Local Devices Music Library & 48khs audio

I’m not sure I understand. Sonos still offers playback of local files from your computer. No need for an NAS, but your computer and drive need to be on. You may need to reset access to your local library, by resetting it up, but as far as I’m aware, it still works. 

It's not local if my device is my phone. I dont want to have to use a computer. That's the stupid part. Why can't Sonos just allow me access to my phone local music library through their s2 app and play from there?

That would make simple and easy sense, right.

I think with a NAS there is no need to have a computer or laptop and I can integrate direct into the S2 app controller?

If the device is your phone, the makers of the operating systems have blocked Sonos (and everyone else) from using it to access data streams from an outside device. It  isn’t, unfortunately, up to Sonos at all. I suspect if the OS makers would allow it, Sonos would be offering it. Which has been discussed in many, many threads since the OS manufacturers have blocked Sonos. It would be easier, in this instance, if the Sonos app was really a ‘player’ on the phone, as then it could ‘cast’ the signal to the speakers. 

Depending on your Sonos device, you can still use either a Bluetooth or AirPlay 2 to send a signal from a player on the phone (not Sonos). 

Not sure you can install an NAS without a computer, but certainly Sonos won’t care. As intimated above, the system (Linux) running on the Sonos reach out to the NAS and play directly through that connection, not through a PC or a phone. The controller device is merely a ‘remote control’ to tell the application running on the Sonos device where to get the data to play. 

Bluetooth and AirPlay solutions won't work because those will resample 48khz tracks. AirPlay 1 is only capable of 44.1khz and AirPlay 2 only streams at 48khz if its a video with audio, not just audio.

If music players on my phone can access my local folder library, why can't Sonos?

Because ‘Sonos’ doesn’t play on your phone. As explained in my previous post, the controller on your phone is merely a remote for the application that runs on your Sonos devices. 

​@Scott Campbell 

As Bruce said the discussion about „playing from this device“ is obsolete since os developers don’t allow access to apps that put audio out on a different device. 
Next point is that a NAS is a different thing than a smb network share. 
Sonos S2 just needs a smb2 share to add a path for the Sonos music library. 
The device where the files are on also can be a USB stick connected to your router, if the router supports a smb2 share option. That‘s the wasy I use it and can play my local audio files with 24bit 48kHz audio quality. 

It’s not accurate to state that Android is blocking access to local devices for media streaming. It simply requires the correct permissions and security settings to be granted.

This is a feature they chose (not were forced) to remove from their app, which I personally find frustrating.

Other apps (such as VLC and BubbleUPnP) work directly on phones to stream local media to compatible devices without requiring a separate media server or additional hardware.

Why don’t I just use one of them, you might ask? Because Sonos only guarantees the 48kHz sample rate when files are played via their S2 app controller.

I have a Telstra Smart Modem 3 with a USB port, so I could plug a hard drive or memory stick into that and enable SMB sharing. Do you notice any lag at all with this when playing tracks?

I might need a bit of guidance on adding the path in the Sonos S2 app.

I've always understood the feauture is blocked for anything else than music/video players. Since the Sonos app does not count as such (it's a remote), the feauture is off limits to Sonos.

Android policies do not block non-music/video apps from accessing local files. BubbleUPnP, which operates primarily as a controller (and optionally as a media server), and X-plore File Manager both demonstrate that accessing and streaming local files is entirely feasible under Android’s rules. This highlights that Sonos’s decision to remove this feature was a choice rather than a technical limitation imposed by Android.

That’s the whole point.  The Sonos app is not “accessing local files”.  The Sonos app is a controller, it’s not accessing anything local.  It’s the Sonos hardware that accesses and plays the file/stream directly (try playing a playlist, then turning off your phone for proof). The app merely tells the Sonos hardware what to play and where to find it.  And if the “where to find it” is the controller device, the Sonos hardware would need outside access to said controller device, which Apple, and later Android, have most certainly blocked. 

So you are incorrect.  This is not “a choice rather than a technical limitation”.