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Since this has come up again with recent Apple news of release of HD music, I thought a separate thread on this subject might be useful in general.

I will start with a link to a recent thread where this is seen to be a problem on Sonos:

https://en.community.sonos.com/troubleshooting-228999/sonos-speakers-cut-in-and-out-when-playing-hd-music-6858735

I don’t have or plan to have HD music in my home, I don't believe it add to heard sound quality. But I have seen problems in the past with grouped wireless play while playing uncompressed files from Sonos line in jacks. And the link above is a case of someone having problems playing Sonos HD radio. In grouped mode as well as on a single speaker, where the Sonos response has been: ethernet wire the units to the core network.

By all accounts, Bluesound has the same problem. And so do many others I thought till yesterday...when I read here that Roon does this with no trouble at all. Now, I don't know Roon, except vaguely, to know that it is server software that piggy backs on to existing Wifi audio hardware. So, how Roon can do this when the underlying audio hardware cannot, is the first question I have.

I also think that these issues are what held Sonos away from HD all these years, while they kept saying that better heard sound quality from HD isn't supported by science. Now they do have some kind of HD on their S2 generation systems, have they addressed these reasons of unstable wireless music play that have been a concern in the past? And which, if one sees the link, are still a concern.

Finally I suggest that for the purposes of just this thread, discussions should not get diverted into the  “is HD audibly any better” subject. I only said what I did above to declare that I have no personal experience of HD streaming.

The linked thread deals with Tidal and Sonos Radio HD. Both stream to Sonos in conventional CD/Red Book 16/44 resolution. The use of the ‘HD’ label in this context is not ‘Hi Res’, it’s marketing spin.

Sonos has never ‘stayed away’ from Red Book. I’ve streamed CD FLAC across a multiroom system for nigh on 14 years without any major issues.


In that case, the linked thread isn't relevant, I agree, and there is something else that is causing the problem. But it does highlight the bs surrounding HD, where marketing spin can casually attached HD to anything it feels like. I mean, why not to 320 lossy next?

My wifi network is from a 2011 vintage Apple Time Capsule, with Sonos on Sonos net via a Bridge. I too have not had major issues using ALAC CD( lossless) rips on a local NAS either on a single speaker or in grouped mode. Once the IP address reservations were done. But I recall facing problems using uncompressed mode on Sonos line in jacks, in wireless grouped mode. This, when the only options offered for line in were compressed/uncompressed/auto, and one could not change the buffer or delay settings.

So, question: is the network burden for uncompressed line in much more than that for ALAC CD rips? If so, how much more in comparison is it for true HD - say 24/96 material?

Other questions: will HD - and I now refer to 24/96 and denser - streams on Sonos fare better if the home WiFi is the latest and greatest? Without using Sonos net? And, if using Sonos net, does it matter how good the underlying WiFi is - as in will it matter if a brand new router is used instead of a ten year old one like the one I have?

Also, will S2 hardware do better on this front than S1?


I just took a quick look at Wikipedia and found this:

High-resolution audio (High-definition audio or HD audio) is a term for audio files with greater than 44.1 kHz sample rate or higher than 16-bit audio bit depth. It commonly refers to 96 or 192 kHz sample rates. However, there also exist 44.1 kHz/24-bit, 48 kHz/24-bit and 88.2 kHz/24-bit recordings that are labeled HD Audio.

 

As can be seen, this excludes CD formats from the definition. But it is otherwise so wide, that this thread will be all over the place! And of course per Sonos/Tidal, and Amazon too I think, it also includes CD quality….


So, question: is the network burden for uncompressed line in much more than that for ALAC CD rips?

Yes, on two counts:

  • FLAC/ALAC streams in the region of 600-1100kbps. It’s compressed (losslessly). Uncompressed Line-In streams at 1411kbps (16*44.1*2), i.e. PCM stereo.
  • Uncompressed Line-In is treated as time-critical, with (usually) a very shallow buffer. Depending on the source streaming a file will result in much, often all, of the file being buffered by the player.

