio card/source and will only support up to 5.1 audio (SPDIF limitation), while the HD4K does 7.1.

Second, yes AMD and nV use special adapters that use some of the additional pins to send data for the audio channel, they are different than the standard adapters.

Lastly, I would suggest just do the one HDMI->DVI conversion and hook up the monitors separately, the monoprice splitter means you can only clone the displays not span (have two separate desktops).
 

boeing1234567

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Thanks TheGreatGrapeApe! I didn't realize that the splitter can only create clones, not spanning the desktop space. This make a huge difference. Cheers.
 

boeing1234567

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For output from HDMI (Video Card) to DVI (LCD), does it make a difference if I use an (HDMI/DVI adapter + DVI cable) or a (HDMI/DVI cable) like the one they sell on http://www.dealextreme.com/details.dx/sku.2703?
 
I would say no. Technicially it's an additional interfaces conection, so like any connection, there's potential for oxidization or dirty or even the bazillionth of a fraction (exageration) difference in different metal to different metal contact conduction at the adapter points, but overall both should provide an equally good picture.

I tend to use single solutoins for one main reason other than that terrible bazillion of a fraction problem ;) and that's because I LOSE little tiny dongley things like that when I do things like plug/unplug, etc.

But if you're connecting it once and never really touching it much again other than to deal with just one end, then even that's not much of an issue.
 

lee67

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Could you please specify which nV cards you think can output HDMI Audio via DVI adapters? I had to replace a noisy fan nV 9500GS, which has HDMI output connector on the board with audio, with an EVGA 9500GT which has two dual DVI connectors on card. EVGA says it is HDCP certified and provides an audio-pass through white 2 pin connector internally on card for pass through from motherboard like used with old card. What I would need to know is, what and whose DVD to HDMI adapter plug would I need to buy or even if this board can do audio over HDMI (using adapter DVI to HDMI)? I am still waiting for a reply from EVGA on this question. Seeing your above statement gave me some hope that there might be some kind of solution. TIA
 
Everyone, STOP!

DVI and HDMI are electronically compatable, but only HDMI can carry audio. DVI CAN NOT CARRY AUDIO SIGNALS, PERIOD!

ATI cards and some NVIDIA cards feature an HDMI IN that will take a HDMI audio signal (either directly with ATI, or with an internal SPDIF cable that connects to the motherboard with NVIDIA). So theoretically, you can take a HDMI signal, decode the audio portion, and output the video to a moniter using DVI. The audio signal, however, will be handled internally and is not re-transmitted.

Also, there should be zero compatability issues using a HDMI->DVI/DVI->HDMI adaptor, as for video, they are the exact same signal, just a diffrent port. You can get some signal degregation due to the adaptor itself though...
 

Euphoria_MK

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On a single HDTV my hd4870 works great. I am using the DVI to HDMI converter and I get the sound and the video through one cable. You just have to go into the sound card properties and enable SPDIF.

I am not sure though about using the Dual Monitor ... I dont know if the sound is ported through both of the DVI ports on the card....?
 


Spdif is carried on another cable, and carries only an audio signal. Your sound is being routed from elsewhere, not over DVI, especially if it takes a Spdif option to get the signal to go.

I know the 4000 series does something with audio and HDMI, but i'm not fimmiliar with how it works. I can tell you, the audio signal is not comming past the DVI converter.

http://en.wikipedia.org/wiki/Digital_Visual_Interface

Unlike HDMI, DVI usually carries no audio data
 

Euphoria_MK

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Read the ATI documentation, I think they use the middle wires to transfer audio, compare the DVI to HDMI adapter from the NVIDIA cards to the DVi to HDMI adapter from the HD4870, and you'll see the difference.

I dont have any other cable connected to my HDTV except the HDMI cable.

This is only done on ATI 4870 and I think 4850 cards, and thus does not follow the official DVI standard that is implemented on other cards or media products.

EDIT:

Also in the quote you wrote, it says that DVI "usually" does not carry audio, but that does not mean that it can not carry the audio signal.


Cheers
 

dodugeo

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We cannot just say it wont, by standards it should not . Basically Standards are made to make components compatible with other products. Here, thats not the case. Here ATI did some connection modifications to work that way, it wont reduces the bandwidth either...You can also just cut a DVI cable and use it for your own custom audio project...it just a matter of connection. It's a pinout issue. ATI has done some custom mapping of their DVI port to support a dvi-hdmi connection that carries audio. The only thing you need is custom adapter from ATI too inorder to understand what goes where. An ordinary DVI HDMI adapter may not work.

 
The question then becomes this:

If you do HDMI->DVI, even if you find a way to carry the audio singal over a DVI connection, how does the input device interpret that signal. That's the other point you are all ignoring; Even if you can find a way to carry an audio signal over a DVI connection, how does the input device seperate an audio signal that is not supposed to exist? This is especially important, given the way DVI inputs are used on most moniters...
 

Euphoria_MK

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Simple if the device is not made to accept audio signal then it wont do anything to it.

Where does it say that Audio signal is not suppose to exist? It says that DVI "usually" does not contain audio signal, but that does not mean that it can not be included under a DVI connection.

Usually != Never
 


Then perhaps you should keep that ignorance to yourself and stop posting ! [:thegreatgrapeape:6]

Seriously, why are you contributing to this thread if you admit you aren't 'fimmiliar' with how it works? [:thegreatgrapeape:2]

I can tell you, the audio signal is not comming past the DVI converter.
I can tell you it is. So can many others who have either ATi or nV cards that use the data pins to send audio data to the DVI connector to be converted to HDMI by an adapter, it needs to be specific adapters but it's DVI. How do you think you get 5.1 audio on the HD2/3K and 7.1 on the HD4K ATi cards through their HDMI dongle, they're not connected to anything other than the DVI port. [:thegreatgrapeape:5]

nVidia does the same with SOME of their cards, using the SPDIF input to combine with video to send out the DVI port on their own method of inserting it in between the video signal, which can require a proprietary connector as well, but can someitmes use generic DVI-HDMI adapters. Most GTX 285 cards I've seen ship with the pass-through option, like the XFX model reviewed here at launch which mentions it at the bottom of the first page of the review;
http://www.tomshardware.com/reviews/geforce-gtx-285,2139.html

The nV cards offer the SPDIF pass-through, the ATi cards offer internal pass-through with the SPDIF mode being an option, but they also provide the protected path option which allows for additional audio support including DTS-HD & Dolby Tru HD on the HD4K series. Although they are limited to one audio out path at a time.

Next time don't spoil threads by undoing the constructive posts that precede your uninformed nonsense.
 


You MIGHT need to use the one specific to EVGA's setup. Unfortunately not all of them are made the same it seems, since some people have tried a Zotac (one of the first that had coax and toslink pass-throughs as well) adapters on other models and they don't work. I've seen a bunch of people have issues (and about as many try a generic adapter on an ATi card) on the AVS forum trying to find compatible adapters for a card that's rarer in their market/region.

Some of them can use any DVI->HDMI adapter others require specific connectors. However unlike the ATi it's not a 100% requirement, because they send the signal differently.
 

Junkmailsucks

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Of course DVI can transmit audio. HDMI and DVI are the have the same configurations.
I am using a dvi to hdmi cable (3 meters) out to my 55inch plasma with full digital audio & 1080p output.
I then output from the TV to my receiver and viola 7.1 surround sound AC3 and DTS.

On another machine (Zotac ION) I am attempting to figure out how to disable the audio from the DVI because it is interfering with my optical output to another device.



 

jmsnyc

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I just purchased a Zotac GeForce 9500GT. It has two dvi ports and another port that connects to an adapter for s-video and component video. It comes with the SPDIF cable to connect from the motherboard to the sound card. It is clear there is no sound out through the s-video or component but I would assume that the reason for including the SPDIF cable is to pipe the sound through the DVI port into the Zotac branded HDMI adapter. I dont have it setup yet but I will post back when I do.

By the way, on the box it says "DVI Audio"
 
G

Guest

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I'm having the same problem with no audio from my dvi/hdmi adapter. But I recently found out that there is in fact a special dvi to hdmi with audio adapter.

The problem is, not all graphic cards ship with them. Mainly the cards bought in stores. But if you search the net, like tigerdirect.com, they tell you in the specs which cards include the adapter.

I have a radeon 4650 made by HIS, and this is the info I got from there website. And this is the crazy part. It list the product code for the special dvi to hdmi with audio adapter, but it doesn't include it. It includes a useless dvi to vga adapter???

I guess they want us to buy it. But in any case, there is a special adapter needed, and the product code is below for the part if you want to buy it, but it doesn't list the price. I guess you have to call to find out

http://www.hisdigital.com/un/product2-52.shtml

•Built-in HDMI with 7.1 surround sound support
◦The HIS DVI to HDMI Adapter for ATI 4000/ 3000 series (Product Code: HHDMI4071) is required to fully utilize the audio through HDMI features
•Support for the ATI RadeonTM DVI to HDMI adapter

ACCESSORIES
SOFTWARE BUNDLED
•Driver Disc

CABLE/ADAPTOR BUNDLED
•DVI to VGA adapter
 
G

Guest

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Sorry, I spoke too soon. I just did some more searching, and this is what I found on Visontek website. They are one of they main companies that claim audio through dvi.

If this part doesn't work, than the whole audio through dvi is one of the hughes scams ever

http://www.visiontek.com/store/catalog/product_info.php?cPath=52&products_id=175

DVI to HDMI Adapter - HD3000/4000 series
[PN.400405] $9.99

ATI DVI to HDMI adapter. This adapter will enable HDMI audio/video through the DVI output of the Radeon HD 3000/4000 series PCI-Express boards.
> This adapter is NOT compatible with the HD2000 Series video cards.
 

gtr1000

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Twelve months ago I bought a 25 metre HDMI cable for computer out to lounge 48" HDTV to test run full size of Edius Editing work. Fitted (yellow) HDMI Adapter(Supplied) to Yellow DVI on Asus 9600GT hdmi card.
No sound---- so into forums---no useful answers----only opinions. I had the Audio link from my Asus P5Q Pro Mob connected. Still nothing. Noticed in data that MOB plug out reffered to as SPDIF/HDMI ! H'mmmmm......
Entered Bios, found SPDIF selected, changed to HDMI. Now HDMI appeared back in Sound Card (onboard) properties . Good. Reconnected, rebooted, ------- nice sound at TV! I'm told reversing jumper to card 2 pin also counts but not checked this yet. I specify 5.1 sound for my DVDs--- fine on most TVs(Stereo) but may yet offer alternative 7.1 audio track for the odd client who has some fancy Home Theatre rig.
One other thing---my 5D Mk11 Canon goes intermittent on cheap 2 mt mini to full HDMI cable but perfect on "expensive". Damn !
Cheers Eric NZ
 
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