· Roon 2.64 + KEF LS50 Wireless II (fw version: 4.0) Error when sample rate changes
Everything is connected in ethernet.
When an album ends and another one starts with a different sample rate, audio does not start, skips to the next track and finally fails. This happens independently of the server-side resync delay setting (50ms or 2s)
We can see the heavy DSP settings on your KEF speakers, along with the clock sync failure when the sample rate changes.
Please try raising the resync delay to 5 seconds, since 2 seconds may not be enough for synchronization.
We would also like you to try the opposite test: please remove the DSP settings from the KEF speakers, leave the resync delay at 2 seconds, and play the “naked” file.
Please let us know whether playback becomes more stable with either of those tests.
Thanks for your answer,
I just did the 2 tests (one with 5 sec and the other with the default DSP profile on the KEF)
I still have the issue
Also kindly note that I have been playing music with different sample rates for years on Roon without having this issue and using 0ms as resync and the same DSP profile.
edit: I can eventually factory reset the KEF if needed.
With modern DACs, external upsampling often brings mostly no real benefit. Most current devices this days already upsample everything internally to a much higher rate as part of their normal processing. This means that whether you send them 44.1 kHz, they will typically convert it again anyway.
Modern DACs are designed as tightly optimized systems. The digital filters, conversion stages, and signal processing are carefully tuned to work together. When you upsample externally (e.g. in Roon), you may actually bypass or interfere with parts of that internal optimization rather than improve it.
It’s important to remember that upsampling does not create new musical detail. It only interpolates additional data points between existing ones. So while the signal changes technically, the underlying information remains the same.
Looking at your speaker: it resamples everything internally to its own working format. Typically up to 192 kHz / 24-bit when speakers are wired or 96 kHz / 24-bit when speakers are connected wirelessly. And even more importantly: It uses DSP + internal clocking + resampling (ASRC) as part of its core design.
I am quite aware of the internal mechanism of my speakers.
Maybe I didn’t expressed myself correctly.
I play the albums to their native sample rates. The issue is when an album with two consecutive tracks have different sample rates (or the next album in the playlist), it crashes and I have to reboot the speakers to be able to play music again.
I wasn’t having this issue for years and this is what we are trying to fix.
This is not the direction you probably want to hear, but stop doing that. You are gaining nothing. As Stefan alludes to above, you can configure Roon to sample rate convert all audio formats to 24 bit 96 kHz or 192 kHz – whichever is the appropriate internal sample rate for your KEF setup.
This is not a Roon issue; it is a KEF issue. A recent KEF update has introduced bugs for multiple Roon users. You are not the only one affected.
What do you mean by this? Roon most certainly can sample rate convert both local files and streaming content.
If you mean that this solution will not work outside of Roon with Qobuz and other streaming services directly through their apps or the KEF app, well, again, that is a KEF problem, not a Roon problem.
KEF seems to have flubbed its recent software updates. Other users here are reporting dropouts and MQA decoding issues.
While the conversion operates for Qobuz albums, when playing a local album right after (or vice versa) ends up with the same sync issue: 04/23 19:24:00 Trace: [prebuffer] ready 6773760/14112000 (48%) @ 0/256 sec 04/23 19:24:00 Warn: [KEF LS50 WII] [zoneplayer/raat] failed to sync sender clock to endpointKEF LS50 Wireless II: Sooloos.Broker.Transport.ClockSyncResult 04/23 19:24:00 Warn: [KEF LS50 WII] [zoneplayer/raat] failed to sync clocks with any endpoints..giving up 04/23 19:24:00 Info: [audio/env] [zoneplayer → stream] All streams were disposed
I have opened a support ticket at KEF and will post here any relevant information.
edit: @benjamin it seems more erratic than that, it starts failing after 2 or 3 albums regardless of the source.
Again I understand that the issue is on KEF’s side and keeping this thread open to help others and post relevant info from KEF or if any stable workaround is found until they fix.
Experiencing a similar issue: my KEF LS60 Wireless were update to latest firmware 3.0 on April 29. Now, DSD128 or DSD256 streaming (plain, w/o DSP) does not work anymore. DSD64 still works.