 

If so, how much more in comparison is it for true HD - say 24/96 material?

Multiply the above FLAC/ALAC bitrate figures by 3. But, again, as a file this will be heavily buffered upfront, to ride out network perturbations.

 

Other questions: will HD - and I now refer to 24/96 and denser - streams on Sonos fare better if the home WiFi is the latest and greatest? Without using Sonos net?

Quite possibly, especially the latest players which can connect to 5GHz.

 

And, if using Sonos net, does it matter how good the underlying WiFi is - as in will it matter if a brand new router is used instead of a ten year old one like the one I have?

No it typically doesn’t matter. Other than in a system with Move/Roam (or when using, say, Airplay), the only traffic on the WiFi is for control.

 

Also, will S2 hardware do better on this front than S1?

Undoubtedly. The later players have a much better radio, and as I say some can now connect to 5GHz WiFi.


 

  • Uncompressed Line-In is treated as time-critical, with (usually) a very shallow buffer. Depending on the source streaming a file will result in much, often all, of the file being buffered by the player.

 

Excellent answers all, thanks!

With reference to the quoted, does this mean then that my experience with uncompressed is not really relevant to the HD streaming subject, since the latter can resort to buffers?


 

  • Uncompressed Line-In is treated as time-critical, with (usually) a very shallow buffer. Depending on the source streaming a file will result in much, often all, of the file being buffered by the player.

 

Excellent answers all, thanks!

With reference to the quoted, does this mean then that my experience with uncompressed is not really relevant to the HD streaming subject, since the latter can resort to buffers?

Correct, other than the fact that a network that’s heavily choked won’t be able to support either. There has, after all, to be a minimum average throughput equivalent to the source bitrate. TANSTAAFL


 

Sorry, I made a mess with this post, I wanted to digress to ask this question with reference to your statement: Uncompressed Line-In is treated as time-critical

Why is it treated as time critical?


 

Sorry, I made a mess with this post, I wanted to digress to ask this question with reference to your statement: Uncompressed Line-In is treated as time-critical

Why is it treated as time critical?

You can’t send Line-In audio data until it’s been received by the encoding player.

The default buffer size is 75ms i.e. sufficient to absorb packet jitter across the average home network but still small enough for many people to feel like it’s ‘real-time’. 

There are options to increase the Line-In delay where delivery doesn’t have to be quite so ‘real-time’, such as for a turntable.


You can’t send Line-In audio data until it’s been received by the encoding player.

The default buffer size is 75ms i.e. sufficient to absorb packet jitter across the average home network but still small enough for many people to feel like it’s ‘real-time’. 

There are options to increase the Line-In delay where delivery doesn’t have to be quite so ‘real-time’, such as for a turntable.

This works for me just fine actually, for a TV that feeds audio to a Connect Line in and thence to a group of Sonos speakers. The small buffer allows for lip sync to not be a visible issue. All I needed for this to work flawlessly is to wire all the Sonos units to the core network, and it works brilliantly.

End of digression.


This works for me just fine actually, for a TV that feeds audio to a Connect Line in and thence to a group of Sonos speakers. The small buffer allows for lip sync to not be a visible issue. All I needed for this to work flawlessly is to wire all the Sonos units to the core network, and it works brilliantly.

A wired connection typically has a sub-millisecond latency. A wireless connection needs to gain access to a radio channel filled with all manner of unwanted other users, some of whom may cooperate in sharing the channel but many will just keep on shouting.


 channel filled with all manner of unwanted other users, some of whom may cooperate in sharing the channel but many will just keep on shouting.

Sounds familiar...:rofl:


Moving on, and since I am not familiar with S2 offerings - Does Sonos already offer the ability to play enough genuine HD material that S1 does not (thereby ruling out CD formats labelled as HD), such that its wireless distribution capability of this material in a stable way to a group of speakers gets fairly tested? Or is that kind of HD offering still to come?

What I am hearing of Bluesound is that for 24/96 and above streams, group play without stuttering needs ethernet wiring of the units. All anecdotal though, so this is just one data point.


