Introducing WiiM Sub Pro: Experience Bass Like Never Before

Steve Woodhouse · Jul 27, 2025

dominikz said:
Hm, how could RC be run on the Sub Pro in isolation before pairing it with the main WiiM device (e.g. Ultra)?
What would be used as reference level to set the target curve if we didn't measure the full spectrum (sub+mains), and what about the crossover region?

As I see it, it only makes sense to run room correction after the Sub Pro is paired with a main device and crossover is optimized. It should still be possible to use 10 PEQs on the sub for the area below the crossover, and 2x10 PEQs (10 per channel) on the main WiiM device for the area above the crossover.

Can you explain in a bit more detail how this all works?

Is this any different to how other subs with an app on your phone work?

WiiM Team · Jul 28, 2025

dominikz said:
Hm, how could RC be run on the Sub Pro in isolation before pairing it with the main WiiM device (e.g. Ultra)?
What would be used as reference level to set the target curve if we didn't measure the full spectrum (sub+mains), and what about the crossover region?

As I see it, it only makes sense to run room correction after the Sub Pro is paired with a main device and crossover is optimized. It should still be possible to use 10 PEQs on the sub for the area below the crossover, and 2x10 PEQs (10 per channel) on the main WiiM device for the area above the crossover.

Can you explain in a bit more detail how this all works?

Hi @dominikz ,

Yes, you can run Room Correction (RC) on the Sub Pro individually without pairing. With the latest Sub Pro and app version, this is supported. In this setup, the Sub Pro provides 10 PEQs, while the main device offers 2×10 PEQs.

EddNog · Jul 28, 2025

WiiM Team said:
Hi @dominikz ,

Yes, you can run Room Correction (RC) on the Sub Pro individually without pairing. With the latest Sub Pro and app version, this is supported. In this setup, the Sub Pro provides 10 PEQs, while the main device offers 2×10 PEQs.

Heck yeah now we’re cooking with fire!

-Ed

slartibartfast · Jul 28, 2025

WiiM Team said:
Hi @dominikz ,

Yes, you can run Room Correction (RC) on the Sub Pro individually without pairing. With the latest Sub Pro and app version, this is supported. In this setup, the Sub Pro provides 10 PEQs, while the main device offers 2×10 PEQs.

So how does it determine the target curve level without measuring the whole system volume?

Steve Woodhouse · Jul 29, 2025

slartibartfast said:
So how does it determine the target curve level without measuring the whole system volume?

The obvious way to tackle it would be to EQ sub, EQ mains, than change the sub level as part of the second calibration, or immediately at the end.

dominikz · Jul 29, 2025

Steve Woodhouse said:
The obvious way to tackle it would be to EQ sub, EQ mains, than change the sub level as part of the second calibration, or immediately at the end.

Personally I believe doing it this way would make the process more complicated, may result in sub-optimal correction (especially below and around the crossover), and unnecessarily wastes PEQ bands.

Here's why I think so:

If we EQ the sub in isolation that means the crossover parameters are not yet defined. That implies that the 10-band PEQ of the Sub Pro will correct the whole 25-200Hz range the subwoofer plays.
The question of the appropriate target curve level remains, as without having the rest of the spectrum as reference setting the curve level is almost a random choice.
- E.g. it might happen that RoomFit selects a high relative level for the Sub Pro target curve and tries to boost with PEQs to match the target (which might not work for acoustic cancellations), while later you might find you need to reduce the overall subwoofer gain to match the mains.
Once we pair the (RoomFitted) Sub Pro with the main device and set the crossover at e.g. 80Hz, any Sub Pro PEQ filters utilized above 80Hz no longer have any purpose - they would be effectively wasted.
In the crossover region (around 80Hz in this example) filters from both the Sub Pro and the main WiiM device might be needed to smooth out the response. However, since Sub Pro filters were already set prior to pairing, we now can only use the main WiiM device PEQ filters to try and resolve this, again effectively wasting some EQ filter bands.

It seems to me a much easier and more efficient method would be to use the following approach instead:

Pair the Sub Pro with the main WiiM device.
Add any time delay to the main WiiM device to align the sub and the mains.
Optimize the subwoofer crossover parameters (level, phase and frequency).
Run RoomFit, where the Sub Pro applies its own 10-band PEQ bands below the crossover, and the main WiiM device applies its 2x10 PEQ bands above the crossover. The target curve is easily fit to the measured response, since it contains the full spectrum.

