WiiM Amp Pro Firmware v5.2.726630 Update - Aug 18, 2025

Please review the WiiM Amp Pro update release notes below. If you encounter any issues, feel free to reach out to us. This firmware update is being rolled out in stages, with devices updating sequentially over the next few days.

5.2.726630 (In Progress)​

Release date:

8 / 18 / 2025

What's New:

1. Room Correction & EQ Integration: Room Correction and EQ now work together to provide an optimized listening experience. Learn More
2. Stabilized Wi-Fi Connection: Enhanced connection reliability, especially for mesh network environments.
3. Amazon Music: Bitrate information is now displayed when streaming Amazon Music Prime.
4. Sub Pro Intergartion: Improved pairing experience and overall functionality when using the Sub Pro.
5. YouTube Music: Native, seamless streaming support. (requires the upcoming app version 3.3.1).
6. Soundtrack SDK Upgrade: Under-the-hood improvements for a smoother, more consistent listening experience.

Bug Fixes:

1. Alarm Fixes:
   • Resolved an issue where weekly alarms occasionally failed to trigger.
   • Fixed a bug where only the default tone played for Pandora alarm.
2. Dolby Audio Fixes:
   • Fixed no-sound issues when playing Dolby audio in multiroom setups.
   • Corrected volume balance behavior for Dolby audio.
   • Corrected low volume when playing Dolby Digital content.
3. USB Output Fixes:
   • Resolved no-sound issues after reconnecting a USB DAC device when using Google Cast, TIDAL Connect, Spotify Connect, or Qobuz Connect.
   • Fixed audio stuttering when playing at 44.1kHz or 48kHz sample rates.
4. Playing Status: Corrected the playback status indicator when no music is playing.
5. Qobuz: Now displays the correct artist name in the app during playback.
6. Bluetooth Output: Fixed a no-audio issue after switching outputs.
7. NAS & USB Playback: Playback now correctly restarts from the beginning after the last track finishes.
8. Playback Speed: Resolved rare cases where songs played at accelerated speed.

 

[SevenAfterSix]

This new firmware update appears to have fixed a longtime issue I have had with Wi-Fi connection and the music just dropping out. All positive so far!

 

[dominikz]

@WiiM Team So the loudspeaker output inverted polarity issue is not yet fixed in this release? Issue reported in ticket #537669.

 

[slartibartfast]

@WiiM Team So the loudspeaker output inverted polarity issue is not yet fixed in this release? Issue reported in ticket #537669.

I don't suppose you know if the WiiM Amp has the same issue.

 

[dominikz]

I don't suppose you know if the WiiM Amp has the same issue.

No sorry, I don't have it so can't really say for sure.
However, looking at this set of tests by @onlyoneme the WiiM Amp seems to preserve original polarity (i.e. impulse response peak faces upwards).

 

[slartibartfast]

No sorry, I don't have it so can't really say for sure.
However, looking at this set of tests by @onlyoneme the WiiM Amp seems to preserve original polarity (i.e. impulse response peak faces upwards).

Hmm, in that case why do I need to invert my analog sub for best response?

 

[dominikz]

That is difficult to answer unambiguously without measurements. Here's some ideas off the top of my head:

• Could be the analog circuit in the subwoofer itself inverts polarity at some stage.
• Could be the WiiM Amp sub output polarity is inverted.
• Could be some acoustic phenomena around the crossover (on the sub and/or the mains) that modifies the phase sufficiently to cause a cancellation in the summed response.

In any case, it would require step-by-step troubleshooting to determine the cause.

These kind of situations really highlight why it is important to measure the response when integrating a sub - it is the only way to truly optimize the crossover!

 

[slartibartfast]

That is difficult to answer unambiguously without measurements. Here's some ideas off the top of my head:

• Could be the analog circuit in the subwoofer itself inverts polarity at some stage.
• Could be the WiiM Amp sub output polarity is inverted.
• Could be some acoustic phenomena around the crossover (on the sub and/or the mains) that modifies the phase sufficiently to cause a cancellation in the summed response.

In any case, it would require step-by-step troubleshooting to determine the cause.

These kind of situations really highlight why it is important to measure the response when integrating a sub - it is the only way to truly optimize the crossover!

Apologies is this is a daft question but which part of the impulse response would you look at to determine if the phase was correct? I have some old REW mdat files which show an initial positive movement but the next larger peak is negative.

 

[harkpabst]

Apologies is this is a daft question but which part of the impulse response would you look at to determine if the phase was correct? I have some old REW mdat files which show an initial positive movement but the next larger peak is negative.

If it's an acoustical measurements of a multi-way speaker including the WiiM Amp in the chain then this is pretty normal.

However, if you don't know if the tweeter of your speakers is wired in phase or out of phase you still cannot be sure about the absolute phase of the amp. You'll have to perform an electrical measurement of just the amp to be sure.

