KEF LS60 Room Correction Showdown: REW MMM vs. Wiim Ultra—A Data-Driven Analysis

[Dako]

1. Introduction and Background​

Room acoustics play a pivotal role in perceived audio quality in home listening environments. Of particular importance are resonant frequencies—or room modes—that commonly arise in rectangular rooms. These modes often lead to significant boosts or cuts in specific frequency bands, especially in the low-frequency region. Effective room correction aims to minimize the impact of these modal peaks and dips to provide a flatter, more accurate frequency response.

The following equipment was used:

• Speakers: KEF LS60
• Streamer: Wiim Ultra (with coaxial output to KEF LS60)
• Subwoofer: KEF KF92 (crossover at 60 Hz)
• Microphone: Umik-1 (USB measurement microphone)

The listening room is rectangular, and based on previous tests and known theoretical properties of such rooms, primary room modes appear at approximately 25 Hz and 60 Hz. In practice, a strong peak of about +8 dB occurs around 60 Hz, primarily from subwoofer excitation. Since subwoofer placement options are limited, employing parametric equalization (PEQ) or an effective room correction system is essential for reducing excessive bass buildup.

---

2. Methods​

2.1 Measurement Protocol (REW MMM)​

Measurements were performed using the Moving Microphone Method (MMM) in REW (Room EQ Wizard). MMM involves continuously moving the microphone within the listening area while generating test signals to capture an averaged response that accounts for spatial variations in the room. This approach is known to provide more robust correction data, particularly at lower frequencies where room modes dominate. For details on the MMM technique, see AudioScienceReview Forum reference. Smoothing VAR.

2.2 Correction Strategies​

1. Uncorrected (Blue Curve)
   Represents the baseline measurement of the KEF LS60 and KF92 subwoofer without any equalization or room correction.
2. REW MMM Correction (Green Curve)
   A correction filter was derived in REW, targeting frequencies below 300 Hz to address major room modes. This filter was then applied to the system to tame peaks at ~24 Hz, ~60 Hz, and between 100–200 Hz.
3. Wiim Room Correction (Purple Curve)
   Wiim Ultra’s built-in room correction was used with an iPhone 13 as the measurement device. For testing purpose I selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

2.3 Target Curve and Subwoofer Integration​

Harman target curve was adopted, which slightly boosts low frequencies while remaining relatively flat through the midrange and treble. The subwoofer crossover was set at 60 Hz to integrate with the KEF LS60 main speakers.

---

3. Results and Discussion​

3.1 Uncorrected Response (Blue Curve)​

The blue curve (Figure 1) reveals substantial peaks near 24 Hz and 60 Hz, along with additional irregularities between 100 and 200 Hz. Subjectively, these peaks produce a “boomy” or “heavy” bass characteristic. The 60 Hz peak is particularly problematic, causing bass overhang and masking details in the upper bass region.

3.2 REW MMM Correction (Green Curve)​

The green curve (Figure 2) demonstrates a significantly more even response below 300 Hz once corrections are applied. By attenuating the 24 Hz, 60 Hz and around 100 to 200 hz peaks, the overall bass character improves. Subjective listening confirmed a reduction in boominess and an increased sense of clarity, allowing the KEF LS60’s inherent qualities to come through.

3.3 Wiim Room Correction (Purple Curve)​

The purple curve (Figure 3) shows the outcome of Wiim Ultra’s auto-correction feature. Contrary to expectation, the system boosted frequencies between 20 and 70 Hz rather than attenuating them, exacerbating the existing room modes. It also introduced noticeable changes around 1 kHz and a high-frequency lift of approximately +4 dB. Subjectively, this yielded an overly bass-heavy and excessively bright tonality, diverging considerably from standard room correction targets. It appears that Wiim’s current algorithm attempts a full-range correction but may lack sufficient resolution or measurement precision to accurately handle complex room interactions.

---

4. Conclusions​

4.1 Effectiveness of Methods​

• REW MMM-based Correction: Offers a more controlled low-frequency response, aligning closely with recognized best practices for room correction (targeting problematic modes below ~300 Hz).
• Wiim Ultra Correction: Full-range correction in its current form seems suboptimal, particularly in challenging low-frequency environments. The resulting boosts and treble enhancements suggest it is neither designed nor optimized for precise sub-300 Hz corrections in typical rooms.