Of course WiiM is free to develop their features as they see Fit (pun intended

), but the design choices (as communicated so far) seem strange to me.

Just my 2 cents!

EddNog · Jul 29, 2025

dominikz said:
...It seems to me a much easier and more efficient method would be to use the following approach instead:

Pair the Sub Pro with the main WiiM device.

Add any time delay to the main WiiM device to align the sub and the mains.

Optimize the subwoofer crossover parameters (level, phase and frequency).

Run RoomFit, where the Sub Pro applies its own 10-band PEQ bands below the crossover, and the main WiiM device applies its 2x10 PEQ bands above the crossover. The target curve is easily fit to the measured response, since it contains the full spectrum.

...

This is the approach that I've had the most success with in the past (the only difference being for the bolded part where I was using a DSPeaker Anti-Mode unit instead since my subwoofers didn't have built-in RC). The only caveat is you need to re-check the crossover response once everything is done because the correction/PEQ filters have an effect on time/phase and sometimes it can adversely affect crossover behavior which will then need minor adjustment (typically a small adjustment to either the delay and/or phase if your system allows fine phase adjustment like SVS subs which can do 1-degree phase increments).

-Ed

Wiimer · Jul 29, 2025

As always, here are my (useless) predictions

1) If the Sub pro and the WiiM device are connected wirelessly.

Run RC on the Sub pro after pairing the Sub pro and WiiM. Adjust the crossover, volume and phase and manually adjust them while running RC again. Then use the RC on the WiiM to correct the frequencies above the crossover.
(Parts of this procedure could be automated).

2) If the Sub pro and a third party device are connected by cable.

If the device does not have the ability to adjust the sub, adjust the low pass, phase and volume on the Sub pro and run RC.

Wiimer · Jul 29, 2025

And another scenario for (1) is to do all corrections on the main WiiM device side. However, currently it is not possible to reflect the RC results of the lead device on the follow device.

It would be interesting if the team made this possible

EddNog · Jul 29, 2025

Wiimer said:
And another scenario for (1) is to do all corrections on the main WiiM device side. However, currently it is not possible to reflect the RC results of the lead device on the follow device.

It would be interesting if the team made this possible

Connect your smart phone to the WiiM using Bluetooth Input, then run (free!) HouseCurve app on smartphone and perform frequency response sweeps to see the total system response.

-Ed

Wiimer · Jul 29, 2025

EddNog said:
Connect your smart phone to the WiiM using Bluetooth Input, then run (free!) HouseCurve app on smartphone and perform frequency response sweeps to see the total system response.

-Ed

When will RoomFit be used?

jiaxin.li (WiiM) · Jul 29, 2025

dominikz said:
Personally I believe doing it this way would make the process more complicated, may result in sub-optimal correction (especially below and around the crossover), and unnecessarily wastes PEQ bands.

Here's why I think so:

If we EQ the sub in isolation that means the crossover parameters are not yet defined. That implies that the 10-band PEQ of the Sub Pro will correct the whole 25-200Hz range the subwoofer plays.

The question of the appropriate target curve level remains, as without having the rest of the spectrum as reference setting the curve level is almost a random choice.

E.g. it might happen that RoomFit selects a high relative level for the Sub Pro target curve and tries to boost with PEQs to match the target (which might not work for acoustic cancellations), while later you might find you need to reduce the overall subwoofer gain to match the mains.

Once we pair the (RoomFitted) Sub Pro with the main device and set the crossover at e.g. 80Hz, any Sub Pro PEQ filters utilized above 80Hz no longer have any purpose - they would be effectively wasted.

In the crossover region (around 80Hz in this example) filters from both the Sub Pro and the main WiiM device might be needed to smooth out the response. However, since Sub Pro filters were already set prior to pairing, we now can only use the main WiiM device PEQ filters to try and resolve this, again effectively wasting some EQ filter bands.

It seems to me a much easier and more efficient method would be to use the following approach instead:

Pair the Sub Pro with the main WiiM device.

