Originally Posted by b curry
Audio sync or lip-sync was added to the HDMI spec starting with version 1.3 forward.
From HDMI ORG:
"The HDMI 1.3 specification more than doubles HDMI’s bandwidth and adds support for Deep Color™ technology, a broader color space, new digital audio formats, automatic audio/video synching capability (“lip sync”), and an optional smaller connector for use with personal photo and video devices. The update reflects the determination of the HDMI founders to ensure HDMI continues evolving ahead of future consumer demands."
For this to work, all devices must be HDMI v1.3-1.3a or better. Unfortunately, it's not perfect and timing errors can sill exist. This can be or usually can be corrected via the AVR. I've yet to see an AVR that supports HDMI v1.3 that does not have audio delay settings capability.
Your Denon AVR-S510BT also has this feature. You are able to set audio delay or audio sync (lip-sync) from 0ms – 200ms for each source input as well as store the setting for each source input. It's on page 72 of the AVR-S510BT manual.
Starting with HDMI 2.0, dynamic synchronization of video and audio streams has been added. HDMI ORG is calling it dynamic auto lip-sync or DALS.
DALS is a dynamic system where receiving devices, the SINK, transmit latency information for audio and video to the EDID ﬁeld. Transmitting devices, the SOURCE, will synchronize based on the EDID latency ﬁeld information. The HDMI 2.0 DALS feature allows SINK devices to announce their latency information at any point in transmission, continuous updates, so that the SOURCE devices are aware of the correct latency.
I was aware of how to set the audio delay, but was having trouble getting satisfactory results. It turns out that my WOW calibration disc has a setting for adjusting the AV sync. When I used that, I had to set the audio delay for 150 ms. I then discovered the same AV sync pattern on Youtube just by searching for "av sync". It also turns out that I can access Youtube from both my Tivo and Amazon Fire TV... So I tested these devices with the same av sync pattern.
My Tivo needed the same delay of 150 ms. However, the amazon fire TV was perfectly synced... Hmm. It also wouldn't let me change the audio delay on the Fire TV.
After some experimentation, it turns out that if I change the AVR's Sound Mode to "Direct," then the sync seems to be spot-on regardless of which device I am using (and the AVR won't let me adjust it). If I set the Sound Mode to something else, say "DTS Surround", then I have to dial in a 150 ms delay.
I have no idea why this is. I am using frame interpolation on my projector which should
be introducing about a ~100-150 ms delay that I should
need to compensate for. The only thing I can think of is that the AVR is doing this automatically when the Sound Mode is set to "Direct".
Anyway, I'm going to leave it set to "Direct" and see how it goes.
Thanks to everyone who replied!