How to think about room correction settings like frequency range and gain?

[dominikz]

Unfortunately, I don't have the option to move the subwoofer, let alone put it in a corner. You can't see it in the photo, but I have a wifi router in the corner.

That is unfortunate, but understandable. I'd at least try to boost the subwoofer level then, since at the moment you don't seem to have a lot of bass below 70Hz. Was the subwoofer turned on when you did the measurement? If not, I'd suggest to repeat with the subwoofer on and post results.

Should I have the subwoofer on or off during room correction?

As mentioned above, the subwoofer should be on when running room correction.

So how do I set the parameters for a new room correction measurement in this case?

Please see above comments first; the answers may influence optimal RC parameter selection.

 

[canard]

After having tested the Min Gain and Max Gain RC controls introduced in WHA 3.1.8 more extensively I have to unfortunately report that the current RC implementation doesn't really handle well low values of Max Gain.

I.e. if you set Max Gain to 0,5 dB (minimum currently allowed) RC will spend most of the PEQ bands stacking such low-gain filters one on top of the other - which is a very inefficient use of the available EQ (example 1, example 2, example 3).

Therefore I have to revise my Min/Max Gain proposed values; these are the values that I'd use with the current RC implementation:

• Min Gain: -12.0dB
• Max Gain: +3.0 dB to start (but even higher values might be needed in case you notice multiple filters stacking at the same frequency )

I've already raised a support ticket to @WiiM Support about this and made a few suggestions for potential improvement:

• Consider supporting Max Gain value of "0 dB" - i.e. with this setting the RC algorithm would only use negative-gain PEQ filters.
• Assume that if a person limits Max Gain to a low value they are OK if some dips don't match the target so the RC algorithm should in general avoid stacking multiple positive-gain filters at the same frequency.
• Always prioritize cutting peaks over boosting dips - i.e. assign more PEQ bands to negative-gain filters over positive-gain filters. People are simply more sensitive to peaks than dips so it makes sense to focus on fixing peaks as well as possible.
• Consider implementing separate controls for Individual Max Gain and Overall Max Gain (like Individual Max Boost and Overall Max Boost controls in REW).
• Consider implementing separate controls for Boost Max Q and Cut Max Q - i.e. to be able to have sharp/precise cut filters (e.g. Q up to 10) to handle severe resonances, but only gradual boost filters (e.g. Q up to 3) to avoid any chance of audible ringing.
• Consider implementing "basic" and "expert" view in the RC settings. "Basic" view might only expose a few parameters (e.g. target curve, frequency range and mic calibration file loader), while "Expert" view would expose all of config parameters for fine-tuning by advanced users.

@WiiM Team and @WiiM Support I hope you will consider at least some of these suggestions, and I'd appreciate if you could provide some thoughts/feedback. Thanks in advance!

(A small interesting option would be the production of a "rew" data of the measurement exportable in rew etc for deferred "expert" processing)

 

[harkpabst]

Therefore I have to revise my Min/Max Gain proposed values; these are the values that I'd use with the current RC implementation:

• Min Gain: -12.0dB
• Max Gain: +3.0 dB to start (but even higher values might be needed in case you notice multiple filters stacking at the same frequency )

I came to the same conclusion for now.

Another area where the algorithm could use some tweaking (I think) is the level used for matching the desired target curve. I'm under the impression that the area respected for matching is tied to the frequency range chosen for correction. If so, this isn't necessarily ideal and does not always result in the least amount of positive gain.

Unfortunately, if no calibration file has been used the usable frequency range of the current mic is not really known. Trying to match over a frequency range broader than the correction range could end up relying on measuring errors like the well known peak around 8 kHz (or vanishing bass response) with many built-in microphones.

These errors will apply anyway if the users decides to run RC more or less full range, although the mic is not even up to it.