Add any time delay to the main WiiM device to align the sub and the mains.

Optimize the subwoofer crossover parameters (level, phase and frequency).

Run RoomFit, where the Sub Pro applies its own 10-band PEQ bands below the crossover, and the main WiiM device applies its 2x10 PEQ bands above the crossover. The target curve is easily fit to the measured response, since it contains the full spectrum.

Of course WiiM is free to develop their features as they see Fit (pun intended ), but the design choices (as communicated so far) seem strange to me.

Just my 2 cents!

Hello, thank you very much for sharing such a detailed and insightful perspective!

The approach you suggested—pairing first, then performing time alignment, level matching, and crossover optimization before running RoomFit—makes a lot of sense. It’s definitely a more efficient way to utilize PEQ resources, especially for achieving smoother integration in the crossover region. We do plan to introduce time calibration, level adjustment, and crossover optimization features in future updates to allow for more precise system tuning.

Currently, the Sub Pro’s EQ range is set from 30Hz to 110Hz, while the WiiM device’s EQ is applied above the crossover point. So at this stage, RoomFit still covers the key frequency regions reasonably well. That said, we’re continuously working to improve the processing logic to make the calibration workflow even more intelligent and coordinated.

We really appreciate your feedback, and we welcome any further suggestions you may have!

Wiimer · Jul 29, 2025

dominikz said:
Pair the Sub Pro with the main WiiM device.

Add any time delay to the main WiiM device to align the sub and the mains.

Optimize the subwoofer crossover parameters (level, phase and frequency).

Run RoomFit, where the Sub Pro applies its own 10-band PEQ bands below the crossover, and the main WiiM device applies its 2x10 PEQ bands above the crossover. The target curve is easily fit to the measured response, since it contains the full spectrum.

Excellent suggestions.

It would be great if we could run RoomFit after 1, and automate 2 and 3.
(Of course, it can be tweaked manually.)

slartibartfast · Jul 29, 2025

jiaxin.li (WiiM) said:
Hello, thank you very much for sharing such a detailed and insightful perspective!

The approach you suggested—pairing first, then performing time alignment, level matching, and crossover optimization before running RoomFit—makes a lot of sense. It’s definitely a more efficient way to utilize PEQ resources, especially for achieving smoother integration in the crossover region. We do plan to introduce time calibration, level adjustment, and crossover optimization features in future updates to allow for more precise system tuning.

Currently, the Sub Pro’s EQ range is set from 30Hz to 110Hz, while the WiiM device’s EQ is applied above the crossover point. So at this stage, RoomFit still covers the key frequency regions reasonably well. That said, we’re continuously working to improve the processing logic to make the calibration workflow even more intelligent and coordinated.

We really appreciate your feedback, and we welcome any further suggestions you may have!

Will time alignment be performed using a microphone at the listening position? The current sub/speaker synchronisation uses the microphone built into the device and is suboptimal for that reason.

dominikz · Jul 30, 2025

jiaxin.li (WiiM) said:
Hello, thank you very much for sharing such a detailed and insightful perspective!

The approach you suggested—pairing first, then performing time alignment, level matching, and crossover optimization before running RoomFit—makes a lot of sense. It’s definitely a more efficient way to utilize PEQ resources, especially for achieving smoother integration in the crossover region. We do plan to introduce time calibration, level adjustment, and crossover optimization features in future updates to allow for more precise system tuning.

Currently, the Sub Pro’s EQ range is set from 30Hz to 110Hz, while the WiiM device’s EQ is applied above the crossover point. So at this stage, RoomFit still covers the key frequency regions reasonably well. That said, we’re continuously working to improve the processing logic to make the calibration workflow even more intelligent and coordinated.

We really appreciate your feedback, and we welcome any further suggestions you may have!

Thanks for the thoughtful response!

It is really great to hear you are taking such feedback into consideration, and that you're continuously working on improving the RC functionality!

As it stands RoomFit is already working quite well, but IMHO has potential to become a real market-differentiating feature.