4.2 Recommendations​

1. Limited Frequency Range Correction: Focus correction efforts between roughly 40 Hz and 300–400 Hz to mitigate the most problematic modes without over-processing mid and high frequencies.
2. Refinement of Wiim Algorithm: Future firmware updates or user-selectable target curves could improve Wiim’s utility as a room correction solution. Until then, using a dedicated EQ tool (like REW-generated filters) may yield more accurate and predictable results.
3. Verification Through Multiple Measurements: Continue using techniques such as MMM to capture representative spatial responses. This approach helps prevent over-correction or erroneous boosts in response to single-point measurements.

 

[slartibartfast]

1. Introduction and Background​

Room acoustics play a pivotal role in perceived audio quality in home listening environments. Of particular importance are resonant frequencies—or room modes—that commonly arise in rectangular rooms. These modes often lead to significant boosts or cuts in specific frequency bands, especially in the low-frequency region. Effective room correction aims to minimize the impact of these modal peaks and dips to provide a flatter, more accurate frequency response.

The following equipment was used:

• Speakers: KEF LS60
• Streamer: Wiim Ultra (with coaxial output to KEF LS60)
• Subwoofer: KEF KF92 (crossover at 60 Hz)
• Microphone: Umik-1 (USB measurement microphone)

The listening room is rectangular, and based on previous tests and known theoretical properties of such rooms, primary room modes appear at approximately 25 Hz and 60 Hz. In practice, a strong peak of about +8 dB occurs around 60 Hz, primarily from subwoofer excitation. Since subwoofer placement options are limited, employing parametric equalization (PEQ) or an effective room correction system is essential for reducing excessive bass buildup.

---

2. Methods​

2.1 Measurement Protocol (REW MMM)​

Measurements were performed using the Moving Microphone Method (MMM) in REW (Room EQ Wizard). MMM involves continuously moving the microphone within the listening area while generating test signals to capture an averaged response that accounts for spatial variations in the room. This approach is known to provide more robust correction data, particularly at lower frequencies where room modes dominate. For details on the MMM technique, see AudioScienceReview Forum reference. Smoothing VAR.

2.2 Correction Strategies​

1. Uncorrected (Blue Curve)
   Represents the baseline measurement of the KEF LS60 and KF92 subwoofer without any equalization or room correction.
2. REW MMM Correction (Green Curve)
   A correction filter was derived in REW, targeting frequencies below 300 Hz to address major room modes. This filter was then applied to the system to tame peaks at ~24 Hz, ~60 Hz, and between 100–200 Hz.
3. Wiim Room Correction (Purple Curve)
   Wiim Ultra’s built-in room correction was used with an iPhone 13 as the measurement device. The user selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

2.3 Target Curve and Subwoofer Integration​

Harman target curve was adopted, which slightly boosts low frequencies while remaining relatively flat through the midrange and treble. The subwoofer crossover was set at 60 Hz to integrate with the KEF LS60 main speakers.

---

3. Results and Discussion​

3.1 Uncorrected Response (Blue Curve)​

The blue curve (Figure 1) reveals substantial peaks near 24 Hz and 60 Hz, along with additional irregularities between 100 and 200 Hz. Subjectively, these peaks produce a “boomy” or “heavy” bass characteristic. The 60 Hz peak is particularly problematic, causing bass overhang and masking details in the upper bass region.
View attachment 15838

3.2 REW MMM Correction (Green Curve)​

The green curve (Figure 2) demonstrates a significantly more even response below 300 Hz once corrections are applied. By attenuating the 24 Hz, 60 Hz and around 100 to 200 hz peaks, the overall bass character improves. Subjective listening confirmed a reduction in boominess and an increased sense of clarity, allowing the KEF LS60’s inherent qualities to come through.
View attachment 15839

3.3 Wiim Room Correction (Purple Curve)​

The purple curve (Figure 3) shows the outcome of Wiim Ultra’s auto-correction feature. Contrary to expectation, the system boosted frequencies between 20 and 70 Hz rather than attenuating them, exacerbating the existing room modes. It also introduced noticeable changes around 1 kHz and a high-frequency lift of approximately +4 dB. Subjectively, this yielded an overly bass-heavy and excessively bright tonality, diverging considerably from standard room correction targets. It appears that Wiim’s current algorithm attempts a full-range correction but may lack sufficient resolution or measurement precision to accurately handle complex room interactions.
View attachment 15841

