Does Roon ARC Provide Hi-Res Audio?

After some troubleshooting on ARC I got it working with my WifI-6 system.
However, when my ARC app runs on my iPhone 12 Mini and Wifi is on (aka local LAN) ARC on phone is playing back all my hirez files from my local Roon library, but the moment I turn off my phone’s wifi and use my cellular network to connect to Roon core, all I get/can play is lossy mp3. If I try to play a hirez file I get the message ‘Poor Connection’ over 5G……

Is this normal?
Do I need to transcode audio format somewhere?
DSD is converted to PCM inside ARC.

Go to the ARC settings and you can choose quality for wifi and cellular. The default is “Automatically pick best quality”, which means original quality on wifi and compressed ~320 kbps over cellular. If you turn this off, you can pick from these settings:

Depending on these settings, it gets transcoded automatically. (The lossy version is not mp3 though, it’s Opus, Opus (audio format) - Wikipedia)

The quality that is possible over 5G depends on your 5G data rate and latency. Which can be low even if the phone shows that it is connected 5G. Run a network speed test (e.g. https://www.speedtest.net/) to see what you get. However, it’s surely possible that the highest quality does not work on cellular in practical situations. It depends on the 5G coverage where you are

(As your situation has nothing to do with this thread’s original question of hires with CarPlay, it would be good if you could open a new thread if you experience dropout although the 5G speed should be good enough)

Great, worked like a charm :clap:


OMG, that’s your 5G speed? Congratulations, play the lottery as well. Or maybe I should move to Norway :slight_smile:

Riiight :grinning:
My fiber is 1 gig so I guess it suffice :+1:

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I wonder: So although you have these speeds, you get the “Poor connection” message when you have the Auto quality setting or manually choose the Balanced setting for cellular? That shouldn’t happen and might be worth reporting. What do you use for the Core? Do you get dropouts as well or does it play but you still get the message?

Yes, but I fixed it when I abandoned ‘Automatically pick best settings’ - Let’s see if it sticks - so far, so good……

Still shouldn’t happen

I probably spoke too soon.
Just walked my dog and the problem re-surfaced.
Either it worked or I got ‘poor connection’ on hirez material.
When it worked I didn’t experience any drop-outs.

I will make a new ticket for this issue.

Also, when I increase the font size on text on my phone I cannot access the ARC switches deciding the quality, I have to downsize font to toggle switch and decide the desired option.

Whether automotive amplifiers are really “junk” is debatable, but the poor signal-to-noise ratio in a car at speed is not. Even the quietest vehicles (EV or not) have enough road-noise transmission into the cabin to make 24 bit dynamic range completely academic.

Is the HI Res for the dog’s benefit :rofl: :rofl:

I think it’s time for a post in the #support category with all details so that the staff can help :slight_smile:

check this:

does your poor connection happen on 48Khz flacs?

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Yes, he is as picky as my wife! :crazy_face:

Will do :+1:

Just checked the tread and it is very similar (almost identical) to my experience.
Will settings on main Roon app (not ARC) influence this?
In DSP I have set to transcode source to 48kHz because my cinema processor like this better.
In the signal flow ARC says that 96/24 is transcoded to 48/24 and I have not asked for this in the ARC app (setting is ‘original format’ over mobile network).
Having said this, I have a lot of 48kHz flac material in my library, however were I got problems were mainly on native 96kHz during preliminary testing.

I have all my settings to “Original format”, connected DH80S to my Android device.
Played 192kHz. DAC illuminated properly as it should for this sample rate BUT ARC displayed ‘High Quality’ because of the last step: “Output AAudio.”.

I have testet with all kind of formats and it works unconditionally as long as Original format is selected for mobile.
Using my iPhone as the renderer means that everything is downsampled to 48kHz, nevertheless. I reckon this is due to Apple restrictions.

Hallelujah while driving :partying_face:

Infotainment System (CarPlay) and Bluetooth broadcasting via Roon Arc from my cellular.
It is also possible to control Arc via the car media interface:


Similar to my situation, I have my settings set to “Original format”, played 192kHz, and DAC illuminated correctly but ARC displayed “lossless”. However, when I’m using a Bluetooth earphone or headset, it will display “High-Quality”.