IMHO room correction implementation should ideally cater to two very different customer pools at the same time:

Advanced users who want more control of the process, and therefore more manual tuning options.
- This would require adding more functionality like integration with REW (including import and export of EQ filters and export of measured responses), manually triggered response validation, manual EQ pre-gain control, automated EQ headroom calculation, custom target curve import, manual tuning of target curve level, loudspeaker response correction (manual or based on presets from spinorama.org), etc.
Non-technical users who normally want their devices to be plug-and-play and sound good - meaning more automation and detailed setup guidance.
- This would require detailed visual guides for the whole tuning process in the app, including how to make the appropriate connections and how to best place loudspeakers/subwoofers to avoid (or minimize) common acoustical interference issues like SBIR while preserving headroom (in various typical system layouts).
- It would also require a totally automated tuning process (including optimizing the subwoofer crossover settings), and improvements to default parameter selection for RoomFit (to minimize any chance of making the sound worse rather than better).
- An app UI and online FAQ overhaul would be required as well, especially to improve some clumsy parameter names, and any unclear, incorrect and/or obsolete explanations.
- Improvements to the measurement process would be needed, especially handling of microphone (in)accuracies.
  - I see that there is an intention to introduce calibration files for common mobile phone microphones, which is IMHO a very good idea and perhaps even crucial - though I understand it will be quite difficult to maintain this long-term with the rate new mobile devices come to market. A complication is that some mobile devices seem to process and modify the responses of even externally connected microphones.
  - I'd also suggest to consider using the WiiM Voice Remote microphone for calibrations (since it is already included with some devices) and to perhaps also consider shipping new devices with a dedicated pre-calibrated microphone for system tuning. The intention should IMHO be to decrease reliance on external/3rd-party devices for system tuning and thereby mitigate unknown sources of error.
- Without such improvements there could be a significant number of users who get worse sound with RoomFit than they did without it - which should really never happen!
- Consider adding easy and intuitive overall tonality adjustment (post-RoomFit) with a single tone 'tilt' control to allow on-the-fly adjustment to taste or to adjust playback to current content.

In the end whatever you do it will not be possible to satisfy everyone, but perhaps some of these suggestions might still be helpful!

Burnside · Jul 30, 2025

Re “shipping new devices with a dedicated pre-calibrated microphone for system tuning”, I’m sure everyone who ever bought a Yamaha AVR remembers the little YPAO mic that was in the box…

jiaxin.li (WiiM) · Jul 30, 2025

dominikz said:
Thanks for the thoughtful response!

It is really great to hear you are taking such feedback into consideration, and that you're continuously working on improving the RC functionality!

As it stands RoomFit is already working quite well, but IMHO has potential to become a real market-differentiating feature.

IMHO room correction implementation should ideally cater to two very different customer pools at the same time:

Advanced users who want more control of the process, and therefore more manual tuning options.

This would require adding more functionality like integration with REW (including import and export of EQ filters and export of measured responses), manually triggered response validation, manual EQ pre-gain control, automated EQ headroom calculation, custom target curve import, manual tuning of target curve level, loudspeaker response correction (manual or based on presets from spinorama.org), etc.

Non-technical users who normally want their devices to be plug-and-play and sound good - meaning more automation and detailed setup guidance.

This would require detailed visual guides for the whole tuning process in the app, including how to make the appropriate connections and how to best place loudspeakers/subwoofers to avoid (or minimize) common acoustical interference issues like SBIR while preserving headroom (in various typical system layouts).

It would also require a totally automated tuning process (including optimizing the subwoofer crossover settings), and improvements to default parameter selection for RoomFit (to minimize any chance of making the sound worse rather than better).

An app UI and online FAQ overhaul would be required as well, especially to improve some clumsy parameter names, and any unclear, incorrect and/or obsolete explanations.

Improvements to the measurement process would be needed, especially handling of microphone (in)accuracies.

I see that there is an intention to introduce calibration files for common mobile phone microphones, which is IMHO a very good idea and perhaps even crucial - though I understand it will be quite difficult to maintain this long-term with the rate new mobile devices come to market. A complication is that some mobile devices seem to process and modify the responses of even externally connected microphones.

I'd also suggest to consider using the WiiM Voice Remote microphone for calibrations (since it is already included with some devices) and to perhaps also consider shipping new devices with a dedicated pre-calibrated microphone for system tuning. The intention should IMHO be to decrease reliance on external/3rd-party devices for system tuning and thereby mitigate unknown sources of error.

