onthequiet
1 Copper

Re: U2713H No Sound from Audio Out

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Hi Chris,

Two new points to consider:

Point 1:

I have just run a test:

Macbook->HDMI cable->Samsung Television (UE40EH5000).

I am watching a film on on the Macbook and can confirm that sound is being transmitted through the HDMI cable to TV. The only setting  I needed to change on the Macbook was

*Set HDMI  as the output in the system preferences->sound

I also did this with the monitor connected up but no sound. So, it is really strange that sound is being output to the HDMI cable and yet the U2713h is not outputting it through its line-out.

Point 2:

I have purchased the U2713h as a new item (opened box) on eBay. It is brand new / mint  REV A00 with a warranty running from Jan 2013. Anyhow, it clearly stated on the eBay ad that the Dell mDP-DP cable was missing. So, I am not using the official Dell cable. I bought this one instead:

www.amazon.co.uk/.../ref=cm_cr_pr_product_top

If you think this could be the problem, then I am wondering if it is possible for me to obtain the genuine Dell cable somehow?

Point 1 concerns me a little though. I know the Macbook is now outputting sound through the HDMI... that's for sure. For the first time I'm wondering if there is a hardware fault on the U2713h line-out. BUT... cables can be strange and I am wondering also if the U2713h is not 100% happy with the cables (hdmi and mDP-DP) that I am using? I thought HDMI was a standard though... how can it work with the Samsung and not your monitor?

Thanks,

/Brian

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skylarking
3 Zinc

Re: U2713H No Sound from Audio Out

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Brian, in principle a mDP-DP cable should be OK and would not likely be the problem (though these cables were not indicated as included in the packaging according to the users guide).

According to wikipedia, DP (and thus mDP by extension) can support 8 channels of 24 bit 192 kHz uncompressed PCM audio which can encapsulate compressed audio formats in the audio stream. So the question is what type of compressed audio can the U2713 decode, if any? What is rather annoying with Dell is their lack of accurate specification sheets for their products. They seem to be more like sales blurbs that specifications of a products actual capability as i have not found any information on supported audio formats!

Anyway, in my case, my 2x U2711's are connected via DP and the monitor menu <Audio Settings> <Audio Configuration> is set to <2.0> (stereo) rather than <5.1> which is the only other option. The AX510 sound bar power lead is plugged into the "2. DC power connector for Dell soundbar" on the 2nd monitor and the AX510 soundbar audio lead is plugged into the "5. Audio out front" on the 2nd monitor (connector 2. & 5. relate to the connector numbers as defined in the U2711 user guide). My HP Workstation's default audio playback device is set to "Dell U2711-2" (my second monitor plugged into secondary DP port of the graphics card). The default audio playback device properties are configured as Stereo and reflected as 16bit, 48000Hz (DVD quality) in the properties advanced tab. 

So, i have a soundbar which supports stereo, the monitor is set to stereo and the computer is set to stereo and thus all complex compressed formats are decoded to stereo my PC before sending the signal along the DP cable :). How you might do this on the Mac, I have no idea as i don't have a Mac.

Note that in the case of your U2713, there seems to only be the one audio out connector, indicated as connector 7 in the user guide which provides for only stereo speakers to be connected. In my case, the U2711 has front, rear and sub/center audio out connectors on the underside of my U2711 so 5.1 speaker setup can be connected. This has no relation to what audio format can be decoded by the monitor internals, presumably mine can decode DD and possibly DTS.

Chris, maybe you can answer the question of which audio formats the U2713 and U2711 supports over HDMI and DP (and thus what formats can be decode from the audio stream presented to the monitor and finally sent out to the soundbar as stereo)?

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onthequiet
1 Copper

Re: U2713H No Sound from Audio Out

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Skylarking,

Thanks for taking the time out to reply.

The mDP->DP cable was included with this monitor: See the "What's in the box section:

<ADMIN NOTE: Broken link has been removed from this post by Dell>

The guy I bought it from also informed me the original mDP to DP was missing.

I did have a look for audio settings on the monitor's settings, however, there do not seem to be any such settings in the U2713h. The following review shows screenshots of all the menus and these match mine (It will just save me taking screenshots of all the menus) http://www.tftcentral.co.uk/reviews/dell_u2713h.htm

I'm pretty certain the Macbook Pro Retina's default setting (I bought it new from Apple and certainly didn't change it from default) is to output sound in stereo. See the following but there are many more examples: discussions.apple.com/.../4450049  . I will follow up and confirm that this is set to stereo.

To your point about an accurate specification of what type of audio is supported. If there is a specific type of stereo codec that is supported, then it would be good to know what this is for sure! I would have thought the monitor was just taking a stereo input signal and passing that straight to the line-out!

Chris?

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Moderator
Moderator

Re: U2713H No Sound from Audio Out

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* Using the Dell supplied DP to mDP cable, we connected the mDP to the laptop and the DP to the U2713H. You could also go DP to the laptop and mDP to the U2713H
* We then connected the USB Upstream cable from the U2713H to the laptop USB port
* We then connected external speakers to the the U2713H green Audio out jack
* We then opened the Sound control panel, clicked Dell U2713H and then clicked Set Default-Apply-OK. A green arrow appeared on it and the sound worked

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skylarking
3 Zinc

Re: U2713H No Sound from Audio Out

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Brian,seems different regions may have different inclusions in the box. The U2713 user guide i have a copy of did not reference any DP (or mDP) cable [:?]

As for my post, i don't know what happened to the DP wiki link which i thought i added but the link does state that an audio signal is optional (1–8 channels, 16 or 24-bit linear PCM; 32 to 192 KHz sampling rate; maximum bitrate 49,152 kbit/s) and can encapsulate compressed audio formats in the audio stream. I guess this means that the linear PCM data can contain compressed audio and that the receiving device must be able to decode the compressed format. The DP spec says nothing about what the compressed format can be.

2 channel linear PCM (LPCM) is commonly known as stereo. There are no specific types of stereo though different sampling audio bit depths (16 or 24bits) and sampling rates (44.1 or 48Khz) are commonly used by CD or DVD. The real complexity is when compressed formats are disguised as LPCM. 

And Dell says nothing about what stereo audio bit depths/sampling rates are supported and what compressed formats can be decoded from disguised LPCM streams by a U2711 or U2713 !

What may be of interest to you is that the mDP wiki states the following: While the DisplayPort specification is capable of supporting digital audio, the older 2009 line of MacBooks and MacBook Pros are unable to provide an audio signal through the Mini DisplayPort, and only do so over USB, Firewire, or the audio line out port instead (the April 2010 line of MacBook Pro, and late-2009 iMac and later, however, supports this)

So it may be that your issue is not because of any problem with the U2713 but with your Apple laptop if pre-2009(ish).

Still, Dell must resolve the serious lack of detailed specifications of their products.

Chris, please feed back to management that their needs to be much more detail within the specification sheets for their products. And if you can test the U2713 capabilities further, please test some different audio formats sent by the PC to the monitor and report back the results.

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onthequiet
1 Copper

Re: U2713H No Sound from Audio Out

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Thanks Skylarking,

Yes I have the newer Macbook Pro Retina (Mid 2012) and it supports audio out to the mDP:

support.apple.com/.../HT4241

It seems my mDP supports audio out also as this reviewer is implying:

www.amazon.co.uk/.../ref=cm_srch_q_rtr

My stereo speakers have been tested working and are plugged directly into the U2713H line out

So I am really at a loss as to what is wrong. I keep reading again and again that the only thing I need to set on the Mac is the audio out the Dell monitor and I have done that.

You seem to have a good technical knowledge on the specs and so on.. I don't really know a lot about that side of things other than the Mac supplies multichannel audio (up to 8 channels) and video signals over Mini DisplayPort and it would seem the display port carries the audio.

I have asked Chris if he can get hold of a cable for me so I can try that but other than that... I'm stuck

Thanks,

Brian

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onthequiet
1 Copper

Re: U2713H No Sound from Audio Out

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Problem solved. A faulty line-out port!