My WiiM Pro Plus (+) tests

[canard]

same as mine. Time to reinstall the app probably.


But no luck.

Edit: wrong security settings in LMS. Everything is fine.

surprising that you did not receive the non-beta version, "modified" in view of the efforts you produce for wiim and to be able to observe the differences or not between beta and finalized..
(you offer the most complete and dense study...)

 

[onlyoneme]

Short comparison of frequency responses between different filters of the Pro Plus:

 

[onlyoneme]

Both fast linear and fast min phase filters have similar responses. It's the same also for both slow filters. NOS filter has very bad attenuation for high frequencies, as expected.

 

[onlyoneme]

Impulse responses, starting from fast linear, then fast min phase, slow linear, slow min phase, NOS and low dispersion:

 

[canard]

thank you...
classic..
;-)
but:

ap32?
smpte? ccif?

--- thd-thd+n vs frequency?



somes sensibles differences with differents filters?
;-)

 

[onlyoneme]

thank you...
classic..
;-)
but:

ap32?
smpte? ccif?

--- thd-thd+n vs frequency?



somes sensibles differences with differents filters?
;-)

Soon

For now I can say that there is no difference in THD vs frequency sweeps for all slow and fast filters.

 

[canard]

always the same comportement

Soon

For now I can say that there is no difference in THD vs frequency sweeps for all slow and fast filters.

(Are we talking about your “plus” beta? not the “plus" commercialized?)

 

[onlyoneme]

Everything above is about my old pre-prod Pro Plus, it's the only sample I got.

No difference in distortion levels between filters at low frequencies. Changing the filter will not improve the performance in this case.
And a different story with high frequencies as shown in CCIF test due to different attenuation levels and strong aliases for the NOS filter:

 

[steadyshot]

Fast seems the best choice in the above graph. Is this the default ? Although at 1k slow behaves better

 

[canard]

Everything above is about my old pre-prod Pro Plus, it's the only sample I got.

No difference in distortion levels between filters at low frequencies. Changing the filter will not improve the performance in this case.
And a different story with high frequencies as shown in CCIF test due to different attenuations levels and strong aliases for the NOS filter:

View attachment 2481

at high frequencies it is logical...but let's hope that there is really a difference under 1k in thd...etc with the "modified" version..
it has never been explained in what way has been modified...in my opinion it's very clumsy...
(no thd vs frequency, the more explicite...?? ;-) )

 

[Balthazar B]

If this link was posted here earlier, I missed it, but here's a nice paper discussing the effects of digital filters specifically with the AKM 4493-series DACs, like the one used in the Pro Plus:

DAC digital filters part 2 – deeper dive into AK4490 and AK4493 filters - nihtila.com

This post delves into digital filters in AK4490 and AK4493 DACs used in W-DAC boards and provides extensive measurement results of the filters in time and frequency domain. This is not only relevant to these specific DAC chips and filters but general information on DAC digital filters from audio...

nihtila.com

 

[Nanook]

Part 1 - analog section

The one and only graph for today - a classic sine 1kHz. Compared to the Mini, both left channel, 2vrms output. Measured in REW.

When trying to measure the ADC performance of my new WiiM Pro Plus I was initially not able to get the line input routed to whatever output. In the end I managed to get it working - guess what made the trick?
Initially I connected the generator signal only to L or R because using REW I wanted to measure both channels sequentially anyways. Once I connected the signal to L and R in parallel it worked immediately. It wasn't about feeding a signal into both inputs, it was rather to have a RCA plug inserted in both input jacks, otherwise the signal does not get routed. There seems to be some contact in the RCA jacks that senses if connectors are plugged.
From a practical point of view this is not a problem at all and actually makes sense - you would use both channels anyways. I just want to mention this in case someone stumbles across this peculiarity as well.

I can confirm that the ADC starts to clip at ca. 2.1Vrms - this is indeed a bit tight.
@WiiM Team: -> Did I miss an indication of an overload condition, or is this important feature just not implemented?
An indication of the peak level in the App would be nice - if this is technically to challenging, I'd be happy if the front LED would light up red when the line input clips.
Would probably be a nice feature also for the DAC part - using the EQ this could happen - or does the App enforce enough headroom automatically when you boost frequency regions?

 

[Burnside]

Would probably be a nice feature also for the DAC part - using the EQ this could happen - or does the App enforce enough headroom automatically when you boost frequency regions?

See
Post in thread 'Does using EQ degrade sound quality in Wiim Pro?'
https://forum.wiimhome.com/threads/does-using-eq-degrade-sound-quality-in-wiim-pro.6534/post-115229