Without such improvements there could be a significant number of users who get worse sound with RoomFit than they did without it - which should really never happen!

Consider adding easy and intuitive overall tonality adjustment (post-RoomFit) with a single tone 'tilt' control to allow on-the-fly adjustment to taste or to adjust playback to current content.

In the end whatever you do it will not be possible to satisfy everyone, but perhaps some of these suggestions might still be helpful!

Hello, thank you very much for your detailed suggestions!
We fully agree with your point about meeting the needs of both advanced users and non-technical users:
Advanced users want more manual control, such as EQ import/export, custom target curves, and measurement validation;
Non-technical users prefer a simple one-click calibration that automatically delivers a pleasing sound without needing to understand technical details.
We are indeed considering developing RoomFit along this dual-mode approach to cater both to enthusiasts who enjoy fine-tuning and to everyday users who value ease of use.
Your valuable feedback has been carefully noted and will be taken into account in future improvements. We look forward to hearing more of your thoughts!

slartibartfast · Jul 30, 2025

jiaxin.li (WiiM) said:
Hello, thank you very much for your detailed suggestions!
We fully agree with your point about meeting the needs of both advanced users and non-technical users:
Advanced users want more manual control, such as EQ import/export, custom target curves, and measurement validation;
Non-technical users prefer a simple one-click calibration that automatically delivers a pleasing sound without needing to understand technical details.
We are indeed considering developing RoomFit along this dual-mode approach to cater both to enthusiasts who enjoy fine-tuning and to everyday users who value ease of use.
Your valuable feedback has been carefully noted and will be taken into account in future improvements. We look forward to hearing more of your thoughts!

It appears you might have missed my question in post #174

S

Post in thread 'Introducing WiiM Sub Pro: Experience Bass Like Never Before'

Jul 29, 2025

jiaxin.li (WiiM) said:
Hello, thank you very much for sharing such a detailed and insightful perspective!

The approach you suggested—pairing first, then performing time alignment, level matching, and crossover optimization before running RoomFit—makes a lot of sense. It’s definitely a more efficient way to utilize PEQ resources, especially for achieving smoother integration in the crossover region. We do plan to introduce time calibration, level adjustment, and crossover optimization features in future updates to allow for more precise system tuning.

Currently, the Sub Pro’s EQ range is set from 30Hz to...

jiaxin.li (WiiM) · Jul 30, 2025

slartibartfast said:
It appears you might have missed my question in post #174

S

Post in thread 'Introducing WiiM Sub Pro: Experience Bass Like Never Before'

Jul 29, 2025

jiaxin.li (WiiM) said:

Hello, thank you very much for sharing such a detailed and insightful perspective!

The approach you suggested—pairing first, then performing time alignment, level matching, and crossover optimization before running RoomFit—makes a lot of sense. It’s definitely a more efficient way to utilize PEQ resources, especially for achieving smoother integration in the crossover region. We do plan to introduce time calibration, level adjustment, and crossover optimization features in future updates to allow for more precise system tuning.

Currently, the Sub Pro’s EQ range is set from 30Hz to...

Click to expand...

slartibartfast

Thank you very much for your feedback! Currently, subwoofer and speaker synchronization is handled using the device’s built-in microphone, which provides basic time alignment in most usage scenarios. However, we recognize that for more demanding listening environments, using a microphone placed at the listening position could significantly improve synchronization accuracy and overall sound performance.
We take this suggestion seriously and are currently evaluating more advanced technical solutions, with the goal of further enhancing calibration accuracy and user experience in future updates.

Mr Ee · Jul 30, 2025

jiaxin.li (WiiM) said:
Currently, subwoofer and speaker synchronization is handled using the device’s built-in microphone,

jiaxin.li (WiiM) said:
a microphone placed at the listening position...

Please be explicit - device is rather ambiguous, state exactly which device.
The first quote implied to me that 'device' meant the phone/tablet running the wiim app.
But as the phone/tablet would likely be at the listening position then the second quote implies that it's not the home app device, and therefore that the subwoofer has a mic and that is used.

Introducing WiiM Sub Pro: Experience Bass Like Never Before

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What makes WiiM Sub Pro stand out?

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