​@gnahra01 

Ok, in that case I suppose Apple just uses 16/44 lossless cd quality via Sonos API. 

AM Music through Sonos is Max 24/48 kHz. I can see I am getting this from system where an album exists in 24/48 on AM. 

Yes, 24/48 is the max. limit on Sonos. But as far as I know Apple, some time after they introduced lossless on Sonos, switched to a dynamic choose of audio quality depending on network quality, because many people had issues with lossless on poor network performance. 
So my suspicion is, that could be the reason for getting just 16/44 though the track is available on AM in 24/48. 

Btw… how do you check what quality for AM is used exactly via Sonos api when showing „lossless“. Unfortunately there are no different badges like with Amazon Music that show you HD or UHD. 
So I suppose you will have to use a DAC or AVR that shows you what is coming in from a Sonos Port. Or is there any other way?

I’m actually using TVOS app called Bops. Shows now playing info/data from Sonos. 

So Bops app does show more detailed audio information like bitrate than Sonos app itself does? 
In case of Apple Music that would mean Sonos app just shows lossless or not, and Bops app can see from system data if it’s 16/44 or 24/48? This is hard to imagine imho, and if this data actually is provided to Sonos system by Apple, why shouldn’t Sonos app show it!?

Thanks. I’ll keep fiddling around with my setup then. Must be something amiss in the chain somewhere. 

My DAC displays this. So I’m just checking the bit rate directly on AM and then comparing to what my DAC displays when I’m using Sonos app->AM->port->DAC. 
would he strange if it’s my network signal since I’m using the same network to get 24/44 on AM directly. 

Yes it does. And accurately. It uses Soco to retrieve data from the Sonos device. You can even see the quality step-up at the start of a new session with AM from 256 > 16/44 > 24/48. I’m not buying or selling the app, Just offering advice on how to view the stream quality. No need to imagine it or have an opinion. It works. 

​@gnahra01 

Yes, I understand… I just think about possible reasons. 
One imo as said could be reducing incoming quality by Apple. 
Another one might be audio settings on your DAC. 
Or maybe Sonos Port is limited on digital spdif output to 16/44 at non bit perfect output.  I don’t know…

Do you use fixed (bit perfect) or variable (non bit perfect) output?

​@rastallp 

Thank you for screenshot and clarification. 
I definitely will spend the 10€ and try the app on my ATV. 👍🏻

But I really don’t understand why Sonos doesn’t use the information and show it on their own app as it obviously is submitted from Apple and available on Sonos system. 

​@Corry P 

Can you please submit this as an user request? And do you have any idea, why Sonos Port might just put out a 16/44 signal? Would this be visible in some diagnostic data (coming in and going out quality)?

While Sonos does play 24/48 (play, as in decode it to analogue) I’m not sure it also will pass it through to the digital out. Might that be the problem?

Thank you, I appreciate it.

I have tried variable, fixed, and pass-through line-out from the Port.  All result in the same issue (16/44.1).

Thank you.

I thought this might be an issue but others on the forum have said they are able to get 24/48 out from the Port if I’m understanding correctly...thus my confusion.

For what it’s worth…

I tried ChatGPT and it told me that:

• Sonos does not support Apple Music Lossless streaming.

• Apple Music on Sonos currently only supports AAC 256kbps streams, which is lossy and limited to 16-bit/44.1kHz.

• So no matter how great your DAC or speakers are, you're bottlenecked by this integration limit.

So I followed up with Sonos directly - the “bot” confirmed this.  Bit depth is limited to 16 on AM when streaming...not sure how ​@rastallp was able to get 24??  

Apparently it’s an Apple issue, not a Sonos one - Apple restricts bit depth output to 16 when not using the app directly.

And apparently Airplay 2 is limited to 16-bit, so bypassing the Sonos app (and using Airplay into the Port directly) won’t help either.

This also seems to be in conflict with what ​@Sandemannn said awhile back.

Perhaps it’s semantics...I think Sonos is capable of supporting, but AM will not output anything better than 16-bit when not using it’s app natively...and if you try and use Airplay2, the bottleneck shifts to that.

https://support.sonos.com/en-gb/services/apple-music

Don’t assume ChatGPT will give you correct response, it is reading lots of incorrect information posted in public forums (including this one) to compute its responses.

Yes, seems Sonos Port doesn’t do a bit perfect passthrough, but renders to its own digital output format. 
 

There they are just talking about „lossless“. No further information of any details about the format. 

Thank you… that imo underlines the suspicion Sonos Port does output its own digital format. 

Hi ​@Schlumpf 

Not without a dedicated thread being made for it, no. Please feel free to do so, however - making it clearer what the actual request is, please.

My documentation says that Port will output 24bit @ 44.1Khz on the coaxial digital output. So, my response to your question has to be “user error”. The output parameters should match the inputted stream.

I hope this helps.

Thank you ​@Corry P 

I‘m going to create an own thread for my user request. 👍🏻

So Ports digital spdif output format is max. 24/44 or less as for example 16/44 is coming in, port just puts out 16/44!?

That helps! 😎

As a follow up, the bots seem to have been redeemed.

I spoke with Sonos directly and Apple Music does NOT output 24 bit quality via a 3rd party app like Sonos.  

So the limitation is from Apple’s side, not Sonos’ side (as other have said the Port can output 24 bit quality, which I’m sure is true, but that’s not the issue in this case).

I was told only Amazon Music will send a 24 bit signal through the Sonos app.

While I’m disappointed, I hope this helps clarify.

Through the port?

Yes.  But I don’t think the Apple Music output limitation is tied to the port.  My understanding is that Apple limits output sound quality to 16 bit regardless of where it’s being output to, if using a 3rd party app (which is what I am doing when I am using AM through the Sonos app).

The port itself is capable of accepting and ouputting 24 bit audio, but it’s Apple Music that is the roadblock.

The other service next to Amazon Music definitely providing 24/48 is Quobuz. 
 

But regarding to Apple Music either the information from support or the official Sonos info page is wrong. 
https://support.sonos.com/en-us/services/apple-music

Infopage says up to 24/48. 

So though Ports spdif output is limited to 24/44,1 this should be possible. Or maybe Apple Music 24/48 signal can‘t be reduced(resampled) to 24/44,1 but just to 16/44,1. 

Yes, I don’t know what to say about that info page graphic.

All I can say is:

1. From my personal experience I am not getting 24 bit (at least according to my DAC, which is saying it’s only getting a 16 bit signal from the Port)
2. Sonos has told me (via both a live human and their own bot) that Apple Music restricts the quality to 16 bit.

Not sure??  Perhaps just a marketing error on the infopage.