WiiM Pro no longer bit perfect?

[hopkins]

I got a message displayed today on the WiiM app saying my WiiM Pro had been updated with some changes to the SPDIF input (something about sample rate tracking? I forget). I re-checked for "bit-perfectness" (my DAC has an integrated bit-perfect test - ECDesigns' PowerDAC-SX) and the WiiM Pro is NO LONGER bit-perfect at 44, 48 and 88khz! It is only bit perfect at 96khz.

I have obviously turned off EQ and have it set to fixed volume output.

Test was performed with Squeezelite. It was bit-perfect before, no other changes have been made to my setup.

Firmware version is 4.8.539439

 

[onlyoneme]

It still passes RME bit-perfect test.

 

[hopkins]

It still passes RME bit-perfect test.

Do you have the same firmware version? Have you checked all sample rates? What streaming protocol are you using?

 

[onlyoneme]

The same FW on both the Pro and the Pro Plus, with LMS and DLNA.

 

[onlyoneme]

And regardless of the sample rate.

 

[hopkins]

Thanks. I just figured out what was happening.

If the tracks are played individually, then the bit-perfect test is ok. If all the tracks (44, 48, 88 and 96) are placed in the LMS queue and the queue is played only the 96 khz track is bit perfect.

I checked also placing in the queue my two 44khz test files - bit-perfect. Placing the 44khz file AND any other sample rate file immediately after, and the first 44khz file fails but the second is ok.

This was not the case before, but so be it. An album always has the same sample rate so not a problem, for me at least. If you add to your playback queue albums with multiple sample rates, some form of resampling may be going on...

 

[Brantome]

Thanks. I just figured out what was happening.

If the tracks are played individually, then the bit-perfect test is ok. If all the tracks (44, 48, 88 and 96) are placed in the LMS queue and the queue is played only the 96 khz track is bit perfect.

This was not the case before, but so be it. An album always has the same sample rate so not a problem.

I’d still bug report it if you feel it’s a change in behaviour. @d6jg, any thoughts?

 

[canard]

⁰

Thanks. I just figured out what was happening.

If the tracks are played individually, then the bit-perfect test is ok. If all the tracks (44, 48, 88 and 96) are placed in the LMS queue and the queue is played only the 96 khz track is bit perfect.

I checked also placing in the queue my two 44khz test files - bit-perfect. Placing the 44khz file AND any other sample rate file immediately after, and the first 44khz file fails but the second is ok.

This was not the case before, but so be it. An album always has the same sample rate so not a problem, for me at least. If you add to your playback queue albums with multiple sample rates, some form of resampling may be going on...

It remains an interesting observation...especially if it wasn't the case before this firmware

 

[hopkins]

It was not the case before, but I did not perform the test with each firmware update - only this last one mentioning SPDIF input changes prompted me to perform the test again.

 

[onlyoneme]

If you add to your playback queue albums with multiple sample rates, some form of resampling may be going on...

I haven't noticed such a behavior. I made a queue with 4 test signals at different sample rates and every test signal passes the test. My DAC also reacts to sample rate changes and shows the current one correctly.

 

[hopkins]

I feel that since WiiM advertises bit-perfectness, then they should test this with every firmware update ..

 

[hopkins]

I haven't noticed such a behavior. I made a queue with 4 test signals at different sample rates and every test signal passes the test. My DAC also reacts to sample rate changes and shows the current one correctly.

That's odd. Maybe WiiM can give us some feedback on their test protocol.

 

[onlyoneme]

What is the sample rate which your DAC reports when playing a queue?

 

[hopkins]

What is the sample rate which your DAC reports when playing a queue?

My DAC does not display the sample rates. It just displays an indicator (P) when the test succeeds.

 

[hopkins]

What is the sample rate which your DAC reports when playing a queue?

How many seconds are your test tracks?

The test tracks provided by my DAC's manufacturer are between 3 and 5 seconds long. The check is performed on the whole track.

 

[onlyoneme]

My DAC does not display the sample rates. It just displays an indicator (P) when the test succeeds.

I see. Did you also try with interfaces other than LMS?

 

[onlyoneme]

How many seconds are your test tracks?

The test tracks provided by my DAC's manufacturer are between 3 and 5 seconds long. The check is performed on the whole track.

4 seconds each of them. Passing the test guarantees that no constant stream manipulation, like digital volume change or resampling, is applied.
A long file capture and compare with the source should be made to make sure that nothing changes in the time domain, but I do not have time atm for such test.

 

[Brantome]

What is the sample rate which your DAC reports when playing a queue?

Mine still changes track by track when playing from LMS - same resolution in LMS shows in WiiM app and on my DAC/amp, and all keep in step track by track.

 

[hopkins]

I see. Did you also try with interfaces other than LMS?

No. Maybe WiiM can give us some feedback on all this.

 

[Brantome]

No. Maybe WiiM can give us some feedback on all this.

This is primarily a user forum and WiiM only pop in occasionally. If you want feedback from them, best to raise a ticket as I suggested above

Doing that means they can inspect your device logs for evidence of the issue.