Right now, they all get the same stream. That’s going to change in the future.
Doing this “right” requires some of the same infrastructure that is needed for DSP features (since most of that stuff–speaker correction, eq, up-sampling, etc) is also per-room.
There is one small downside to doing the right thing: it puts a bunch more stress on the core if the streams that are needed are very different.
Over the last few weeks, a major rewrite of the drivers for the Pi’s onboard audio has been going on. The good news is that audio quality (while still not comparable with a good DAC HAT) has much improved – resulting in way lower noise levels.
You can find the dirty details over here, but it basically comes down to upgrading firmware & kernel though rpi-update. If you have never used this before, you will need to install it first:
sudo apt install rpi-update
After running ‘sudo rpi-update’, your firmware & kernel will be updated (currently to 4.4.8). Finish off by adding an extra line to /boot/config.txt:
audio_pwm_mode=2
(Make sure that ‘dtparam=audio=on’ is also present and not commented out).
After a reboot the new audio drivers will be loaded and operational.
Note that these are still limited to 48/16. The development branch has patched drivers that accept 192Khz, but still truncate to 16-bit. You can install the dev firmware/kernel by issuing:
sudo BRANCH=next rpi-update
As always with using development versions: proceed at your own risk and be careful out there. Though generally, you’ll be fine. Mostly. 
Thanks for the update Rene, will try that one when I try my linear PS.
I’m assuming when you instigate BRANCH=next, its the whole OS not just the audio related bit?
It will replace the kernel + firmware files. There won’t be any difference if you are still using your Hifiberry DAC though – it is already using its own device tree overlay, seperate from the Pi’s on-board audio.
Hi,
trying to get roonbridge working with my soekris DAM1021 DAC 
i can`t get i2S running with roonbridge, picoreplayer is working fine, in config i enabled i2s but no sound over i2s, hdmi and 3.5 jack is working fine…
Help, i`m an linux noob 
Marco
It works ! 
i have “magic fingers”
dtoverlay=hifiberry-dac was the key after several updates & driver reinstall…
Marco
Quick update.
I had a few mins tonight, so put the 5V eBay LPS on the Pi.
Ok, so I’d not actually had chance to test the theory that an LPS makes a difference to audio quality on a Pi, but I was inclined to believe it, so had bought one a while back in anticipation of Roon Bridge. However, I wasn’t prepared for the fact that it would not only improve the internal analogue out noticeably, but it also removed the speaker buzz on the hifiberry out! Result!
So in fact, the problem was the cheap power supply I’d bought with the Pi - which didn’t just make it sound bad - it was truly awful. Unusable. So you heard it here - check your power supply for any issues - a cheap SMPS or phone charger type thing may well be useless for a Pi who’s primary role is audio. In fact, even using the cheap Pi supply as a charger for the jambox made the jambox buzz!
Needless to say the LPS was a worthwhile purchase and shows its always good to experiment. I was pleased! 
(edited to say for reference this is the ebay link for the LPS I bought here. It took a good few weeks to arrive from China, but was well packaged and seems well made. How it compares to better/more expensive ones I’ve no idea and am certainly no expert on LPS’s. There’s always the slight worry about safety too, but I honestly don’t know how much safer a super-cheap factory made phone charger or whatever with as CE mark is - perhaps someone else can shed some light on this?)
I didn’t have time to try the kernel update - another time.
Since it’s now useable I set the hifiberry to DSP volume and that made for a much more pleasant volume control too. Not the perfect scenario but a good workaround.
I even decided to make a hole in the case. Measured it. Used a slow metal drill bit (its the only vaguely suitable thing I had), took my time (just holding it in one hand against a piece of wood) and hey presto. Perfect hole! Very neat. Except when I tried to put the case on I’d apparently measured it wrong so had to do another one. Which was too close to be ‘clean’ and slipped into the first hole. No problem I just bodged it with the drill, scraping about until it was big enough. Excellent. But no, still didn’t line up. Repeat. Nope, not quite! After four goes, I got out a file and opened it up a bit. Finally!! A bit messier than planned (but still not bad) it ‘lined up’ with the socket ;). So I could finally close it up. Except, actually the case isn’t big enough around the back, so it doesn’t clear the board and won’t shut fully anyway. Bo*****s!!!
Oh well, I just sort of jammed it on and will get another case at some point. Leson learnt.
