Bluesound: 48KHz Down Sample Problem [Resolved in BluOS 2.10.9]

Bluesound just released a FW update. Not sure what it fixes, but it’s clear it doesn’t fix the 48KHz max limit.

Was about to post exactly the same comment.

I’m getting more and more puzzled that this problem hasn’t been fixed given that it would appear to be caused by a setting in the Bluesound software - but only for some products (Flex, Pulse Mini, Pulse Soundbar). I know that Node 2 os OK and believe that PowerNode 2 and Pulse 2 are OK. For the affected products there’s a line (raat only_48000=“1”) in the Bluesound software (the software for the speakers, not the BluOS app). This would appear to make Roon think that 48K is the only sampling rate that the speakers can accept.

When I first raised the issue Brian replied to say:

That flag is not set by us (or known to us). The sample rate in Roon is happening because the device is reporting to us that it only supports 48kHz via RAAT, as you noticed in the logs. We would never add extra processing steps for no reason.

If I were in your shoes, I’d put aside the 48k issue until Bluesound is ready to comment, as we’re not in a position to shed light on their choices. We have brought it to them (not their support team), and they will respond when they’re ready.

Last I heard from Bluesound (a week ago) said:

You are now asking the questions our Engineers and our Partners Engineers are asking and trying to figure out themselves.

We are sorry if it sounds like a lot of finger pointing, but in actual fact its a lot of, gee I’m not sure how your software works with our hardware, are the two getting most correct answers to questions they may be misunderstanding…

Both organisations continue to look for the root causes and best solutions.

Thanks for your patience…

Two months on … frustrating!!!

Can Roon provide any enlightenment? @support @brian @mike

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Heck. What a merrygoround.

I’ve managed hardware/software projects for embedded products before and I’m scratching my head as to why this is so hard to find as bluesound products should have pretty much the same hardware/software platform for the digital section. So if one product has the problem, all should. Guess there must be something non-obvious.

Getting close to the point where I’m going to dump bluesound and go back to sonos. No right or wrong, but I think I’d rather have trailing edge hardware and a much more feature rich software package (access to radio stations on napster and single push of a radio button to play for example), significantly better software quality (zero problems with sonos - lots of bugs with bluesound), and real customer support.

This is sad. Bluesound is losing sales becasue the product does not work as advertised and Roon doesn’t have any fully functional RoonReady speaker endpoints.

I’m not happy about how long this issue has been open either. We’ve contacted Bluesound about this again today, and will be working with them to hash out a path forward.


Thanks @brian - good to know that Roon are being proactive on this.

Despite the frustration around this issue I’m still glad that I changed from Sonos to Bluesound - better sound quality, ability to control from any IR remote (e.g. a £5 one), preset buttons which can be assigned to internet radio stations (much easier than reaching for iPad first thing in the morning). There’s also the bonus of being able to make the Flex portable (rechargeable battery pack). Ability to group with other RAAT endpoints is also important for me.

At least Bluesound are happy to work with Roon - from what I read the Sonos integration in Roon has been done without any support from Sonos. Sonos is limited to 48K (and 16bit) anyway by hardware limitations I believe. I am hoping that Bluesound’s reticence to explain why some products are limited to 48K is not caused by hardware limitations that they don’t want to admit.

What I find difficult is the lack of any real explanation about why only some Bluesound products are affected. Roon are normally very open and transparent about any issues so I guess that, in this instance, their hands must be tied by some sort of NDA with Bluesound.

The explanation should come from Bluesound since it’s an issue at their end. The fact that the 10.2.6 player update doesn’t contain a fix means that they are not able to solve it (yet).

That’s encouraging to hear.

This is what I read on the Bluesound forum regarding the latest update:

Microsoft Groove has made changes to their login authentication procedures. As a result, we have updated all BluOS Players to meet their new security requirements an ensure a continuation of service to all MS Groove and OneDrive users of Bluesound after March 31st of this year. MS Groove users may have to log out and log back in in the More Music Menu.

Was this fixed in Roon build 216?

Can’t see how any change in Roon can (on its own) change this - there is a setting in the OS for Flex, Mini and Soundbar that forces Roon to see 48K as the only sampling rate available for these speakers.

