Can any samsung s21 users try this and see if they get 990kbps? General
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Junior Member 26 posts Simon Spero Junior Member 26 posts
Simon Spero
I've found what might be a clue to the samsung ldac bit rate problem  but I'm not sure if it's idiosyncratic.

With LDAC ABR (best effort) selected, which is the default, 
I've found that I usually end up with a low bitrate being used (often below 660). However, if I toggle LDAC off and on I can usually end up at a bitrate of 990kbps. It seems to take a variable number of times before the behavior is engaged. 

I have a few screen recordings with a split screen showing the qudelix app input state screen ( to see bit rate) , and the system bt device control panel (to toggle ldac on/off). I can upload them if what I've written is confusing. 

that stays stable for 10m before the rate has to back off). 
The behavior doesn't seem to be related to background interference, as the higher rate doesn't degrade if I go out.

I'm pretty sure this isn't a Qudelix specific issue due to the well known LDAC issues with the s20/21, which don't occur with older sources (e.g. Tab S3) and do occur from same source to  other sinks (e.g. Sony WH1000XM4).

Can anyone else trigger this behavior?  
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Qudelix Support qudelix Qudelix 2,093 posts
Qudelix Support qudelix

What do you mean by 'toggle LDAC off and on'?

Qudelix-5K is the only and the first LDAC receiver which displays the real-time active LDAC bitrate.
Users had not been able to check the bitrate before Qudelix-5K.

As we checked, some(or most) Samsung Android devices don't support LDAC 990kbps adequately. 

If you 

  • use WiFi 5GHz instead of 2.4GHz
  • turn your phone screen off

, then you can get the LDAC 990kbps.

You can't check the bitrate using the mobile app because you need to turn the screen off. You will need to check the bitrate using the Qudelix PC Chrome app.
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Simon Spero Junior Member 26 posts
Simon Spero
This is with the screen on, which is what surprised me the first time I ended up in this state.

It makes it seem much more likely that the issue is software not hardware. 

See the attached screen recording  at ~0:28 for an example. 
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Qudelix Support qudelix Qudelix 2,093 posts
Qudelix Support qudelix
If you turn the LDAC off, the audio goes with aptX as displayed in the app.
Turning on/off the LDAC has nothing to do with the LDAC bitrate.

It's an SS Galaxy Android HW issue.
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Simon Spero Junior Member 26 posts
Simon Spero
Did you look at the video? 
After 0:28 it locks on at 990kbps.

Not seen in the video, but with fixed 990kbps is engaged from dev options (with  bit depth changed to make change apply - another samsung ldac bug) it goes stutter free in the same situation as ABr getting to 990kbps. 
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superpower77 Junior Member 13 posts
superpower77
I confirm after switching from 2.4Ghz to 5Ghz on my Samsung Galaxy A52 G5 and S21+ phones, LDAC bit-rate went from 330Kbps to 990Kbps. Just Tested with Tidal HiFi plus and Amazon unlimited HD music streaming services.
Screenshot_20220308-171515_Qudelix.jpg 
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Simon Spero Junior Member 26 posts
Simon Spero
Going the other way, I've  found that switching to 2.4GHz wifi seems to force 330kbps, and when I had 990kbps prior to being on 2.4GHz wifi, switching to (not that) ramped back up. (At the time I was in a supermarket pharmacy waiting for my booster, so I didn't spend much time investigating. Here's to a future where both bugs are finally fixed 🙂 
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