Latency With Home Theater Pass-Through Use Resulting in Audio Sync Issues
Does anyone know the latency caused by the C658 when using it as a pass-through from an AVR/Pre-Pro?
Asked another way, has anyone using the C658 as a pass-through from their AVR/Pre-Pro noticed audio sync issues and if so, how did you resolve the issue? Have you played videogames with this setup?
There are a number of issues raised by this question. The answers may render the question without consequence in the context of watching video. However, the answer as to C658 latency will likely be relevant to those who use their system to videogame.
I am considering the C658 to use as a streamer/preamp connected to my amp, as well as passing through my AVR/Pre-Pro for when I want to watch movies/TV. I am also now considering the MiniDSP SHD which has similar functions to the C658 (DIRAC streamer/preamp w/pass-through functionality). It has been stated that the MiniDSP SHD has a 25ms latency regardless of whether Dirac Live is engaged or not when using it as a pass-through. SOURCE
. Such latency could be bothersome - both for dialogue (lip sync - particularly for non-multi-channel sources that will use the L/R speaker) and for ambient sounds (rear channels and center not aligned with the L/R audio). I'd like to examine the issue specifically (latency of the C658) and more generally (can the latency be resolved).
What is the latency of the C658 in pass-through mode? This is likely best directed to NAD but perhaps some here have noticed audio sync issues when using its pass-through mode.
The second question is whether the latency can be mitigated. There are two forms of sync issues raised by latency in only 2 channels: (1) Syncing of all channels together when only 2 are affected; (2) Reconciling delays to mitigate audio/video sync b/w outputs (audio & video).
In my setup, I intend to use a pre-pro (Integra 80.2) with Audyssey XT32. With DIRAC turned off when in pass-through mode, would the Audyssey XT32 (ran after inserting the C658 into the chain) correct for any such delays? My initial hunch is that it should - any delays in the L/R caused by the C658 are akin to increasing the distance of the L/R (making them sound further away than they really are). Since Audyssey measures and adjusts for distance, I would assume Audyssey would mitigate the latency caused by the C658 (or MiniDSP). Thus, Audyssey should address the problem of the L/R channels being, initially and without correction, out of sync with the other channels (which do not go through the C658).
With all 5 channels now synced via room correction (assumption concluded from above), would this introduce audio/video sync issues that have to be addressed separately. I think the answer depends. If the source goes through the AVR/prepro to handle both audio & video, then there shouldn't be any independent syncing issue since the AVR/prepro handles similar syncing of the room corrected audio/video in the normal course. If the source goes to the display separately or directly (rather than through the AVR) there would be the same sync issues inherent in such a setup, although more elevated than normal (from larger than normal delays to account for the L/R latency). Under such a setup, one has to address sync issues in any event - adding the C658 would not create a new problem.
What was initially a question has turned into a thought experiment in which I have concluded that any latency created by the C658 are of no consequence if the source audio/video is passed through the AVR/prepro that uses room correction. Accordingly, it should be a non-issue for watching TV/video. The same cannot be said for those using their system to videogame. The added audio/video latency created by the AVR/prepro to account for any pass-through latency would likely be noticeable.
I'm happy to be corrected as to any of my thoughts on the subject.