EDID (Changing Priority Audio Processing Mode) 55UB9500
SUBJECT: AC3 and PCM Audio issues:
1ST AUDIO ISSUE: LIP SYNC
On a Digital Channel there are three primary audio streams LG TVs can process. One is PCM (Stereo), another is
AC3 (Dolby®). And the other is DTS® (Digital Theater System). AC3 and DTS is where the problem with Lip Sync resides.
From the Factory, EDID Software tells the processor to Ignore AC3 and DTS and only process PCM (If all streams are
present). The Lip Sync adjustment only affects AC3 or DTS audio, (Digital Audio).
If the Channel being received is only providing PCM, then the TV has no choice but to process PCM audio.
The Lip Sync adjustment does not affect PCM audio.
The Servicer/Customer has no way of telling what type of Audio stream is being processed on any channel without having
additional test equipment or by having a high end audio processor.
If the Lip Sync adjustment just happens to be on a channel with AC3 or a DVD with DTS audio and there is a lip sync audio
issues andanadjustmentismadeviatheIn menutheTVis “Fixed” thatdelayparameter and an adjustment is made via the In-Start menu, the TV is Fixed into that delay parameter.
If the customer moves or changes providers for their TV source, now the TV is incorrectly adjusted and will now require
another service call to fix the Lip Sync issue again. The customer must be made aware of this fact.
The Channel can have a lip sync issue only on one channel or at a specific program on a specific channel.
So Instead of adjusting the Lip j g Sync through the In-Start menu, the customer should adjust Lip Sync issues using the pyg , j p y g
Customer’s Settings Menu. “Sound” “AV Sync Adj” Turn “AV Sync Adj” to “ON”.
Then the Customer can select if they need to adjust the “Audio Delay” or “Bypass”. Audio can be adjusted for -5 (Audio
leads video) to +20 (Video leads Audio).
2ND AUDIO ISSUE: OPTICAL AUDIO OUTPUT
O DiitlChlthtditLGTV O iPCM(St)dththiAC3(Dlb On a Digital Channel there are two audio streams LG TVs can ®) process. One is PCM (Stereo) and the other is AC3 (Dolby).
AC3 (Digital) is the only stream which can carry Surround Sound information.