---

4. Conclusions​

4.1 Effectiveness of Methods​

• REW MMM-based Correction: Offers a more controlled low-frequency response, aligning closely with recognized best practices for room correction (targeting problematic modes below ~300 Hz).
• Wiim Ultra Correction: Full-range correction in its current form seems suboptimal, particularly in challenging low-frequency environments. The resulting boosts and treble enhancements suggest it is neither designed nor optimized for precise sub-300 Hz corrections in typical rooms.

4.2 Recommendations​

1. Limited Frequency Range Correction: Focus correction efforts between roughly 40 Hz and 300–400 Hz to mitigate the most problematic modes without over-processing mid and high frequencies.
2. Refinement of Wiim Algorithm: Future firmware updates or user-selectable target curves could improve Wiim’s utility as a room correction solution. Until then, using a dedicated EQ tool (like REW-generated filters) may yield more accurate and predictable results.
3. Verification Through Multiple Measurements: Continue using techniques such as MMM to capture representative spatial responses. This approach helps prevent over-correction or erroneous boosts in response to single-point measurements.

I am surprised the WiiM RC boosted the low frequencies so much. From the screenshot it looks like the original measurement was incorrect. Did you try repeating it making sure PEQ is turned off first?

 

[Dako]

I am surprised the WiiM RC boosted the low frequencies so much. From the screenshot it looks like the original measurement was incorrect. Did you try repeating it making sure PEQ is turned off first?

Yes, I've tried multiple times, and I always get the same result from the WiiM correction. I suspect the iPhone’s microphone isn’t very accurate below 40 Hz. When I set the correction to start at 40 Hz instead of 20 Hz, the problem isn’t nearly as pronounced.

 

[Wiimer]

1. Introduction and Background​

Room acoustics play a pivotal role in perceived audio quality in home listening environments. Of particular importance are resonant frequencies—or room modes—that commonly arise in rectangular rooms. These modes often lead to significant boosts or cuts in specific frequency bands, especially in the low-frequency region. Effective room correction aims to minimize the impact of these modal peaks and dips to provide a flatter, more accurate frequency response.

The following equipment was used:

• Speakers: KEF LS60
• Streamer: Wiim Ultra (with coaxial output to KEF LS60)
• Subwoofer: KEF KF92 (crossover at 60 Hz)
• Microphone: Umik-1 (USB measurement microphone)

The listening room is rectangular, and based on previous tests and known theoretical properties of such rooms, primary room modes appear at approximately 25 Hz and 60 Hz. In practice, a strong peak of about +8 dB occurs around 60 Hz, primarily from subwoofer excitation. Since subwoofer placement options are limited, employing parametric equalization (PEQ) or an effective room correction system is essential for reducing excessive bass buildup.

---

2. Methods​

2.1 Measurement Protocol (REW MMM)​

Measurements were performed using the Moving Microphone Method (MMM) in REW (Room EQ Wizard). MMM involves continuously moving the microphone within the listening area while generating test signals to capture an averaged response that accounts for spatial variations in the room. This approach is known to provide more robust correction data, particularly at lower frequencies where room modes dominate. For details on the MMM technique, see AudioScienceReview Forum reference. Smoothing VAR.

2.2 Correction Strategies​

1. Uncorrected (Blue Curve)
   Represents the baseline measurement of the KEF LS60 and KF92 subwoofer without any equalization or room correction.
2. REW MMM Correction (Green Curve)
   A correction filter was derived in REW, targeting frequencies below 300 Hz to address major room modes. This filter was then applied to the system to tame peaks at ~24 Hz, ~60 Hz, and between 100–200 Hz.
3. Wiim Room Correction (Purple Curve)
   Wiim Ultra’s built-in room correction was used with an iPhone 13 as the measurement device. The user selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

2.3 Target Curve and Subwoofer Integration​

Harman target curve was adopted, which slightly boosts low frequencies while remaining relatively flat through the midrange and treble. The subwoofer crossover was set at 60 Hz to integrate with the KEF LS60 main speakers.

---

3. Results and Discussion​

3.1 Uncorrected Response (Blue Curve)​

The blue curve (Figure 1) reveals substantial peaks near 24 Hz and 60 Hz, along with additional irregularities between 100 and 200 Hz. Subjectively, these peaks produce a “boomy” or “heavy” bass characteristic. The 60 Hz peak is particularly problematic, causing bass overhang and masking details in the upper bass region.
View attachment 15838

3.2 REW MMM Correction (Green Curve)​

The green curve (Figure 2) demonstrates a significantly more even response below 300 Hz once corrections are applied. By attenuating the 24 Hz, 60 Hz and around 100 to 200 hz peaks, the overall bass character improves. Subjective listening confirmed a reduction in boominess and an increased sense of clarity, allowing the KEF LS60’s inherent qualities to come through.
View attachment 15839

3.3 Wiim Room Correction (Purple Curve)​

The purple curve (Figure 3) shows the outcome of Wiim Ultra’s auto-correction feature. Contrary to expectation, the system boosted frequencies between 20 and 70 Hz rather than attenuating them, exacerbating the existing room modes. It also introduced noticeable changes around 1 kHz and a high-frequency lift of approximately +4 dB. Subjectively, this yielded an overly bass-heavy and excessively bright tonality, diverging considerably from standard room correction targets. It appears that Wiim’s current algorithm attempts a full-range correction but may lack sufficient resolution or measurement precision to accurately handle complex room interactions.
View attachment 15841

---

4. Conclusions​

4.1 Effectiveness of Methods​

• REW MMM-based Correction: Offers a more controlled low-frequency response, aligning closely with recognized best practices for room correction (targeting problematic modes below ~300 Hz).
• Wiim Ultra Correction: Full-range correction in its current form seems suboptimal, particularly in challenging low-frequency environments. The resulting boosts and treble enhancements suggest it is neither designed nor optimized for precise sub-300 Hz corrections in typical rooms.

4.2 Recommendations​

1. Limited Frequency Range Correction: Focus correction efforts between roughly 40 Hz and 300–400 Hz to mitigate the most problematic modes without over-processing mid and high frequencies.
2. Refinement of Wiim Algorithm: Future firmware updates or user-selectable target curves could improve Wiim’s utility as a room correction solution. Until then, using a dedicated EQ tool (like REW-generated filters) may yield more accurate and predictable results.
3. Verification Through Multiple Measurements: Continue using techniques such as MMM to capture representative spatial responses. This approach helps prevent over-correction or erroneous boosts in response to single-point measurements.

Thanks for a very interesting post .

Pardon my layman's question, but is the sweep you used for measurements 1 and 2 from WiiM's Room Correction Audio? Or are they generated by REW?

If the latter, is it possible to retest 1 and 2 with WiiM's Sweep Audio?

 

[Incognito]

For testing purpose I selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

Dako, Thanks for the analysis. I would be interested in seeing the the analysis of the WiiM room correction set at the same correction frequencies as the REW MMM, 20-300HZ. The analysis shown appears to be comparing 'apples to oranges'.

 

[slartibartfast]

Yes, I've tried multiple times, and I always get the same result from the WiiM correction. I suspect the iPhone’s microphone isn’t very accurate below 40 Hz. When I set the correction to start at 40 Hz instead of 20 Hz, the problem isn’t nearly as pronounced.

I thought you would have used the UMIK-1 as an external mic for the WiiM RC.

 

[slartibartfast]

Thanks for a very interesting post .

Pardon my layman's question, but is the sweep you used for measurements 1 and 2 from WiiM's Room Correction Audio? Or are they generated by REW?

If the latter, is it possible to retest 1 and 2 with WiiM's Sweep Audio?

I think the REW moving mic.measirements would have been using pink noise, not a sweep.

 

[Dako]

Dako, Thanks for the analysis. I would be interested in seeing the the analysis of the WiiM room correction set at the same correction frequencies as the REW MMM, 20-300HZ. The analysis shown appears to be comparing 'apples to oranges'.

I did a full range measurement in REW MMM as well but as the LS60 is a neutral speaker there are simply no correction happening above 300 hz. And that's the point of this analysis, be careful to use Wiims RC as its simply not accurate enough yet...

 

[Dako]

I think the REW moving mic.measirements would have been using pink noise, not a sweep.

Correct!

