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sound lag on Panasonic Home Theatre toslink input/ouput?
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Amanda Riphnykhazova
Sep 7, 2012, 5:57:54 PM9/7/12
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Hoping this is a sci.electronics.repair problem: This concerns a Panasonic SAPT760 home theatre system which has been repaired once under warranty and suddenly new problems have appeared. (most of which I can live with but I was wondering if anyone here recognised the symptoms).
There is an annoying half-second lag on sound output when played through the SAPT-760. Panasonic HT tech support said it is caused by the (Panasonic) Plasma TV. TV Tech support at first agreed and sent me a BIOS upgrade. The lag reduced to about a tenth of a second or less (this was almost definitely a coincidence) and has since increased back to about a half second again. If I play the TV sound at the same time as the digital HT, sound, you can hear the marked lag, with the TV sound being, of course lag-less.
Other problems with the HT setup which may or may not be relevant are that when I first got it, my Nano played and charged through the built in dock. Now it shows incompatibility which Panasonic confirms! But I am wondering how it played and charged formerly??
More importantly perhaps, on initial turn-on, when switching to the Toslink input, I initially get no sound whatsoever. Leaving it on digital input, after a few minutes, I start to hear a low frequency (3-4 hertz?) popping which slowly increases to about 10-15 Hz before the unit starts to recognise the popping as the light based sound it is supposed to be decoding and then the sound quality is generally OK with no popping. But with that annoying lag. All other inputs (including the DVD) are OK, which told Panasonic Tech support that the unit is performing properly and that the problem must be with the signal coming out of the TV.
On one call, the TV people said they found some reference to an adjustable lag on the HT system but the HT people deny that any adjustment on this (or resetting to defaults) exists. There IS a time delay adjustment on the DVD side but it is set to zero.
Yes I DO know that there is some millisecond adjustment on individual speakers but this problem concerns a general half second lag on all speakers and all speakers seem to be set up OK on the in-built DVD system.
One last thing: The lag isn't always there: Sometimes the toslink sound (i.e. the sound from the tv into the HT) dissolves into a generalised crackling.
There is an annoying half-second lag on sound output when played through the SAPT-760. Panasonic HT tech support said it is caused by the (Panasonic) Plasma TV. TV Tech support at first agreed and sent me a BIOS upgrade. The lag reduced to about a tenth of a second or less (this was almost definitely a coincidence) and has since increased back to about a half second again. If I play the TV sound at the same time as the digital HT, sound, you can hear the marked lag, with the TV sound being, of course lag-less.
Other problems with the HT setup which may or may not be relevant are that when I first got it, my Nano played and charged through the built in dock. Now it shows incompatibility which Panasonic confirms! But I am wondering how it played and charged formerly??
More importantly perhaps, on initial turn-on, when switching to the Toslink input, I initially get no sound whatsoever. Leaving it on digital input, after a few minutes, I start to hear a low frequency (3-4 hertz?) popping which slowly increases to about 10-15 Hz before the unit starts to recognise the popping as the light based sound it is supposed to be decoding and then the sound quality is generally OK with no popping. But with that annoying lag. All other inputs (including the DVD) are OK, which told Panasonic Tech support that the unit is performing properly and that the problem must be with the signal coming out of the TV.
On one call, the TV people said they found some reference to an adjustable lag on the HT system but the HT people deny that any adjustment on this (or resetting to defaults) exists. There IS a time delay adjustment on the DVD side but it is set to zero.
Yes I DO know that there is some millisecond adjustment on individual speakers but this problem concerns a general half second lag on all speakers and all speakers seem to be set up OK on the in-built DVD system.
One last thing: The lag isn't always there: Sometimes the toslink sound (i.e. the sound from the tv into the HT) dissolves into a generalised crackling.
Jeff Liebermann
Sep 7, 2012, 11:05:56 PM9/7/12
to
On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
<license...@gmail.com> wrote:
(... too lazy to word wrap...)
Try turning off the Dolby digital audio when using the Toslink. Dolby
can add about 0.5 seconds delay. DTS audio might have less of a delay
and is worth trying. Toslink does NOT have a lip sync specification
because there is no associated video channel. That might explain why
Panasonic isn't very responsive to the problem. If you want tolerable
(not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
a functional spec.
The strange noises are definitely not normal and should be
investigated. However, I have no clue from where they originate.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
<license...@gmail.com> wrote:
(... too lazy to word wrap...)
Try turning off the Dolby digital audio when using the Toslink. Dolby
can add about 0.5 seconds delay. DTS audio might have less of a delay
and is worth trying. Toslink does NOT have a lip sync specification
because there is no associated video channel. That might explain why
Panasonic isn't very responsive to the problem. If you want tolerable
(not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
a functional spec.
The strange noises are definitely not normal and should be
investigated. However, I have no clue from where they originate.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Amanda Riphnykhazova
Sep 10, 2012, 9:54:11 AM9/10/12
to
On Friday, September 7, 2012 11:05:53 PM UTC-4, Jeff Liebermann wrote:
> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>
> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>
> <license> wrote:
>
> (... too lazy to word wrap...)
>
>
>
> Try turning off the Dolby digital audio when using the Toslink. Dolby
>
> can add about 0.5 seconds delay. DTS audio might have less of a delay
>
> and is worth trying. Toslink does NOT have a lip sync specification
>
> because there is no associated video channel. That might explain why
>
> Panasonic isn't very responsive to the problem. If you want tolerable
>
> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>
> a functional spec.
>
>
>
> The strange noises are definitely not normal and should be
>
> investigated. However, I have no clue from where they originate.
>
: JeffLiebermann
>
> (... too lazy to word wrap...)
>
>
>
> Try turning off the Dolby digital audio when using the Toslink. Dolby
>
> can add about 0.5 seconds delay. DTS audio might have less of a delay
>
> and is worth trying. Toslink does NOT have a lip sync specification
>
> because there is no associated video channel. That might explain why
>
> Panasonic isn't very responsive to the problem. If you want tolerable
>
> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>
> a functional spec.
>
>
>
> The strange noises are definitely not normal and should be
>
> investigated. However, I have no clue from where they originate.
>
This problem has persisted now for 6-8 months with differing degrees of intensity but since I posted, the digital sound first disappeared completely, then the next day came back when I turned off the Dolby (and without any real noticeable lag) and then today the lag came back with such a vengeance that I thought that the HT unit had defaulted back to Dolby (no, it hadn't).
Cydrome Leader
Sep 23, 2012, 12:10:47 AM9/23/12
to
Jeff Liebermann <je...@cruzio.com> wrote:
> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
> <license...@gmail.com> wrote:
> (... too lazy to word wrap...)
>
> Try turning off the Dolby digital audio when using the Toslink. Dolby
> can add about 0.5 seconds delay. DTS audio might have less of a delay
> and is worth trying. Toslink does NOT have a lip sync specification
> because there is no associated video channel. That might explain why
> Panasonic isn't very responsive to the problem. If you want tolerable
> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
> a functional spec.
I never thought about this before.
> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
> <license...@gmail.com> wrote:
> (... too lazy to word wrap...)
>
> Try turning off the Dolby digital audio when using the Toslink. Dolby
> can add about 0.5 seconds delay. DTS audio might have less of a delay
> and is worth trying. Toslink does NOT have a lip sync specification
> because there is no associated video channel. That might explain why
> Panasonic isn't very responsive to the problem. If you want tolerable
> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
> a functional spec.
Does that mean that any old surround sound-ish system could in theory have
audio horribly lagged and off from the video from the source such a DVD?
I've noticed there are delay settings on most audio decodes but, I've not
noticed or though about there being sync issues with the audio as a whole.
MiniDV was another story, and a complete waste of my time when I used it.
Jeff Liebermann
Sep 23, 2012, 9:37:20 PM9/23/12
to
On Sun, 23 Sep 2012 04:10:47 +0000 (UTC), Cydrome Leader
<pres...@MUNGEpanix.com> wrote:
>Jeff Liebermann <je...@cruzio.com> wrote:
>> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>> <license...@gmail.com> wrote:
>> (... too lazy to word wrap...)
>>
>> Try turning off the Dolby digital audio when using the Toslink. Dolby
>> can add about 0.5 seconds delay. DTS audio might have less of a delay
>> and is worth trying. Toslink does NOT have a lip sync specification
>> because there is no associated video channel. That might explain why
>> Panasonic isn't very responsive to the problem. If you want tolerable
>> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>> a functional spec.
>
>I never thought about this before.
>
>Does that mean that any old surround sound-ish system could in theory have
>audio horribly lagged and off from the video from the source such a DVD?
I don't know. I've never tried surround sound on a DVD video
<pres...@MUNGEpanix.com> wrote:
>Jeff Liebermann <je...@cruzio.com> wrote:
>> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>> <license...@gmail.com> wrote:
>> (... too lazy to word wrap...)
>>
>> Try turning off the Dolby digital audio when using the Toslink. Dolby
>> can add about 0.5 seconds delay. DTS audio might have less of a delay
>> and is worth trying. Toslink does NOT have a lip sync specification
>> because there is no associated video channel. That might explain why
>> Panasonic isn't very responsive to the problem. If you want tolerable
>> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>> a functional spec.
>
>I never thought about this before.
>
>Does that mean that any old surround sound-ish system could in theory have
>audio horribly lagged and off from the video from the source such a DVD?
playback, mostly because all my boxes are ordinary stereo. No 5.1
anywhere. Theoretically, the lip sync could be a problem because
there are no specs. The bulk of the delay is not in the audio system.