Any news @brian on your discussions with Bluesound?

There has been good progress on this since reaching out to them two weeks ago–but not quite ready to share the details yet.


Sigh. So Bluesound still isn’t quite RoonReady.

Good news that there are signs of progress - it must be a more difficult problem than originally thought. Despite the 48K issue I’m pleased with the Bluesound products - integration with Roon is much better than alternatives (e.g. Sonos) - just hoping that it’s not some sort of hardware limitation in Flex / Mini / Soundbar that is causing the 48K issue.

Great to hear.

Update from Bluesound …

Post by AndrewH » Mon Apr 17, 2017 9:10 am

We have not fully responded to all the questions arising from the Roon/BluOS implementation because we wanted to take the time to check fully with the design team after they discussed it all through with Roon to create the best user experience. Some clarifications are in order and here is a note from Greg Stidsen our Director of Technology and Product Planning that we found very helpful:

“The Bluesound (BluOS) ecosystem is built completely on our company’s desire to differentiate our solutions with the ability to manage and play or stream high resolution music files. Our belief is that offering products with easy access to the benefits that high resolution audio brings will only increase the enjoyment for music lovers and enthusiasts worldwide.”

“To clarify things, our BluOS protocol manages, via wireless or hardwire connection, music files up to 24/192 and allows these files or streams to be accessed anywhere in the home, grouped together, or played individually in various zones. The first four products introduced by Bluesound, our NODE, POWERNODE, VAULT and PULSE 2 (and original PULSE) accept files up to 24/192 and maintain the native sample rate until the DAC stage where signals are generally upsampled from Pulse Code Modulation, to Pulse Density Modulation or Pulse Width Modulation, depending on the specific DAC design employed.”

In the Bluesound Gen 2 family our design team continued to challenge ourselves to hit even more accessible price points and categories. This led to our launch of the PULSE MINI, PULSE FLEX and more recently the PULSE SOUNDBAR. To enable us to bring our high resolution music protocol to these price points and to optimize the performance in such compact designs, we utilize advanced DSP algorithms to linearize frequency response and optimize acoustic output and dynamics of the system. Paul Barton, Chief Designer of PSB Speakers and key contributor to our Bluesound acoustics design team, provided the following commentary on what this means for these products:

“In the three most recent Pulse designs (Flex, Mini, Soundbar) we have carefully balanced performance with cost by focusing our resources on the most important things. These models are completely closed designs enabling control over every aspect of the signal flow from the input to the transducer (woofer and tweeter) output. Since the weakest link in any sound reproduction device is the transducer, we have paid special attention to the woofer and tweeter designs and enhanced them with custom DSP control to improve all aspects of driver performance. Taken together, this advanced acoustic platform results in the exceptional musicality of the Bluesound systems. By operating the speaker DSP in these three models at 24/48 and the digital switching of the amplifiers at 384Khz PWM (Pulse Width Modulation) we achieve an optimal balance between performance and cost.”

In a new BluOS software release issued today (2.10.9), we have updated the Roon/BluOS implementation so that BluOS devices receive the native file format. We apologize for not getting that quite right in the first iteration of Roon Ready, and for any confusion this may have caused.
We have captured all of this information in an FAQ on our website at the following link: … 5005574428

Thanks for #LivingHiFi


That’s rather great. An interesting read too.

Here’s how I read this. Bluesound didn’t have enough signal processing bandwidth left over on some their products to handle the extra overhead associated with the Roon endpoint software. This is not necessarily a bad engineering decision as one always tries to optimize cost/performance trade-offs, particularly for consumer products. It seems clear that Bluesound knew about this performance limitation a long time ago as the products affected had higher bit rate capabilities disabled when they acted as roon endpoints. It sounds like they had to do some significant rewrites of the code in order to handle higher bit rates. The real issue as I see it is they just released the code, didn’t bother to tell any of their customers about the limitations, and then kept quite about it for 2.5 months before coming clean. One of the many reasons I won’t be buying Bluesound products in the future.

I can confirm 2.10.9 fixes the down-/upsampling problem. My Pulse Mini is playing at 192/24 just fine now. :slight_smile: