HDMI audio.

[T i m]

Hi all,

Earlier I was asked if I could provide a / TV for someone in their bedroom and they wanted their TalkTalk Youview box in there as well.

So we made a small hole though the wall and ran an aerial and Ethernet cable to the area and used a new HDMI cable from the Youview box to a spare 19" TV I took up there for the purpose.

We got picture straight away when we selected the (single) HDMI port but no audio? Enabling the aerial out on the Youview box, running a UHF lead from box to TV and tuning the TV on Freeview gave us sound and vision, as did playing a DVD within the TV itself.

We tried another (new, probably Poundland) HDMI cable but no change. My next test was going to try going SCART from the Youview box to component in on the TV but whilst we had a SCART to phono converter, they didn't have any phono cables. ;-(

The Youview box was working fine on their main TV with the first HDMI cable (I didn't hook it back up again to see if it still did).

I could have tested the SCART in (for audio) on the TV with their DVD player but the TV doesn't have SCART in, or the DVD player HDMI out. ;-(

I couldn't see any setting that may have been relevant for audio in on HDMI on the TV audio out on the Youview box. The was an optical output from the Youview box but we didn't have any matching audio gear.

So, OOI, is it likely we have two HDMI cables that aren't compatible with that Youview <> TV combo or could it be that the audio in on the TV simply doesn't work (I'd not tested that before taking it up there as it had only been used for Freeview before that).

If I can't get round it with a SCART to component solution, we have access to a slightly bigger TV to try, but is it likely to be two HDMI cables, especially if they are only cheapies?

Cheers, T i m

[Bill Wright]

Try the TV set with a different HDMI source. Lack of audio from HDMI is a common weirdness with tellys. Often the answer is to have the HDMI source working and the telly set to receive it, then unplug the HDMI from the telly, take a deep breath, then plug it back in.

Bill

[alan_m]

You will have two volume controls in series. One on the Youview box and one on the TV. You need to set both the TV and box volume for the maxiximum audio level you want and then control it up/down with whichever remote you prefer.

Ensure that the TV or the Youview box is not set to mute.

Some TVs have a menu option for audio. I know of one TV where the option is speaker OR headphone where the latter turns off the TVs speakers irrespective of anything being plugged into the 3.5mm headphone jack (I think this allows a soundbar to be connected where other more sophisticated connection methods are not available)

[Brian Gaff]

Yes this is true, but the thing is one wonders does anybody not test their software for this stupidity before unleashing the sets to an unsuspecting world?

I even find some of the video standard conversion gizmos you get can work intermittently depending on the sequence of plugging in or even of mode selection on the tvs and computers involved. We do seem to have got ourselves into a bit of a muddle. Brian

[Dave Plowman (News)]

Never come across that. I was surprised to find that an HDMI cable to a TV from an after market sound card on a desktop PC had the audio too.

[spuorgelgoog]

Using my Hudl 2 tablet with HDMI, the tablet changes to having only two volume settings (1 and 11) and on the TV I have to set the volume right down before plugging in the tablet.

One would think that line level audio would have a standard ... oh hang on, it did. I wonder why they didn't keep that when moving to digital.

Owain

[whisky-dave]

HDMI isn't just one easy standard, it can be quite complex with the differnt versions that have come and gone.

Check 1/2 way down the wiki page to versions.

[Vir Campestris]

I just looked at that to check my memory wasn't playing tricks...

"Transition-minimized differential signaling (TMDS) on HDMI interleaves video, audio and auxiliary data"

The video and the audio are interleaved. Which means no cable fault could mute the audio, but leave the video OK.

Andy

[Dave Plowman (News)]

It did. Called the EBU standard. (European Broadcasting Union) Peak level was meant to be 10 dB below dBFS. To allow for digital getting nasty if you overmod. It was initially for digital recording (and CDs), but most of the TV channels still stick to it. In the main. But commercial radio - as ever - smash everything round the endstop.

[Dave Plowman (News)]

Are you saying there is a version which carries video, but not audio?

[Roger Hayter]

*Not* a cable version; but versions of transmitters and receivers, definitely. The first Apple whateverport to HDMI adapter I got didn't do audio.

[whisky-dave]

My 2010 Mac mini did not support audio from the HDMI not sure why but I remember looking it up a couple of years ago as it was the first time I thought about using the audio, before that I was happy with the sound the mini had.

[Roger Hayter]

My 2011 Mac does support HDMI audio, but the Thunderflash port to HDMI adapterI bought from Apple didn't! The later model adapter did.

[Steve Walker]

We took an HDMI DVD player with us when we went away at Christmas, we got not sound, so did without. When we got home, we still had no sound. Mysteriously a sound format setting had changed and changing it back restored everything.

We also have a Humax H3 box in the kitchen. Sometimes it comes on with no sound and switching off and on does nothing. Pulling the HDMI lead out and re-inserting it brings the sound back - although sometimes it takes two or three goes.

I think the designers and manufacturers have put too much effort into copy protection and not enough into making it a robust system.

SteveW

[Steve Walker]

DVI is effectively that. You only need a dumb adapter to connect either to the other, but of course you then have to make separate arrangements for the audio.

SteveW

[T i m]

<snip>

Thanks to all those who replied.

I think a few may have hit the nail on the head with the 'it can be very unpredictable' and / or re-set settings and it may make a difference (when it shouldn't).

After trying many different things that night with no better understanding on what was 'wrong' (with the straight HDMI lead solution). Yesterday I added some phono cables to the SCART <> phono adaptor and plugged them into the component inputs on the TV and I only got mono video (tried all the 'video' inputs) and I still don't think I got any audio (I didn't really worry with only mono video)?

Then I switched the input on the TV back to HDMI and 'boom', colour picture and good audio! <shrug>

This wasn't one of those 'let's carry on playing and see if we can find out what it was' situations, it was a 'good, don't touch anything and leave' moment. Time will tell how reliable it all is. ;-)

Cheers, T i m

[Dave Plowman (News)]

Ah - obviously if you do a cludge, anything is possible. I was more thinking of devices normally connected by HDMI as in the OP's case.

[Dave Plowman (News)]

But I thought everything Mac was always perfect? Obviously not, since the HDMI output on an ancient desktop PC I have carries the audio too.

[Dave Plowman (News)]

DVI has the same digital video standard as HDMI, but also makes provision for analogue video. But no provision for audio.

[Dave Plowman (News)]

Did any version of SCART do full component?

YC - (S video) yes. Assuming compatibility at both ends.

SCART was basically composite or RGB. But you can buy convertors. But I don't think any version of SCART allows HD, unlike full components.

My oddity with HDMI was feeding my Humax STB into a two output DA. To feed the kitchen TV as well as the main one. Had to use HDMI to twin CAT5 cables because of the run - too far for HDMI.

Works just fine. But if you select the HDMI input on the kitchen set last, it switches on the subtitles on the Humax. Didn't happen with the previous Humax.