Distortion with KEF LS60's when using iPhone as Roon Remote (ref#95HTQ2)

Support
1

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· Roon 2.65/Roon Rock/Kef LS60’s - hardwired Ethernet/iPhone 17 pro max/ iPad both iOS 26.2.4.

When using iPhone as remote, getting distortion in speakers (sounds like clocking error) pressing pause on iPhone and then restarting on iPad clears problem.

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· Sky TV router, Norton VPN, internet speed approx 70mb/sec

2

Hi @Julian_Mullins,

Thanks for the details here. We are looking into a similar KEF thread, and we want to confirm whether this distortion only happens when sample rate changes occur. That comparison may help us narrow down what is going on with the LS60s.

Please let us know if the issue is limited to sample rate changes, or if it happens in other situations as well. If you can confirm that, we can keep digging from there.

3

I don’t think it can be totally to do with sample rate changes. For instance last night I booted system from iPhone and started track directly from iPhone. Immediately I could hear ‘clicking’ mixed in with music. Pressed pause, restarted track from iPad - no clicking.

I have tried this again whilst typing this and exactly the same is happening. Playing from iPhone - interference/clicking; iPad no problem - very strange.

However I first noticed this on Sunday when I had been playing tracks for 2+ hours and had not had any problems, then suddenly this ‘interference’ became extremely noticeable. This may have started with a sample rate change, I’m not sure. The track where it became very noticeable is in my local library, not streaming.

I hope that helps.

4

Just a couple of updates:

  1. if I boot from iPad also get the distortion, switching to iPhone clears problem after a pause.
  2. The track where the problem is most noticeable is actually a streaming track (my mistake) and is an MQA Format. Have now tried other non MQA tracks without problem. Perhaps this format is where the issue is.

Thanks

5

Hi @Julian_Mullins,

Thanks for the updates and additional info! Based on a fresh Roon Server diagnostic report, you may be spot on with the issue being tied to MQA content.

Every time you pause and quickly resume from the iPhone (or any remote), Roon tears down and restarts the RAAT stream to the KEF LS60.

During each restart, the MQA authentication has to re-establish itself in sequence: authentication → Roon core decode → LS60 renderer.

The logs show this happening correctly most of the time, but on a significant number of restarts (72 occurrences of IsMqa=False in the logs) the handshake completes out of order, the LS60’s internal MQA renderer fires before it receives confirmation that the upstream data is actually valid MQA.

The LS60 then tries to render what it thinks is an MQA-encoded 88.2kHz stream internally to 192kHz, but the data isn’t properly authenticated yet, producing the clicking you hear.

This is compounded by 24 separate RAAT__SOURCE_SELECTION_PLUGIN_STATUS_TIMEOUT errors fired by the LS60 itself, its internal source-selection plugin is struggling to switch states cleanly, which delays authentication further.

The David Sanborn “Theme from Love Is Not Enough” track is the one you’ve been testing on, it’s an MQA TIDAL FLAC (16/44 source, decoded to 24/88 by Roon’s core decoder, then rendered to 192kHz internally by the LS60). Non-MQA tracks skip the entire handshake chain, so they don’t trigger this.

Let’s see if the following steps help:

  1. Test disabling MQA on the LS60 zone in Roon: Go to Settings → Audio → KEF LS60 → Device Setup and set MQA Capabilities to "No MQA Support." Roon will then handle all decoding itself and send a clean PCM stream at 88.2kHz to the LS60, bypassing the renderer handshake entirely.
  2. Check for a KEF LS60 firmware update: The RAAT__SOURCE_SELECTION_PLUGIN_STATUS_TIMEOUT errors suggest a bug in the LS60's source-selection plugin. KEF may have addressed this in a newer firmware.

Thank you! :+1:

6

Hi Benjamin

Thank you for your detailed reply.

I have made the adjustment in the Roon Audio settings and will let you know if I have any further problems.

I have checked my KEF firmware which it is telling me is the latest version. Would it be worth me forwarding your email to KEF support for their reference or will this be sent directly from Roon?

Once again thank you for your speedy solution.

kindest regards

Julian

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Thought I’d jump in quickly to share a similar issue I’ve had since installing ls60’s (replacing 1st gen ls50w’s). It manifested itself with intermittent and brief static pops in the secondary speaker only. Everything hard wired. The primary speaker was connected to Ethernet via cat 5. Never happened with the ls50w’s. Swapped out to new cat 6a shielded cable and the issue has since subsided. Just an fyi. Cheers. Andy.

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Hey @Julian_Mullins,

Thank you for the update, and it is good to hear you have already made the adjustment in Roon Audio settings. Since your KEF firmware is already reporting as current, yes, it would be worth forwarding this to KEF support for their reference. Hearing from you, as the direct customer, will carry more weight with their team. Please let us know how it goes.