Does Sonos already offer the ability to play enough genuine HD material that S1 does not 

It depends on your definition. S2 reads local FLAC/ALAC files in 24-bit, and Qobuz can stream in 24-bit. Both at sensible sampling rates (44.1 or 48kHz). 

Whether or not the lowest 8 bits actually contain anything useful is a different matter. There’s been plenty of evidence of 16-bit content simply being repackaged.


Moving on, and since I am not familiar with S2 offerings - Does Sonos already offer the ability to play enough genuine HD material that S1 does not (thereby ruling out CD formats labelled as HD), such that its wireless distribution capability of this material in a stable way to a group of speakers gets fairly tested? Or is that kind of HD offering still to come?

What I am hearing of Bluesound is that for 24/96 and above streams, group play without stuttering needs ethernet wiring of the units. All anecdotal though, so this is just one data point.


I can get 24/192 streams synced in Bluesound but I do have good WiFi coverage. There is a tech note on signal strength required, this would probably hold true for other hardware platforms. 
 

https://support1.bluesound.com/hc/en-us/articles/201940663-What-should-my-Wireless-Signal-Strength-be-for-best-performance-

 



I can get 24/192 streams synced in Bluesound but I do have good WiFi coverage. There is a tech note on signal strength required, this would probably hold true for other hardware platforms. 
 

 

 

How many players do you usually play at a time when you do grouped play? Are they located in different rooms and if so how do you get them to all get the signal strength needed to sustain stable music play over the listening session?  And is the stream from a local NAS or music coming down the broadband pipe?



I can get 24/192 streams synced in Bluesound but I do have good WiFi coverage. There is a tech note on signal strength required, this would probably hold true for other hardware platforms. 
 

 

 

How many players do you usually play at a time when you do grouped play? Are they located in different rooms and if so how do you get them to all get the signal strength needed to sustain stable music play over the listening session?  And is the stream from a local NAS or music coming down the broadband pipe?

I have three Bluesound players, normally group two but have tested with all three, all in different rooms.

 

I use Plume Superpods, two downstairs and one upstairs. On a “Speedtest” I get a reliable 108Mbps throughout the house on an incoming sync of 110Mbps. 

 

Normally use Qobuz but have a few test files that live on a NAS.


On a “Speedtest” I get a reliable 108Mbps throughout the house on an incoming sync of 110Mbps. 

 

That seems to be the secret; the reliable 108 Mbps across the home. I wonder what the lower threshold for stable HD play is though, because it need not be as high as that, I think. 

Also Bluesound does not have the Sonos net equivalent which is almost certainly an advantage here, because I doubt that Sonos net could deliver you that performance. It may then be that for Sonos to do just as well, Sonos net will not be the preferred option that it is recommended to be today. In the presence of such a WiFi network, for HD streams of the kind you refer to.

Also, do your Bluesound units connect on 5 GHz?


Yes, 5 GHz now, but prior to Christmas when I installed Plume they were on 2.4GHz without issue.


It depends on your definition. S2 reads local FLAC/ALAC files in 24-bit, and Qobuz can stream in 24-bit. Both at sensible sampling rates (44.1 or 48kHz). 

 

By sensible perchance do you mean that which can be wirelessly streamed without stuttering?!

What limitation do you think will come in the way of Sonos allowing play of 24/96 or 24/192 material on S2 hardware in future? I ask because that is what most people till now understand to be HD audio - it will take time for the marketing spin of extending that definition to CD formats to catch on. 


Just to add regarding the Plume Superpods… great WiFi but the software and the features such as parental control / home & away notifications just don’t work despite spending months with support tickets.


It depends on your definition. S2 reads local FLAC/ALAC files in 24-bit, and Qobuz can stream in 24-bit. Both at sensible sampling rates (44.1 or 48kHz). 

 

By sensible perchance do you mean that which can be wirelessly streamed without stuttering?

‘Sensible’ as in covering the range of human hearing, and as a final delivery format.