New LG Smart TV. Audio dropouts via HDMI

Well I borrowed my brothers Samsung soundbar today and connected it directly to the Humax.. muting the TV.

HD channel. Everything fine for 20 mins.. then sound cut out on the soundbar. But instead of the 1 sec drop on the TV sound, the cutout was for 10 secs.. then when it came back it was cutting in and out all the time. Really bad.
Switched to the other HD channels didn't solve it. Switched to an SD channel and the sound seemed to come back OK. Switched back to HD... constant cutouts again.
Only fixed by switching the Humax off and on again.

Baffled now. Deffo seems to be a box problem though not a TV one :(
 
Was the connection with a fibre optic (Toslink) cable? Per my previous post, I have both my Humax boxes connected with these, a bit early yet with just a couple of hours running, there have been no drop outs. Proves nothing , I suppose, except that it's perhaps a HDMI problem. I'll continue to use the Humax's with my amp and Toslink connections for a while and let you know how it goes.....I don't consider this a fix, I would rather not run my surround amp permanently when using the Humax's. When properly set up, the LG TV sound is adequate for everyday use.

Incidentally, I first came across optical connections six or seven years ago when I purchased my first surround sound system, a cheapie Yamaha. Initially, the Yamaha amp was connected with the old coloured audio cables. Not expecting much, I purchased a Toslink cable and plugged it in.........Wow! What a difference! Much, much improved sound and surround effect....I've never used the old cables since.

Gerry
 
Well I borrowed my brothers Samsung soundbar today and connected it directly to the Humax.. muting the TV.

HD channel. Everything fine for 20 mins.. then sound cut out on the soundbar. But instead of the 1 sec drop on the TV sound, the cutout was for 10 secs.. then when it came back it was cutting in and out all the time. Really bad.
Switched to the other HD channels didn't solve it. Switched to an SD channel and the sound seemed to come back OK. Switched back to HD... constant cutouts again.
Only fixed by switching the Humax off and on again.

Baffled now. Deffo seems to be a box problem though not a TV one :(

Guessing it's an issue with the TV/sound bar ac3 decoding. In the box TV setup menu try changing the digital audio out to stereo.
 
As per my other post, your AV amp handles ac3 audio correctly, your TV does not. Force the box to output to mp2 stereo by changing the digital audio out in the TV setup menu to stereo. The SPDIF (toslink optical and coax) digital audio out and HDMI audio out produces identical digital audio which for SD source is mpeg1 layer2 and for HD (unless forced to stereo) is sourced as AAC 2.0 or 5.1 and decoded to Dolby Digital (aka AC3) 2.0 or 5.1.
 
Last edited:
As per my other post, your AV amp handles ac3 audio correctly, your TV does not. Force the box to output to mp2 stereo by changing the digital audio out in the TV setup menu to stereo. The SPDIF (toslink optical and coax) digital audio out and HDMI audio out produces identical digital audio which for SD source is mpeg1 layer2 and for HD (unless forced to stereo) is sourced as AAC 2.0 or 5.1 and decoded to Dolby Digital (aka AC3) 2.0 or 5.1.
In my case I am experiencing the sound drop outs when watching SD programmes and recordings (I rarely use HD) so problems with handling ac3 are unlikely to be the source of the problems in my case
 
In my case I am experiencing the sound drop outs when watching SD programmes and recordings (I rarely use HD) so problems with handling ac3 are unlikely to be the source of the problems in my case

Push in the hdmi cable firmly, try a different hdmi cable and/or socket on the TV. Try a analogue connection to the TV. If you don't get dropouts with toslink and do with hdmi it's likely to be a dodgy connection. Have you anything else as a HDMI audio source you can try with the existing HDMI cable ?
 
Guessing it's an issue with the TV/sound bar ac3 decoding. In the box TV setup menu try changing the digital audio out to stereo.


It is set to Stereo

Soundbar is plugged directly into Humax via Toslink. Not through TV.


Tried again from scratch tonight. Recorded programme this time (this morning was LiveTV).
Same again. After about 20min... the time when via HDMI I'd get a 1 sec dropout... the Soundbar lost audio for about 7-8secs then came back and was in/out of dropouts constantly every few secs from then on.

So it seems (to me) to be an audio fault on the Humax ??
 
It is set to Stereo

Soundbar is plugged directly into Humax via Toslink. Not through TV.


Tried again from scratch tonight. Recorded programme this time (this morning was LiveTV).
Same again. After about 20min... the time when via HDMI I'd get a 1 sec dropout... the Soundbar lost audio for about 7-8secs then came back and was in/out of dropouts constantly every few secs from then on.

So it seems (to me) to be an audio fault on the Humax ??

If it is it's not an issue I have seen posted before. I have two boxes with no audio issues using both toslink (feeds a Sony Cordless Surround Headphones via a toslink matrix switch) and HDMI to a Yamaha AV receiver.
 
Four hours recorded programmes plus live TV played through both my T2's connected with Toslink's and no drop outs.

The toslink has the same audio output derived from the same decoder as the HDMI digital audio out so unlikely to be a box issue. Does the soundbar have HDMI in or just the TV ?
 