 

[Wiimer]

I thought you would have used the UMIK-1 as an external mic for the WiiM RC.

Me too.

 

[Dako]

Me too.

Im writing the information here:

1. Wiim Room Correction (Purple Curve)
   Wiim Ultra’s built-in room correction was used with an iPhone 13 as the measurement device. For testing purpose I selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

 

[slartibartfast]

Im writing the information here:

1. Wiim Room Correction (Purple Curve)
   Wiim Ultra’s built-in room correction was used with an iPhone 13 as the measurement device. For testing purpose I selected a correction range of 20–20,000 Hz. This contrasts with the more typical approach of only correcting frequencies below ~300–400 Hz.

Maybe try with the UMIK to compare

 

[Incognito]

I did a full range measurement in REW MMM as well but as the LS60 is a neutral speaker there is no correction happening above 300 hz.

I guess what I was trying to get at is that it appears that the WiiM room correction has resolution limitations that might be mitigated by taking your advice to focus correction efforts below 400 Hz when using the WiiM room correction. I often see that advice here in the forum. Regardless, thanks for the post. As you have shown, more sophisticated methods often achieve more accurate results.

It appears that Wiim’s current algorithm attempts a full-range correction but may lack sufficient resolution or measurement precision to accurately handle complex room interactions.....

Limited Frequency Range Correction: Focus correction efforts between roughly 40 Hz and 300–400 Hz to mitigate the most problematic modes without over-processing mid and high frequencies.

 

[Dako]

Maybe try with the UMIK to compare

I agree, would be interesting. Right now, I’m using an iPhone 13 with only a Lightning port, so I can’t connect my Umik-1 without buying an adapter. Given that a lot of people still rely on the built-in iPhone mic for measurements, this analysis is meant to help others understand the potential pitfalls and use caution for the results.

 

[slartibartfast]

I agree, would be interesting. Right now, I’m using an iPhone 13 with only a Lightning port, so I can’t connect my Umik-1 without buying an adapter. Given that a lot of people still rely on the built-in iPhone mic for measurements, this analysis is meant to help others understand the potential pitfalls and use caution for the results.

I forgot about the Lightning port

 

[MCG555]

Thanks for the interesting measurements and report.

Not sure if this can count as reference, in my case WiiM RC never bosted bass!

• Wiim Ultra Correction: Full-range correction in its current form seems suboptimal, particularly in challenging low-frequency environments. The resulting boosts and treble enhancements suggest it is neither designed nor optimized for precise sub-300 Hz corrections in typical rooms.

Now, have you done measurements between 20Hz and 400Hz? It would be interesting.
In my case results in bass are great! However I encounter issues with frequenciesabove 4kHz (with the iphone 12).

 

[Vignus]

Very interesting thread for me, as I have done RC several times with different mics, different devices and different methods (1 sweep, multiple sweehenps, stereo, L/R), and it always ends up boosting my low frequencies, when in fact it isn't really needed, and making things much worse in the 20-80 Hz region. I have an Ultra.
I think RC isn't very refined yet and I hope WiiM IT guys will keep working on it until it works well.

 

[slartibartfast]

Very interesting thread for me, as I have done RC several times with different mics, different devices and different methods (1 sweep, multiple sweehenps, stereo, L/R), and it always ends up boosting my low frequencies, when in fact it isn't really needed, and making things much worse in the 20-80 Hz region. I have an Ultra.
I think RC isn't very refined yet and I hope WiiM IT guys will keep working on it until it works well.

If you don't move the mic there really shouldn't be any appreciable difference between a single sweep and multiple sweeps. Which mics did you try?

 

[Vignus]

If you don't move the mic there really shouldn't be any appreciable difference between a single sweep and multiple sweeps. Which mics did you try?

Thanks for trying to help, slartibartfast, but I've been through this discussion quite a few times on this forum, and I don't think it's the mic(s). Otherwise, different mics should give at least slightly different results, no?

 

[Wiimer]

Thanks for trying to help, slartibartfast, but I've been through this discussion quite a few times on this forum, and I don't think it's the mic(s). Otherwise, different mics should give at least slightly different results, no?

What kind of speakers are you using, and do they have Sub?

For example, if you have a small bookshelf and no Sub, the RC may tend to boost the low frequencies to an appropriate level.