It's in the video processing. Some detail:
<http://www.avsforum.com/t/875004/does-hdmi-1-3-fix-lip-sync-issues>
Incidentally, my DirecTV R16/300 composite video is noticeably out of
sync with the audio. However, the component video output is fairly
close. My guess(tm) is that DTV optimized it for component video
assuming that nobody will be using composite video. The R16/300
doesn't have HDMI.
>I've noticed there are delay settings on most audio decodes but, I've not
>noticed or though about there being sync issues with the audio as a whole.
>MiniDV was another story, and a complete waste of my time when I used it.
Cydrome Leader
Sep 26, 2012, 2:22:37 AM9/26/12
to
Jeff Liebermann <je...@cruzio.com> wrote:
> On Sun, 23 Sep 2012 04:10:47 +0000 (UTC), Cydrome Leader
> <pres...@MUNGEpanix.com> wrote:
>
>>Jeff Liebermann <je...@cruzio.com> wrote:
>>> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>>> <license...@gmail.com> wrote:
>>> (... too lazy to word wrap...)
>>>
>>> Try turning off the Dolby digital audio when using the Toslink. Dolby
>>> can add about 0.5 seconds delay. DTS audio might have less of a delay
>>> and is worth trying. Toslink does NOT have a lip sync specification
>>> because there is no associated video channel. That might explain why
>>> Panasonic isn't very responsive to the problem. If you want tolerable
>>> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>>> a functional spec.
>>
>>I never thought about this before.
>>
>>Does that mean that any old surround sound-ish system could in theory have
>>audio horribly lagged and off from the video from the source such a DVD?
>
> I don't know. I've never tried surround sound on a DVD video
> playback, mostly because all my boxes are ordinary stereo. No 5.1
> anywhere. Theoretically, the lip sync could be a problem because
> there are no specs. The bulk of the delay is not in the audio system.
> It's in the video processing. Some detail:
> <http://www.avsforum.com/t/875004/does-hdmi-1-3-fix-lip-sync-issues>
I'm still living in the past with a 1998 sony DVP S500D DVD player and
> On Sun, 23 Sep 2012 04:10:47 +0000 (UTC), Cydrome Leader
> <pres...@MUNGEpanix.com> wrote:
>
>>Jeff Liebermann <je...@cruzio.com> wrote:
>>> On Fri, 7 Sep 2012 14:57:54 -0700 (PDT), Amanda Riphnykhazova
>>> <license...@gmail.com> wrote:
>>> (... too lazy to word wrap...)
>>>
>>> Try turning off the Dolby digital audio when using the Toslink. Dolby
>>> can add about 0.5 seconds delay. DTS audio might have less of a delay
>>> and is worth trying. Toslink does NOT have a lip sync specification
>>> because there is no associated video channel. That might explain why
>>> Panasonic isn't very responsive to the problem. If you want tolerable
>>> (not perfect) lip sync, HDMI 1.3 and 1.4 are the only interfaces with
>>> a functional spec.
>>
>>I never thought about this before.
>>
>>Does that mean that any old surround sound-ish system could in theory have
>>audio horribly lagged and off from the video from the source such a DVD?
>
> I don't know. I've never tried surround sound on a DVD video
> playback, mostly because all my boxes are ordinary stereo. No 5.1
> anywhere. Theoretically, the lip sync could be a problem because
> there are no specs. The bulk of the delay is not in the audio system.
> It's in the video processing. Some detail:
> <http://www.avsforum.com/t/875004/does-hdmi-1-3-fix-lip-sync-issues>
some sort of equally old Technics sourround sound decoder. They connect
with some sort of toslink-ish fiber optic cable, and pretty much work with
anything but the movie Hellraiser 2.
I just added WD Live media player box to the museum of 1990s home thatre
and it mostly works with the same surround sound decoder, but will freeze
things up requiring a reboot from time to time. I've not noticed audio
sync problems, and I watch video over component video or svideo with the
DVD player and HDMI to a projector with the WD live box. I've never used
audio over HDMI, and have no idea where you'd even intercept the audio
signals and listen to them in the first place.
> Incidentally, my DirecTV R16/300 composite video is noticeably out of
> sync with the audio. However, the component video output is fairly
> close. My guess(tm) is that DTV optimized it for component video
> assuming that nobody will be using composite video. The R16/300
> doesn't have HDMI.
>
>>I've noticed there are delay settings on most audio decodes but, I've not
>>noticed or though about there being sync issues with the audio as a whole.
>
> The only ones that I've seen that are close use HDMI 1.3.
>
>>MiniDV was another story, and a complete waste of my time when I used it.
>
> I missed that one.
tape. Audio could and would drift from the video if you played the tapes
back on a computer, but from the analog ports on a player, they were
always OK.
I'm still trying to figure out how that was even possible, but it was, and
the non-consumer DV tape formats never had that problem as they had some
sort of time sync info between the streams.
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