• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

Lip sync issues Yamaha DSP A1000

Ping Man

Standard Member
Hi,

So after 18 years my Sony CRT died and I've now got a Panasonic 47ET5 to replace it. Have now hooked up my rather ancient Yamaha DSPA1000 with two Monitor Audio main speakers either side, Kenwood CS-6 centre speaker and 2 Yamaha NS-E80 rear speakers. I've had to fit a CYP AU-D3 DAC to get audio from the TV to the DSPA1000.

With the DSPA1000 the centre mode can be set to normal, wide or phantom. With the normal or wide setting used the centre speaker is a fraction behind the TV with the volume up on the TV. However when set to phantom, the centre speaker is I assume ignored and when both volumes are both turned up, lip sync is perfect with vocals going through the two main speakers.

Same issues when running sound from the blu-ray player, the sound is slightly out when the DSPA1000 is set to normal or wide (not that I have the TV and DSPA1000 turned up at the same time normally, I was just using it as a reference).

Never had any lip sync issues with the old CRT set up. Could it be that the new flatscreen is nearer the wall and that the centre speaker is effectively 12 inches in front of the screen that could be causing the issue?

Any suggestions or solutions welcomed, thanks for taking the time to read the post.:)
 

Mark.Yudkin

Distinguished Member
With the normal or wide setting used the centre speaker is a fraction behind the TV with the volume up on the TV.
...
Never had any lip sync issues with the old CRT set up. Could it be that the new flatscreen is nearer the wall and that the centre speaker is effectively 12 inches in front of the screen that could be causing the issue?
Having the speakers in front of the screen would make the sound arrive just under 1ms earlier, not later, and provided you didn't have the TV's sound on, that isn't enough to be noticable (a TV frame lasts 40ms). My guess is that the delay is caused by the time taken by your Yamaha DSP A1000 to create the simulated centre mode form the CYPs stereo output.

For the bluray player, are you using a direct connection from the player to the amp, or are your routing the audio through the TV?
 

Ping Man

Standard Member
Hi Mark,

Thanks for the reply.

I'll have another listen and post back to see if I can be sure if the sound from the centre is slightly earlier or later.

If the delay was caused by the CYP output, then when I set the DSP A1000 to phantom mode (so the signal doesn't go to the centre speaker), I would notice a delay between the TV sound and surround sound but this is the only time there is no noticeable delay. So from that point of view I had ruled out the CYP.

The bluray has a direct connection to the DSPA1000 and as that uses phono plugs to connect to it and gives me the same lip sync issue. So as I was going through direct and not using the CYP to put sound in, again I had ruled out the CYP.
 

Mark.Yudkin

Distinguished Member
The amount of delay introduced by the audio conversion (the CYP) is minute compared to the delay caused by video processing, with the result that you should not be experiencing any synchronization issues between lip movements and seeing the picture, other than those in the source material itself.

The DSPA1000 might take a few ms to simulate the centre, which would be enough to effect a noticable difference between the TV's and the amp's speakers, but ought notto be enough enough to effect a noticable difference between what you see and what you hear - which is what is crucial.

Some TV's handle the discrepancy between audio and video processing delays by delaying the audio to match the video processing time, others don't, assuming you'll have a device further down the line to make the adjustment. Many lipsync issues are in fact down to source issues (e.g. SKY's randomly varying differences).

If you just watch TV (rather than trying to determine lipsync issues) does a discrepancy in lip movement and the sound you hear bother you, and if so, does it go away when you switch to the TV's sound (we need to rule out source issues)?
 

Ping Man

Standard Member
Thanks again for the reply Mark.

I've had another listen again last night, trying to determine if the sound is ahead or behind.

I think the issue may be the TV speakers. Being a nice thin flatscreen TV the speakers are behind the TV so I'm wondering if the difference in sound timing when the TV sound and the DSPA1000 sound are up at the same time is due to the TV being near the wall and sound bouncing off of it. The is a setting in the Panasonic menu saying distance to wall and you can have up to 30cm or over 30cm. Switching the settings around doesn't seem to make a jot of difference though! Perhaps this is why there is a difference compared to the old set up with the CRT. I'll try and ignore any slight lip syncs issues during the next few weeks and take it from there. If I'm still struggling with it I'll post back.

Thanks for the suggestions.



ATB
 

Mark.Yudkin

Distinguished Member
A 30cm difference works out to less than 1ms. With TV frames lasting 40ms, you aren't going to see any lipsync issues arising from that 30cm difference. Whatever the issue is, it isn't the 30cm distance difference.

It also isn't likely to be the TV's speakers - most TVs correctly delay the audio output to the TV's speakers so as to compensate for the delay caused by the video processing. However, in the event that your TV did not do this correctly, you would clearly observe a difference between what you hear and what you see as the actors move their lips when watching TV. Since you were using the TV as a reference, I assumed that you did not have basic problems with the TV's audio - video synchronization.

Sound bouncing off leads to boominess, but cannot not cause lipsync issues. The switch essentially reduces the bass to compensate for the boundary gain (more here).
 

Ping Man

Standard Member
Since you were using the TV as a reference, I assumed that you did not have basic problems with the TV's audio - video synchronization.

This is correct, there is no issue with the TV audio video sync.

Over the weekend I'll try and record what I'm getting and will post a link. ATB.
 

Ping Man

Standard Member
Finally got around to recording a video to explain issue. Youtube link is here.

Although I think its a lip sync issue, ignore the lip sync in the video, I'm sure there's another delay in recording onto the ipod LOL.

The sound starts off as surround only, you'll hear it change when you see the volume unmuted at the bottom of the screen. It gets muted again after a few seconds, then unmuted again at the end.

Hope this makes earlier posts more understandable.
 

Mark.Yudkin

Distinguished Member
Finally got around to recording a video to explain issue. Youtube link is here....
I'm sorry, but I'm unable to see / hear the problem from your YouTube news post.
 

The latest video from AVForums

Is 8K TV dead? Philips OLED+907, Pioneer LX505 AVR plus B&W 700 S3 Reviews & Visit + AV/HiFi News
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom