AV Receivers

[arthurfuxake]

Right,
I had an all-in-one dvd unit which had it's own built in amp to drive the 6 speakers that came with it. The dvd unit has died, and I have replaced it with a new dvd recorder. I now have no way of connecting speakers to the dvd recorder, so am listening to the sound from the dvd through my tv speakers(sounds really crap in stereo!). I'm looking at buying an AV receiver unit(I think that is what I need). I have a dvd and a sky+ box. I've had a look at these AV receivers, and it looks like they feed the video(and sound) from my current sky+ box through the receiver(via optical and composite video) to the tv. Now, I plan on getting the sky+HD box and a new 32" HD LCD tv in the near future. My question is, will these AV receivers feed the HD LCD tv with the HD signal, or will I have to feed the video from the sky+HD box directly to the TV, and thus bypass the AV receiver? i.e. will the AV receiver pass the hd signal from the sky box through to the tv, or do i need to get a HD compatible AV receiver?

 

[AndyMac]

The fact the video signal is HD is irrelevant as the amp is only looping it, not processing it in anyway. It's more of a case that the LCD/Sky+/DVD recorder have optical in/output compatible with the amp. I wouldn't loop it through the amp anyway as this is just adding circuitry to the HD signal and is just unnecessary.

 

[arthurfuxake]

Thanks Andy, I'll bypass the AV receiver for the video signal then.

My thoughts now are:
If the audio feed from the dvd/sky+ goes through the AV receiver, and the video feed is direct to the tv, will there be any lip-sync issues. The video feed goes through less circuitry, and hence arrives at destination quicker than the audio signal that has to go through the AV receiver circuitry? Will the delay be noticeable?

 

[AndyMac]

Not unless your AV receiver is situated in another country!
That's a bit like asking if they'll be lip synch issues if you sit further away from your telly, as light travels faster than sound. Sorry couldn't resist!

 

[madvw]

You'll probably (almost definitely) get lip sync issues when using a separate AV receiver with a HD display. This is because of the processing lag of the display.

Your best way to be prepared is to buy a receiver that has additional lip-sync controls so that you can tune it for yout HD display - Most have a 200 ms delay for HD, or some are tunable in 20ms steps.

However, you could risk it with a cheaper model, and try and accomplish the same by playing with the speaker distance configuration on the receiver (but obviously keep the speakers in the same places).

 

[AndyMac]

But that's a problem regardless of whether you run the picture through the AV unit or not

 

[god_thats_quick]

I doubt the lip sync will actually be a real problem to be honest, although I haven't played with HD stuff much, but a digital signal would be the same as the DVI feed from my computer to my projector and the sound and video output from the DVD player / Sky should be in sync leaving the box so I reckon you'll be fine!

The benefit of routing video through the AV Amp is the ability to switch between video sources, however very few have switching abilities for DVI or HDMI as required for a real HD signal so I wouldn't worry about that.

 

[madvw]

Yup, you'll get these issues putting video straight to diaplay or through AV receiver.

The problem is when using non-native sources to whatever spec your display is - i.e any non HD source such as DVD.

The scalers currently in most displays are not fast enough to do it instantly - so you will get noticable lip sync issues, although as new units come out with faster processors it should get less noticable.

You really can't compare DVI or DVD to a projector to a HD display.

 

[god_thats_quick]

[ QUOTE ]
You really can't compare DVI or DVD to a projector to a HD display.

[/ QUOTE ]

Why not? my DLP projector is probably higher resolution that quite a few "HD" displays and unless it's being fed a DVI (Digital) feed from the computer at the native resolution for the projector it also has to scale images to fit the screen correctly. However I can see that this would be very display dependant but as my projector is now 3-4 years old in design I'm surprised that processing is so bad on modern HD displays from what you say!