I am using an HDMI cable from my Comcast HD cable box to my LG LCD 1080P TV and am getting sound lag on certain channels. Could this be the HDMI cable? The cable box? My TV?

If it's just certain channels it sure sounds like a problem with your cable system and/or cable box. Everything fine with other HDMI sources?

I do not think it is the cable box because if I run normal red and white audio cables from the cable box to some speakers there is no delay. Since I have sound running to external speakers (via red/white cables) and to the TV speakers (via HDMI) I can have both sources playing the audio simultaneously and there is definite lag coming from the HDMI audio.

All digital displays made over the last few years incorporate an audio delay circuit for both digital and analog audio inputs to compensate for the time delay created by the video processing circuit. Due to the variety fo technologies still used this delay should occur at the display. Most current A/V receivers include a delay adjustment to get the that audio in sync with the video. The technical term is lip sync.

While I have not tested this... if you take the audio out of any source as analog into an A/V receiver or amp while running HDMI to your TV and use the TV speakers at the same time you may very well have a delay because the TV will delay the audio to prevent or reduce a lip sync problem with the delayed video (due to video processing). This is not recommended for a multitude of reasons and while this worked for decades with the old TV system and analog display technology you may easily run into problems with digital technology - you need to use either the TV speakers or the A/V receiver, not both. It sounds like you are using both yet...

You say this only occurs on certain channels.

It appears you do not have another HDMI source product to verify what is going on.

The only other possibility, and extremely slight, is a firmware update from LG. Sorry to tell you but you may find discussing that much less getting it from LG like pulling teeth.

My guess says it's the cable box/cable company.

Hello inaba . .

"Splurge" . . . treat yourself as an early Holiday Gift, etc., to an "inexpensive" Surround System, connecting it to that Cable Box coaxial digital out or with a Toslink optical ... turning OFF the TVs internal Audio altogether as Richard said .... and you WILL be amazed at what you have been otherwise missing !

NOT necessary to spend .. "more-than-the-HDTV" .. either!

The current offering of ONKYO HT-S5200 .. {or, even Sony's HT-SS360,as a decidedly-second choice} .. have been found to provide quite satisfactory results for an economical outlay!

No ... "complex installation" ... whatever!

everett

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[ under $500, no tax except NY + KY & free shipping]

I too have an LG 47LH-90 and I am having the same exact problem. It has been driving me nuts! I use Brighthouse cable with a HD DVR cable box. RGB (composite) has no audio lag. I have attached a smaller HDTV (does not do 1080P) but I do not get the lag. I really feel it is the LG TV causing the problems and I would like to know your model/type. I am going to contact LG tomorrow. Of note however is that it does NOT happen on all channels and I have a Blue Ray DVD that uses HDMI and no audio lag there either. It is driving me bonkers!


Thanks

CoChese

I contacted LG support and they stated they have others who have complained about "lip-sync" problems while using a cable box and HDMI. They asked me numerous questions and stated they have developed software to fix the problem. I answered their questions and I am awaiting a response to a link to allow me to upgrade the firmware in the TV to fix the lag.

I'll let ya know what they say.

CoChese

'I am awaiting a response to a link to allow me to upgrade the firmware in the TV to fix the lag."



Thats good news. I contacted them almost a month ago and didn't get much help. I guess they have since realized the problem and developed a solution. Please do let me know when you hear something back from them. Thanks!

inaba116,

It would be very helpful to the topic of this thread if you would provide the model number of your display.

Thanks

Yeah, no prob. It is a LG 42LH30.

I would be more than happy to let you know as soon as I get something. I take it you also went to their website and filed
an online complaint?? I did and left them my e-mail address. Here is part of their response;

*****We sincerely regret that you have experienced difficulties with your LG Product.
There are some of our units depending on the model that are presenting lip-sync issues when using a cable box connected by HDMI. It is not that the television has a problem; it is because some cable boxes are recycled and hardware’s are not updated.
In order to avoid customer dissatisfaction LG Electronics decided to create software that once installed on the television, it will eliminate any lip-sync issues that are present.
We will need the following information to proceed with your case:
Complete product code of the TV i.e.(47lg50-ud. ausglvm)
Name of the Cable Provider:
What is the connection when lip sync occurred? -
If with Cable box, what is the cable box model no. and brand?
How much is the lip sync? 1/2 sec? 1 secs.? Or more?
Lip sync on particular channel or all channels?
Does picture come out first then audio lag occurs?
Does customer have other unit he can compare with?
If you have other questions or concerns, please do not hesitate to contact us again either via email, or by calling our customer service division at 800-243-0000 at your convenience.***********
This was from customerservice@lge.com .
Fortunately I do have another HDTV I can use to compare. I sent a reply with the info above and you might want to copy this and send them your info...Hopefully, we'll get a fix.. I am using my component connector for now.

To whom it may concern,

I e-mailed the LG customer support person who I have been dealing with asking for a status of a link to download the firmware. I was given a runaround response and as such asked the person to get their supervisor. The supervisor responded stating there is no link to a firmware available and that a technician with a "technicians remote" will have to come to my home and install the firmware and make some changes that customers are not authorized to do using this technicians remote. The supervisor informed me that I should be contacted within 2 weeks by someone who would schedule a time to show up and do this to my 47 inch LH-90 TV.
Therefore, anyone with an LG HDTV and lip sync problems, should contact the LG customer support and advise them of the information I previously posted (TV Type, cable box type, etc) and let them know you have lip sync problems. Per the supervisor I dealt with, they contact you on a first come first serve basis.

I will continue to provide updates here.

Later

CoChese