...and it's not just a Sky problem–I've pointed this out before, but you may notice differences from channel to channel, program to program, all from the same provider (e.g., Comcast in the States), exclusive of cable/satellite box hardware-induced delays.

The issue is largely a newer manifestation of the old AV chestnut of audio / video synchronization. Content providers use different systems, and there's no way (period) to insure that the signals will EVER be synchronized without a major re-think about digital media encoding in general, sorry.

At least with a DVD player, you have one source with a known RANGE of delays (depending on decoding format) between the video and audio streams.

Maybe the issue here is one of the degree of the delay.

As I say I've not been able to reproduce this via other DSP/digital combinations nor, trawling various BB's, have I found others who could. If however there is an intrisic delay in some digital broadcasts then that delay must be of the order of a few milliseconds and not noticable to most people.

I see a delay of 250ms - a quarter of a second - noticable to anyone who can see. Read this paragraph aloud and figure out how many words per second you speak. Now think about delaying the sound by 250ms.

How do I know it's 250ms? Call me a saddo but in trying to figure out a way to quantify it early on I thought of Countdown on Ch 4. The clock music lasts 30 seconds and has near enough 60 beats, i.e 500ms. When I listened with both the n-vi and my TV's speakers I got double the number of beats evenly spaced, i.e. 250ms.

Now this is such a gross error that I cannot believe no-one using Sky has pointed this out if this is their fault. This is why I believe it is a time delay introduced in digital optical input the n-vi. This is what I thought Naim had acknowledged and were addressing.

Duncan

John

Re: cancelling your order ...

You may think that, I couldn't possibly comment.

Duncan

Lip-sync on SKY.

I’ve Sky and I find lip sync problems sometimes, it is down to my Panasonic SKY box, not my Naim kit. To fix it I re-boot the skybox, then it’s ok for a few months.

Also; if you are using SKY into an n-Vi you have to ensure the sample rate is correct. SKY transmits at 48kHz and should send that info in the SPDIF data. On some models they do not! The n-Vi then assumes it is 44.1kHz and the audio will sound out of sync, slow and glitches! If it sounds ok it is not that, but if it is this is how you change it. Select your SKY input, Press and hold ‘angle’ on the n-Vi remote, a service menu will appear, select PCM Freq, change the relevant input from AUTO to 48kHz.

If it is none of the above, do this test.
Connect both the analogue and digital outputs from your skybox to the n-Vi.
Switch between the two on the n-Vi. If the delay on the analogue and digital signals is the same, i.e. the analogue has the same problem we know conclusively that it is exclusively the skybox at fault, as the analogue signal will travel roughly at the sound of light! If the lip-sync is worse on digital it needs more investigation.

But remember if the audio is delayed from the skybox, no audio decoder can fix that!

there is a very slight lyp-sync issue with telewest which is acceptable to me, its if the n-vi makes it worse which bothers me ? i dont know if there is a delay with sky in general terms compared with analogue or even freeview receivers, there has always been a delay with telewest compared to the other two,sometimes as much as 2 seconds behind the portable analogue tv

110dB,

Thanks for your reply.

Do you see lip sync delays approaching 250ms with your Sky? I've just deep re-booted (power cable out) the Sky box (Pace Sky+). The problem is still there.

I checked the Angle menu. I can see a "Status" submenu with "PCM - A0/1/2/34" numbers and a few others. In the "Settings" submenu there is nothing that looks like a PCM frequency. Are you coming from an AV2 POV? Not sure I need this as apart from the delay the sounds is fine.

Unfortunately you can't plug Sky into the n-vi on its analogue inputs as there are no A to D converters on those inputs (unlike the AV2). I.e. you cannot apply DSP modes to n-vi's analogue inputs. Hence why I am keen to resolve this issue on the digital optical input - it is my only option, and the only option for anyone with an external TV box who wants to DSP the output via an n-vi.

As an aside, I just switched to an analogue input (A1, my LP12) to confirm there is no DSP on it. When I switched back to D1 (Sky+) there was no sound. Needed a back panel reboot. I have to do this three or four times a night. You may see where my frustrations are coming from …

Duncan

John,

Synching audio and video has been a problem with the media for a very long time, be it broadcast media or AV media (DVD/VHS). Most decent surround processors have a lip-synch feature to help the problem exhibited by the original medium i.e. a (typically digital) broadcast or a DVD. This is not a fault of an n-Vi or, indeed, your AVR3805 which also has a lip-sync feature! It's only very basic processors that do not have a feature of this sort, which is a bad thing. Incidentally, the n-Vi is one of the few that can handle really gross errors of 250ms.

I think the waiting has really got to you John.

I have this very morning passed a digital (optical and co-axial) and analogue signal from a DVD5 to an n-vi (analogue1, digital1 and 2).

with a film playing from the DVD5 (both 5.1 and 2.0) through a sim2 projector and the sound going via the n-vi digital/analogue inputs, there is NO delay.

I have also run the 2.0 signal as PLII, neo6 etc....still NO delay.

This message has been edited. Last edited by: Adam Meredith,

The change of sample rate (available from service menu) is only available on 75 or later PIC code.

AV@Naim

Thanks for that. That seems to be a conclusive test although it would be neat if you could try with Sky comparing A1 and D1 from the same Sky box.

I've spent a while on the phone to Sky this morning who are certain that this level of delay is not a problem with their service. I've also just plugged the analogue from Sky into A1 and there are no delays on that (but no DSP either!).

So this leaves me a couple of choices:

1) Wait for my new n-vi to arrive and hope that the issue disappears. The fact that my "first gen" n-vi is a sick puppy in many ways may be clouding the issue.

2) If it persists with the new box in place, maybe look to change my Sky+ to a newer box. Mine is at least three years old. "First gen" again. A friends Sky+, a bit newer, has no such problem with it's dig opt output.

Duncan

duncan,

On the n-Vi:-

Can you tell me what values are opposite A0, A1, A2, A3, A4 with your sky box attached and running as normal via n-Vi.

AV@Naim

The numbers are:

A0 000
A1 100
A2 000
A3 002
A4 000

Duncan

Duncan,

To set the PCM freq:
Press and hold angle.The service menu will appear
Select PCM FREQ - it is on the 3rd line down.
Then select D1 (optical)
Then select 48kHz.

PS my sky box would be more than 1/4 second!
Its been ok for a few months now.

What s/ware are you running?
I've got V163 and V75 - working fine for me!
(press and hold PROG to find your version.

As I said, he wont be able to do this on pre 75 firmware

Problems with lypsync

I have had the same problem as the post above but have noticed on Sky+, that when watching a pre-recoded program there are no problems with lyp-sync, I assume that is because the data is coming from the hard drive and not from a satellite.

I'll try the set-up as suggested 110db!