Feature Request - Negative delay for Sonos Port

 When you are playing Dolby Atmos on a Atmos capable room then group in a non-Atmos capable room there is a short muting of the sound.  I think if there was a notification warning of a possible glitch using a delay compensation for a Port users would accept that one time flaw in the music flow.  Group the devices before the party starts.

I’m sure Sonos has far more data on what their users will or will not accept, not to mention what they themselves consider to be reliable streaming performance of their own system. 

Exclude Sonos from use case for a moment, how would a multi zone AVR handle this, if one zone is using a DSP and another is plain stereo?

Could this feature possibly already be implemented on the AVR to cater for this DSP delay, and use the second AVR zone as source into Port (Sonos)?

Some AVR’s will not convert HDMI audio to analog.

In my case, disabling dsp means losing my sub, and the actual speakers are too thin to maintain audio fidelity without the sub integration. Even in pure direct there is enough delay to cause drum beats to sound like an echo when paired in sync with another room.

Hi ​@PhAzE 

Welcome to the Sonos Community!

Thank you - I've marked this thread as a feature request and it will be seen by the relevant teams for consideration. Keep the ideas coming!

Please note, however, that for the reasons listed above, and for others, I think this very unlikely. It’s not up to me, of course, so your feedback will be passed on.

One point that was not previously mentioned is the use case where there are multiple ports/3rd party amps in the system, where each amp has a separate delay.  In order to achieve actual sync across the whole system, you would need the non- port speakers in the system to delay to the lowest common denominator delay, and each Port delay corresponding to the particular amp they were connected to.  Or, have the amps add delay if that’s an option.  It can get complicated rather quickly.

That said though, if Sonos were to do this, I think it would be better  to have delays in the system set regardless of any current grouping.  In that manner, you would not getting any skipping when the group membership changes.  

I was actually coming to post that second point today funny enough. Yes, making it a system wide permanent delay would eliminate the skip/jump versus doing it dynamically.

For setups with multiple ports, there would need to be a bit of calculation involved. Say you have 3 ports with these delays set:

Port 1: 80ms

Port 2: 120ms

Port 3: 35ms

The system would need to add the largest delay of 120ms to all speakers, but the other ports would only get max delay minus their delay to keep them all in sync.

Port 1: 120ms - 80ms = 40ms delay added

Port 2: 120ms - 120ms = 0ms delay added

Port 3: 120ms - 35ms = 85ms delay added

Non Port speakers: 120ms delay added

Agreed.  Lowest common denominator.

How would you handle cases where the 3rd party amp is actually the audio source for the Sonos system, not just the sink?  Your non port speakers are now 120ms, in addition to the normal line in delay (60 ms),  behind the amp that is the source, or 180 ms.  If the line in source is on port 2 you’re actual needed delay time is going to be the new ‘slowest’ port + the line in delay, or 85 ms + 60 ms = 145 ms.  Maybe that doesn’t matter to you, but since the line in source is often going to be acompanied by video, it matters to many.

Given the absence of tape-loops and/or line-level outputs (not a pre-out) on modern systems that becomes a problem.