Zone Grouping Delay to keep devices in sync... seriously? RAAT should do it!

Hi there. I am testing ROON multiroom with some devices. Currently with a Lumin D2 and Bluesound Pulse.

The devices where not playing in sync. Looking at the device advanced settings I found “Zone Grouping Delay (ms)” setting and added a 10ms delay to the Pulse. Much better sync now.

So far good. But if I change the settings of the Lumin (it has quite a lot, eg allowing to upsample some formats) I am finding that changing these settings requires me to change the delay. Now I can setup the Lumin to handle different rates with different settings and then - guess what - no single delay will work.

Now seriously, Roon claims it did not settle for existing multiroom protocols since these all had limitations, and instead decided to create RAAT which is supposed to do better. With Airplay 2 I have never experienced devices to be out of sync. This seems like a pretty bad protocol implementation to me.

Every device should be able to tell ROON about its internal (current and format dependent) processing delay via RAAT. The ROON software should then take each devices current processing delay into account to make sure all devices are always in sync. A great implementation is always user friendly and hidden to the user.

With my Bluesound devices, I’ve found that the best way to set up groupings is in the Bluesound application (not Roon). Once I have the Bluesound devices grouped, then I can go into Roon and add a non-Bluesound device to the group. But in the past, if I tried to group 1 BS and one non-BS device directly in Roon, I’d get sync problems. For some reason. YMMV.

You’ve almost certainly done this but it’s worth making sure your Bluesound firmware is updated - there is a long and torturous history of sync problems with Bluesound devices and Roon but the situation seemed significantly improved of late.

I also have a Lumin D2 and BS Flex (as well as a few RPis) which currently sync perfectly, so suggests something else might be going on here. I should say that I do all my upsampling in Roon, rather than the D2 - @wklie would be able to clarify whether that has any relevance here.

I think you should start by turning off any DSP in the Lumin and then grouping the zones. Also, if this doesn’t resolve synchronisation try setting ‘Clock Master Priority’ so the Lumin is higher than the Bluesound.

Peter Lie @wklie may offer better advice on grouping Lumin with other products.

Thx for the replies so far. I was not aware of this „Master Clock Priority“ setting, I will sure try it out.

But remind the main point of my post is actually that my expectation for a good multiroom protocol is that it handles such cases seamlessly - not requiring user to tweak delays and such.

Ps: all devices have latest firmware

Pps: just in case Peter reads this: guys, I have this Lumin D2 on loan since yesterday … and I am already addicted to it. So „organic“ sounding. Beautiful!

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I suggest you read up on RAAT. I have no issues with timing across many zones and different devices. However, if you are using DSP on one device then I’m not surprised you and having difficulties; processing takes time and this may account for the delay. By setting the Clock Master Priority, Roon will prioritise the Lumin (normally default settings work just fine.)

It would be helpful if you posted details of your network and how each endpoint is connected.

Martin, I will test the master clock setting and report. But read my post carefully, will you. Your suggestion I read up on RAAT is missing the whole point of my thread. DSP takes time, so each device could potentially have a format dependent changing delay. My expectation is that a good protocol handles this seamless to the enduser - so all these settings, delay, master clock, should not even be there in the first place.

Roon is supposed to give us a great user experience. When I see these settings, it smells like bad not good UX. Feel free to disagree, but accept my opinion. It is now the third time I am writing this.

Airplay 2 has no single setting, nor does Apple suggest me to read it’s protocol. And yet I have found no sync issues with it so far. That’s all there is to say. Good technology hides it’s complexity from the user.

I don’t think any other user could possibly add something useful to this discussion. It would be interesting to see the response from someone at Roon though.

Please disable Lumin internal re-sampling features when using Roon. Roon DSP Engine can do many more types of re-sampling than what Lumin does internally anyway.

Airplay 2 is simple in comparison to Roon it allows no External DSP or signal processing and has little deviation in sample rates.

Roon allows this on any RAAT endpoint that’s is synced in a group but these parameters are not fixed and are all user dependant and delays in processing are Roon core dependant plus network overheads, temperature etc. Roon has to allow controls to allow users to change delays to account for these unknowns. There is no way this is going to be consistent across devices as it’s not the device doing it.

I agree that any internal DSP etc on a device should be accounted for in RAAT, this may well be already available if the manufacturer exposes it. It might not be mandatory though. Airplay is a well locked down protocol in comparison and they can get away with it as they are a big player.

I think you could be a little more gracious since I am offering you assistance as a community member.

You evidently haven’t understood how Roon or RAAT works. As I said, before start by turning off DSP and then consider prioritising the Lumin so it controls the master clock … it maybe that the Lumin isn’t accurately reporting the delay or the Bluesound has control of the master clock. Remember you are mixing different devices not using Airplay.

You have my apologies for the harsh tone Martin. Sincerely.

Tomorrow I am returning the Lumin D2 I had on loan, for me it is ATM sufficient to know that ROON multiroom can be made to work with devices from different vendors.

Besides the nice UX of ROON, this is a very important feature for me. Since this is for sure also a hobby, locking in to a single vendor is not really fun. I’ve done it with NAIM for the past 15 years. I cannot complain about their kits, especially the newer series have a fantastic feature set and user experience. But it is so much more fun to have kits also from other vendors and still be able to control everything and do multiroom from one single app - in this case ROON.

I still believe this is all too complicated and I wish that future updates, enhancements to the protocol, more strict certification, allows to simplify things for the end user. I can setup ROON, with the help of the community here. But can my parents also? Definitely not.

Again, thx for the helpful tips. It can only get better :slight_smile:

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Hello @Moli,

We expect Roon Ready devices to compensate for any delays introduced by their internal signal processing. If that is not happening, it should be remedied in the device firmware. We will check this configuration using hardware we have on hand, and then get in touch with Lumin if we can replicate the problem.


This sounds excellent. It is exactly what I would expect from RAAT/Roon Ready certification - the fact that there are so many settings to tweak things, and that these actually work, is what is confusing.

Keep up the good work at Roon. You main asset is user experience. Make sure the Roon Ready certification is as strict as possible. It might lead to a lower rate addition of that nice partners logos, but if you fail here, then Roon Ready is meaningless because the user experience suffers. And what is left of Roon if the UX is not the best?

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