 

[Adam205]

Je to nešťastné, ale pochopiteľné. Potom by som sa aspoň pokúsil zvýšiť úroveň subwoofera, pretože v súčasnosti sa nezdá, že by ste mali veľa basov pod 70 Hz. Bol pri meraní zapnutý subwoofer? Ak nie, navrhujem opakovať so zapnutým subwooferom a uverejňovať výsledky.

Ako je uvedené vyššie, pri korekcii miestnosti by mal byť subwoofer zapnutý.

Najprv si pozrite vyššie uvedené komentáre; odpovede môžu ovplyvniť optimálny výber parametrov RC.

 

[dominikz]

@Adam205 Let me first start by saying that it is really unusual for a system with a subwoofer to have so little low bass. The response looks as if the subwoofer is deactivated. Not sure where is the issue, but are you absolutely certain the sub was turned on and working when you did the above measurements?

If you are sure the sub was enabled and set to sufficient volume, and if you believe the response in images above is the best you can get in your room, then I'd suggest to try the following RC settings:
Target: B&K
Freq: 65 - 250 Hz
Min gain: -12 dB
Max Gain: 3 dB
Max Q: 10
Smoothing: 1/12
Precision Room Correction: disabled

 

[Adam205]

Should I try turning the subwoofer up to maximum? I remember that during the next calibration at Sony they required turning the subwoofer up to maximum.

 

[dominikz]

Should I try turning the subwoofer up to maximum? I remember that during the next calibration at Sony they required turning the subwoofer up to maximum.

IMHO you need to turn the subwoofer up significantly higher than it is set now, but I can't tell you if that would be maximum level or lower than that.
You should turn it up until you see in RC results that the subwoofer is a bit higher in level than your loudspeakers. Then WiiM RC will have a healthier bass level to work with.

 

[MCG555]

Should I try turning the subwoofer up to maximum? I remember that during the next calibration at Sony they required turning the subwoofer up to maximum.

Someting is totally wrong!
I would never put the Sub to maximum!!
On my small B&W subs I have it maybe on 30% and that’s loud enough for a big room!
Check your environment!
1. Does the sub work? Do you hear it? Does the membrane move?
2. Are the settings correct? Is the cross frequeny really 80Hz or is this somekind of low-pass filter? Check the technical info!

 

[Wiimer]

Should I try turning the subwoofer up to maximum? I remember that during the next calibration at Sony they required turning the subwoofer up to maximum.

Are you using the built-in microphone on your Android phone?
If so, I guess excessive roll-off of bass (and possibly treble peaks) is a predictable result. What is your phone model?

 

[Wiimer]

Should I try turning the subwoofer up to maximum? I remember that during the next calibration at Sony they required turning the subwoofer up to maximum.

This was measured by placing the phone on the floor near the right side Sub. It is very similar to yours. Many similar photos have been posted in past RC threads. Depending on the phone used, the results for bass and treble can be different, but I think you will get relatively close results in the mid-range. (also it is not impossible to find peaks and dips in the bass range, even with the built-in mic.)



Next, Here are the results from the same phone with the IMM-6C mic installed (with the mic in the same position).



Comparing the internal mic and the external mic, I see that the results are close between 75Hz-4kHz.


#Another thing to note is that Android produces different results in the low frequencies on some models, even with an external mic. This is a very tricky issue. Therefore, I think need to compare several models, use a PC to measure, and use own ears to adjust the low-frequency balance. (I have done so.)

This is a comparison I recently made between my Xiaomi pad 7 and Galaxy Tab S8+. Both were measured from the exact same position using the IMM-6C mic.



When I first saw this, suspected I had made a mistake. However, no matter how many times measured it, the results were exactly the same.

 

[dominikz]

This was measured by placing the phone on the floor near the right side Sub. It is very similar to yours. Many similar photos have been posted in past RC threads. Depending on the phone used, the results for bass and treble can be different, but I think you will get relatively close results in the mid-range. (also it is not impossible to find peaks and dips in the bass range, even with the built-in mic.)
View attachment 20191


Next, Here are the results from the same phone with the IMM-6C mic installed (with the mic in the same position).