 

[dominikz]

Apologies is this is a daft question but which part of the impulse response would you look at to determine if the phase was correct? I have some old REW mdat files which show an initial positive movement but the next larger peak is negative.

As hinted by @harkpabst, sometimes the individual drivers in a multi-way loudspeaker aren't wired with the same polarity as a result of crossover response optimization.
As an example of this see these three step response plots for different loudspeaker models - all three have the same tweeter polarity (sharp peaks at 0us), but one has the opposite polarity for the woofer (look at the rest of the response):

So to really determine where the phase inversion happens one would need to measure at the following points:

• Electrical output measurement at the amplifier binding posts
  • Warning: The above should only be attempted if you are confident about the procedure and have adequate equipment! Amplifier loudspeaker outputs can produce high voltages and can cause damage!
• Electrical output measurement at the amplifier subwoofer output
• Acoustical nearfield output measurement of the main loudspeaker (few mm from each driver)
• Acoustical nearfield output measurement of the subwoofer (few mm from driver)
• In-room response measurement at the listening position

When looking at e.g. the step responses from above set of measurements one should be able to determine at which points exactly the polarity inversion happens.

But if we're being pragmatic, it is not really important to know where and if polarity inversion happens in individual devices.
After all, the only thing that is important is the total system response heard at the listening position and not the individual partial responses at each step of the way. Luckily the response at the listening position is relatively easy to measure.

By iteratively measuring just the response at the listening position we can fine-tune subwoofer and loudspeaker placement/polarity/delay until we achieve a magnitude response with maximum bass level and few (if any at all) nulls/dips. Once we get that, we just knock down resonances/peaks with PEQ (or RoomFit) and all is well!

Lastly, people may use several different methods in REW to find the optimal delay values; I can think of the following methods of the top of my head:

1. Some will gradually change the delay until the smoothest in-room magnitude frequency response is achieved
2. Some will use the built-in IR delay estimation (I believe @EddNog used this method recently)
3. Some will use the phase plot to visually match the subwoofer and loudspeaker phase slopes around the crossover
4. Some will use the excess phase group delay plot to directly estimate the delay differences at the crossover

Note that all except the first method require using a fixed timing reference in REW.

 

[slartibartfast]

As hinted by @harkpabst, sometimes the individual drivers in a multi-way loudspeaker aren't wired with the same polarity as a result of crossover response optimization.
As an example of this see these three step response plots for different loudspeaker models - all three have the same tweeter polarity (sharp peaks at 0us), but one has the opposite polarity for the woofer (look at the rest of the response):

So to really determine where the phase inversion happens one would need to measure at the following points:

• Electrical output measurement at the amplifier binding posts
  • Warning: The above should only be attempted if you are confident about the procedure and have adequate equipment! Amplifier loudspeaker outputs can produce high voltages and can cause damage!
• Electrical output measurement at the amplifier subwoofer output
• Acoustical nearfield output measurement of the main loudspeaker (few mm from each driver)
• Acoustical nearfield output measurement of the subwoofer (few mm from driver)
• In-room response measurement at the listening position

When looking at e.g. the step responses from above set of measurements one should be able to determine at which points exactly the polarity inversion happens.

But if we're being pragmatic, it is not really important to know where and if polarity inversion happens in individual devices.
After all, the only thing that is important is the total system response heard at the listening position and not the individual partial responses at each step of the way. Luckily the response at the listening position is relatively easy to measure.

By iteratively measuring just the response at the listening position we can fine-tune subwoofer and loudspeaker placement/polarity/delay until we achieve a magnitude response with maximum bass level and few (if any at all) nulls/dips. Once we get that, we just knock down resonances/peaks with PEQ (or RoomFit) and all is well!

Lastly, people may use several different methods in REW to find the optimal delay values; I can think of the following methods of the top of my head:

1. Some will gradually change the delay until the smoothest in-room magnitude frequency response is achieved
2. Some will use the built-in IR delay estimation (I believe @EddNog used this method recently)
3. Some will use the phase plot to visually match the subwoofer and loudspeaker phase slopes around the crossover
4. Some will use the excess phase group delay plot to directly estimate the delay differences at the crossover

Note that all except the first method require using a fixed timing reference in REW.

My impulse response looks very different to that. Any ideas?


OK I found the step response in overlays. Closer but still noticeably different.

 

[dominikz]

My impulse response looks very different to that. Any ideas?
View attachment 25621

Yes, two main reasons:

1. I showed step responses in my previous post and yours appears to be an impulse response.
2. The step responses I showed are quasi-anechoic (i.e. just the loudspeaker response without any reflections), while your impulse response seems to be in-room (i.e. containing reflections).

If you're interested in making your own quasi-anechoic measurements this step by step guide from ASR might be useful!

 

[slartibartfast]

Yes, two main reasons:

1. I showed step responses in my previous post and yours appears to be an impulse response.
2. The step responses I showed are quasi-anechoic (i.e. just the loudspeaker response without any reflections), while your impulse response seems to be in-room (i.e. containing reflections).