I have no hard evidence, but in my opinion these dropouts are the result of HDCP renegotiation.

IIRC, in the early days I was experimenting with both HDMI and the analogue signals, and with the HDMI connected to the TV but not active (because the TV source was the analogue connections), the analogue sound was interrupted repeatedly with an HDMI destination detected that was refusing to complete the handshake.
 
The toslink has the same audio output derived from the same decoder as the HDMI digital audio out so unlikely to be a box issue. Does the soundbar have HDMI in or just the TV ?

Graham.......I'm not sure if your question is for me or 'Philbean'. Mine is a LG surround sound amplifier with just a Toslink connection and I confirm there have been no dropouts so connected. I have now switched the amp off and I am now using the Humax's with their HDMI's connected to the TV. One of the boxes has been running for nearly an hour and there have been just two dropouts.

Gerry.
 
Graham.......I'm not sure if your question is for me or 'Philbean'. Mine is a LG surround sound amplifier with just a Toslink connection and I confirm there have been no dropouts so connected. I have now switched the amp off and I am now using the Humax's with their HDMI's connected to the TV. One of the boxes has been running for nearly an hour and there have been just two dropouts.

Gerry.

Which channel ? There was a period in which BBC1-HD experienced short audio dropouts during Father Brown (which is in 5.1). The problem was broadcaster related as looking at a recording proved it was in the broadcast stream so everyone had the problem. Not experienced any issues with either of my HDR-FOX-T2's. There is however a known issue with loss of HDMI audio on the 1800/2000T boxes.
 
Which channel ? There was a period in which BBC1-HD experienced short audio dropouts during Father Brown (which is in 5.1). The problem was broadcaster related as looking at a recording proved it was in the broadcast stream so everyone had the problem. Not experienced any issues with either of my HDR-FOX-T2's. There is however a known issue with loss of HDMI audio on the 1800/2000T boxes.

The live TV channel was BBC News HD. I really think this is an LG TV problem. It only started for me after the 'upgrade' from our previous Samsung, there was no problem at all with that TV using the HDMI connections on the Humax boxes. As per my previous posts, since April, I've tried various fixes to no avail....It looks as though it's a quirk that us Humax/LG TV users may well have to put up with...Many thanks to all for taking time to reply......'Philbean' I'm sorry I appear to have hijacked your thread..

Gerry
 
I agree that LG (smart) TVs are the common factor, older dumb LG tv's work fine.

The problem affects ALL channels both SD and HD and is not in the broadcast stream because replaying recordings will have drop outs at different points.
Multiple HDMI cables and sockets have been tried to rule out connection problems, other HDMI connected devices don't show the problem

I think Black Hole may be right
I have no hard evidence, but in my opinion these dropouts are the result of HDCP renegotiation.
In which case inserting an HDMI splitter between the boxes might solve the problem according to this page
 
Thats interesting. I thought about a splitter box a few days ago then thought, like the 2.0 cable, it was a silly idea. Might be worth trying now.

I'm approaching a point where I have to decide whether to return the TV or not.

Don't know what to do really.
It is pretty annoying. If there is no 'fix' then I'm not sure I could live with the dropouts longterm.

I'm surprised more users aren't affected though. I thought there'd be a lot of newish LG TVs out there with Hummy users.
 
I used to have an issue with a 'green screen' on my TV when turning on either of my HDR boxes. Not every time though. I haven't had any issues with sound dropouts.
The solution for me was to use an HDMI splitter. It actually serve me well as I use it to connect multiple devices to my TV and as it has two outputs, I pipe one to another room.

The HDMI splitter has optical audio output, I connect that directly to my sound system.

HTH
 
Last edited:
Just to update.

Borrowed a HDMI splitter and it still has the dropouts.
Noticing quite bad backlight banding on the TV now in panning shots (DSE) so its deffo going to be a return. Shame about the issues cos it has a stunning picture.
 
Let me put my head above the parapet and admit I am a member of this club. I had a facepalm moment when I read the first post in the thread as I had ordered an LG 49UJ750V at the end of August but by the time it was delivered I had been hit by an unexpected spike in workload and didn't have time to install it until after this thread started. I also experience the sound drop outs but as a deaf old bugger they probably don't bother me as much as some of the posters. However my technical curiosity led to me experiment with possible solutions. My first stab was to try a cheap unbranded manual HDMI switch which I bought some years ago from an international ebay seller because it was reported to cure some HDMI handshake problems and I thought it was useful to have around. Unfortunately it didn't help the sound drop out problem. So I purchased a 4K HDMI splitter (Tendak AV-126-BK (UK)) from Amazon https://www.amazon.co.uk/dp/B01HLS1X36/ref=pe_3187911_185740111_TE_item and after a couple of days I don't think I have noticed any sound drop outs since installing it. NB please don't rush out and buy one; I will update this thread in a few more days with a longer term report. At the moment I am powering it with the supplied power supply but the next step will be to see if it will work from a power supply from a USB port.

Edit. See post #48 for a disappointing update.,
 
Last edited:
The box I tried looked identical to that except the writing on it was blue not green and it wasn't labelled as a 4K box.
 
Back
Top