Televisions - sound/picture mis-match

[woodyray]

Hi, I hope that someone can help with the following.

We have a kitchen diner with an archway to the main living room. We have an HD Ready Toshiba TV in the diner, and until recently, a Sony HD Ready TV in the living room.

The sounds/pictures have always matched on BBC1 & BBC2, not London ITV (but did so if one was on channel 3, the other on 808), and not Channel 4 & 5.

We just replaced the Sony with a larger Full HD Samsung in the living room.

The problem is that there is now a mismatch between the TVs on ALL stations - with some stations the sound/picture is a fraction of time earlier on one TV than the other, with other stations they are reversed. This give a horrible echo effect when both are on together.

We are on an aerial going into a booster, which then feeds into a digital recorder. This feeds into a splitter, which supplies both TVs via co-axial cables. The digital recorder also feeds direct to the living room TV via HDMI (but it makes no difference to the problem if this is disconnected).

I would appreciate advice as to whether there is any way to overcome this problem.
Ray

 

[Diyisfun]

I think its the electronics for the full HD. I have the same problem.
When we have both TV's on I go to non HD on the full HD TV, ie channel 1 not 101.

 

[woodyray]

Unfortunately it's the same when the new TV is on HD or non-HD stations. Thanks anyway.

 

[OwainDIYer]

Because of the processing involved internally, even if you bypass the TVs' digital inputs and feed them all analogue from the same external set-top box you may not hav exact synchronisation between multiple TVs.

If you replace all the TVs with completely analogue CRTs you are much more likely to get synchrnosied audio and video between sets.

 

[Lucid]

OwainDIYer is on the right lines here. There's a lot of processing going on inside the average flatscreen TV, so even if you make sure both TVs are on the same channel to avoid the broadcast sync difference between SD and HD then you still have what each TV is doing to both picture and sound in order to display it. I'll give you a practical example. There's a lot of people who play console games. One big problem for first person action games is the delay between what the console is sending out and what is being seen on screen. This is referred to as Lag. In essence there's enough of a delay that when you see the enemy on screen in CoD they've had anything up to a quarter second advantage and shot your character first. Serious gamers spend a lot of time looking for reviews on TVs that measure Lag. There's also a mode on some TVs to bypass all the "picture enhancing" settings and feed the signal in with minimal delay. You'll find this referred to as variously as Game Mode or PC Mode.

Lag increases in proportion to how many of the enhancement features are used. The worst offender is Dynamic picture mode. If your TV is 100/120 Hz then that will improve the picture but increase the Lag too. If there are additional settings for frame recreation or frame smoothing then again the Lag will get larger. Sharpness, Dynamic Contrast, Colour Enhancer, etc etc.... anything where the TV has to hold and analyse the picture to apply some kind of fix will make Lag worse.

 

[woodyray]

Thanks for your very interesting replies. Assuming that it is due to the internal electronics, I guess I will be very unlikely to be able to solve the problem. Even I replace the older TV to end up with two of the same make, I assume that it wouldn't guarantee they would be in synch. and would be an expensive experiment.

Interestingly, last night we found that one TV was showing ITV Anglia news, the new one showing London ITV news.
It is possible that the TVs are picking up from different transmitters?. Why I ask is because our TV aerial is pointing south-west (?Crystal Palace). However, there is another transmitter due North of us. Our aerial is the horizontal type, and I've been told that these can pick up signals coming from behind as well as from the front.
If the is the case, could this also be part of the problem? Or is this still due to the different electronics within the sets?
Many thanks.

 

[Lucid]

You can resolve the problem of picking up the wrong transmitter by doing a manual scan. It might help if you do a "First time installation" but with the aerial disconnected to wipe the TV memory.

 

[OwainDIYer]

Interestingly, last night we found that one TV was showing ITV Anglia news, the new one showing London ITV news.
... Or is this still due to the different electronics within the sets?
Many thanks.

Different sets have different sensitivities, one may be ignoring a weak signal while the other might latch onto it. Also check you rlocation / posycode settinsg in the sets and they might think you live somewhere you don't.