If you're interested in making your own quasi-anechoic measurements this step by step guide from ASR might be useful!

Yup I realised that after I posted. I added a step response to my post only measured at the listening position though.

 

[dominikz]

Yup I realised that after I posted. I added a step response to my post only measured at the listening position though.

The remaining differences are caused by room reflections and any differences in loudspeaker response - note that step response and frequency response (magnitude+phase) are actually just two visual representations of the same data.

This means that loudspeakers with different (magnitude+phase) frequency responses will also have different step responses.
You can see this even in my example which shows (quasi-anechoic) step responses of 3 different loudspeakers. Even though all three have reasonably flat magnitude frequency responses, the individual differences in extension, magnitude response shape and phase responses still results in different looking step responses.

 

[slartibartfast]

The remaining differences are caused by room reflections and any differences in loudspeaker response - note that step response and frequency response (magnitude+phase) are actually just two visual representations of the same data.

This means that loudspeakers with different (magnitude+phase) frequency responses will also have different step responses.
You can see this even in my example which shows (quasi-anechoic) step responses of 3 different loudspeakers. Even though all three have reasonably flat magnitude frequency responses, the individual differences in extension, magnitude response shape and phase responses still results in different looking step responses.

My step response seems to imply that the Amp output isn't inverted (I think) so it still seems strange that I need to invert the subwoofer output.

 

[dominikz]

My step response seems to imply that the Amp output isn't inverted (I think) so it still seems strange that I need to invert the subwoofer output.

I'm afraid that from this single step response we can't determine what exactly is happening.

 

[flxy]

Damn, this update has ruined a night for me.

A total disaster. It completely broke Bluetooth connectivity with my Raspberry Pi 4 running LibreELEC. The Pi suddenly cannot connect, and after wasting an hour troubleshooting, I realized it was the update silently installed overnight and caused the issue.

Ruined my evening with friends, as I could not stream a movie to my WiiM-powered speakers. The lack of a 3.5" audio-in jack is already a major limitation, and now silent, unstoppable updates are making this device unreliable.

When everything is working fine - I don't need no damn updates.

Please release a fix for this firmware issue and give users control over the updates!

---

 

[Wiimer]

Damn, this update has ruined a night for me.

A total disaster. It completely broke Bluetooth connectivity with my Raspberry Pi 4 running LibreELEC. The Pi suddenly cannot connect, and after wasting an hour troubleshooting, I realized it was the update silently installed overnight and caused the issue.

Ruined my evening with friends, as I could not stream a movie to my WiiM-powered speakers. The lack of a 3.5" audio-in jack is already a major limitation, and now silent, unstoppable updates are making this device unreliable.

When everything is working fine - I don't need no damn updates.

Please release a fix for this firmware issue and give users control over the updates!

---

Have you submitted a ticket to WiiM support? Submitting a ticket via the feedback section of the WiiM app will send a log of the device.

Also, unplugging the device's power cable and rebooting it may resolve the issue.

 

[flxy]

Have you submitted a ticket to WiiM support? Submitting a ticket via the feedback section of the WiiM app will send a log of the device.

Also, unplugging the device's power cable and rebooting it may resolve the issue.

yes, of course I powered it down for a while and tried again and it won't connect - RPi is throwing bluetooth errors (which never happened before the update got silently installed the night before).

It is very arrogant by WiiM developers to force feed users with the automatic updates, which can not be disabled.
There is an old saying among computer enthusiasts: if everything is working as expected, do not touch it. Updates should not be applied simply for the sake of updates or to add features that are not needed.

The reasoning that many users fail to install updates and then complain about bugs that may already be fixed is flawed. A better approach would be to educate users to install updates when they are dissatisfied with the device. Forcing botched updates on users who are satisfied with the current performance is unacceptable.

 

[harkpabst]

yes, of course I powered it down for a while and tried again and it won't connect - RPi is throwing bluetooth errors (which never happened before the update got silently installed the night before).

It is very arrogant by WiiM developers to force feed users with the automatic updates, which can not be disabled.
There is an old saying among computer enthusiasts: if everything is working as expected, do not touch it. Updates should not be applied simply for the sake of updates or to add features that are not needed.

The reasoning that many users fail to install updates and then complain about bugs that may already be fixed is flawed. A better approach would be to educate users to install updates when they are dissatisfied with the device. Forcing botched updates on users who are satisfied with the current performance is unacceptable.

I just connected my WiiM Amp Ultra via Bluetooth to my WiiM Amp Pro successfully. However, I noticed that my firmware version reads 5.2.726631, not 5.2.726630. The build date is identical, 20250818.

Edit: Sorry, wrong way around. Let me try again.

Edit 2: My WiiM Amp Pro (firmware 5.2.726630) couldn't detect my WiiM Amp Ultra. I didn't find a way to keep the Amp Ultra from trying to connect to my computer, though (which had Bluetooth disabled).