So now it’s moved upstairs with linear LPS and jambox on battery and it’s an experimental bedroom speaker. I definitely want something nicer looking for up there, so will probably be an AirPlay thingy ultimately, but for now…
To be continued…
It just occurred to me that maybe it wasn’t the linear aspect of the PS that made the difference, and perhaps a better quality SMPS would have done the same job. Who knows. If so, maybe the ifi is also a good bet - I’ve bought one for something else but its 9V so I can’t try it on the Pi…
It’s actually a question of noise. The very good ifi iPower supplies are switching power supplies but use the newest generation of power regulators that have microVolt noise levels. If you are handy with a soldering iron, you can build your own (http://www.diyinhk.com/shop/audio-kits/88-08uv-ultralow-noise-dac-power-supply-regulator-91215v-15ax2.html). The down fall of regulators is that if your current draw is too high they breakdown or fail (overheating).
On my Pi setups I use batteries for power, cheap and very quiet. I plan to experiment with the Hifiberry DAC+ Pro in the next while and see how it behaves with a switching PS for the digital stage and battery for the analogue section.
Updated Roon Bridge on the Pi last night to the latest, and this now works a treat. Switched from DSP to device volume, and was immediately able to control it as expected…
the device volume control doesn’t seem to work on my Hifiberry digi+. the latest build of roon server is installed …
The Digi+ is a digital board and as such does not have volume control. VC would need to take place in the digital domain, resulting in a non bit perfect signal.
If you really need Software VC, you can set Volume Control Mode to DSP Volume in Settings > Audio.
ok got it … thanks! that’s what I assumed … the DSP volume is what I used from the beginning. so I will continue to use it that way.
This might have been covered elsewhere, but it would be better if device volume wasn’t reset to 100% after reboot! Bit of a shock!
Not only that but the volume control on the iPhone was completely unresponsive for the first 5-10 seconds. It popped up but wouldn’t move. Paused playback. Adjusted it. And restarted. Then things were OK.
But that’s the second time I’ve been officially told off during this experiment.
Had the volume issue again last night, but at least I was ready for it being 100%, so no one got annoyed!
It seems its not the volume control being unresponsive for a specific time, but that it wont ‘slide’ down from 100%, it has to be touched somewhere else (like say 50%) first, and then you can slide after that. In the panic of sound blasting out at 100% the first time round, I didn’t really get to perform this more scientific test!
I’ve just realised my iPhone wasn’t updated to the latest Roon, so this might be the issue thats been fixed already - will test tonight.
Interestingly I’ve now found that when plugging the jambox into the mains again, even with its power supply, I get a very sight buzz back. I’ve ordered a different 3.5mm jack cable, and a different micro usb cable to see if it improves things. Ultimately its going to go, so it’s just a temp fix.
I’ve now sold my spare floorstanders on ebay (for a ludicrously low price sadly), so will use the funds to replace the jambox ASAP. At a nice hotel I was at for the weekend they had Marshall Stanmore (or maybe Acton, damn, wish would have noted the model down), speakers in the rooms, and I kind of liked the retro feel. It sounded average but OK really, I even wonder if they added a bit of extra hiss for effect…
From the release notes:
Fixed an issue dragging volume control
There’s hope for you,sir.
Life’s too short for waiting. Ordered a white “Marshall Acton” for the bedroom, to replace the Jambox and be paired with the Pi/hifiberry. Whether it’s the one I used at the weekend, only time will tell…
https://cdn.shopify.com/s/files/1/0497/4037/products/acton_07_1024x1024.jpg?v=1417770020
The B&W A5 was also on the list but when it went to a vote it didn’t make the cut on aesthetic grounds, and because we’ve heard the Marshall already so know we can live with it, and its kind of cool.
Longer term I may still try and find a more bedroom friendly thing (alarm and clock and that sort of jazz) in which case it would move to the kitchen or elsewhere.
What I liked about the Marshall is the very limited functionality - no remote, no Airplay, no other inputs apart from bluetooth which I never use at home anyway - which kind of makes it’s mission clearer in the Roon ecosystem. It’s also got a decent standby mode which meets the eco credentials (one good thing the EU has set underway IMO). And you’ve sort of got to like the curly audio lead that will wing its way form the (hopefully hidden) Pi.
So, for now, still wires and boxes and 2 plugs, but at least one of the ones on show is curly and a bit bling. OK that’s a step too far, but…
(incidentally if you’re looking at these the slightly bigger one - the Stanmore - also has RCA and optical inputs.)
Looks nice! is the tattoo job included or optional?
Actually I was assuming it was all-in, including the nail polish.
Otherwise I think I’ll have good grounds to send it back under false advertising…