View attachment 20192

Comparing the internal mic and the external mic, I see that the results are close between 75Hz-4kHz.


#Another thing to note is that Android produces different results in the low frequencies on some models, even with an external mic. This is a very tricky issue. Therefore, I think need to compare several models, use a PC to measure, and use own ears to adjust the low-frequency balance. (I have done so.)

This is a comparison I recently made between my Xiaomi pad 7 and Galaxy Tab S8+. Both were measured from the exact same position using the IMM-6C mic.

View attachment 20193

When I first saw this, suspected I had made a mistake. However, no matter how many times measured it, the results were exactly the same.

Very nice analysis, thanks for sharing!

 

[Adam205]

Používate vstavaný mikrofón v telefóne s Androidom?
Ak áno, predpokladám, že nadmerné odvíjanie basov (a možno vysokých výšok) je predvídateľný výsledok. Aký je váš model telefónu?

Xiaomi Redmi Note 13

 

[Wiimer]

Xiaomi Redmi Note 13

Thanks for letting me know.
My phone is also Xiaomi, so it makes sense that the RC results are similar.

 

[Adam205]

Ďakujem, že si mi dal vedieť.
Môj telefón je tiež Xiaomi, takže dáva zmysel, že výsledky RC sú podobné.

So how do you recommend I do a room correction?

 

[Adam205]

 

[canard]

I think about it.. there is a very small function which should be installed on the RC mode.. just a timer to delay the launch of the capture. Sometimes useful...
;-)

 

[dominikz]

Ako mi teda odporúčate urobiť korekciu miestnosti?

Please post in English.

If your phone's microphone is misrepresenting the bass level by this much then your WiiM RC results simply won't be reliable, I'm afraid.
One solution would be to borrow or buy an external USB measurement microphone (with an individual calibration file) and use it to re-run RC. People mostly seem to use either miniDSP UMIK-1 or Dayton Audio IMM6c, as far as it seems to me.

Please have a look at these two help articles on the subject:

• Using an External Microphone for Room Correction
• Tutorial: Microphone Calibration File Import in WiiM Home

You could also try to run RC from a different mobile phone, but in most cases you again won't know how reliable your results are. People online suggest that iPhone mics give more consistent results, but I have no personal experience with them so can't say for sure.

With my Samsung Galaxy S23+ the bass level after RC was slightly off indicating some bass roll-off by the built-in mic (see examples here), but nowhere as much as @Wiimer demonstrated above.

 

[Wiimer]

Ako mi teda odporúčate urobiť korekciu miestnosti?

I agree with @dominikz.

In any case, I think you need to make sure that the Sub and speaker volume are aligned.
You can find this track on many streaming services, so play it.

110hz > 30hz step tones
(there is also 105hz > 25hz in the same album. Either one is fine)


It is a step tone that starts at 110hz and goes down by 10hz. Note that the volume is loud.

While playing this on repeat, check for large volume changes. Pay particular attention to the crossover frequency. If you do not hear a difference in volume, there is no major problem. At the same time, you can also check that your phone's microphone is not picking up bass.

However, I lack the expertise so and I am sure @dominikz will correct me if I am wrong.

With my Samsung Galaxy S23+ the bass level after RC was slightly off indicating some bass roll-off by the built-in mic (see examples here), but nowhere as much as @Wiimer demonstrated above.

Yes, my Galaxy Tab mic also picks up to 40Hz with no problem. I have tested several Xiaomi's and there was a huge difference between models...

 

[Adam205]

@Adam205 Let me first start by saying that it is really unusual for a system with a subwoofer to have so little low bass. The response looks as if the subwoofer is deactivated. Not sure where is the issue, but are you absolutely certain the sub was turned on and working when you did the above measurements?

If you are sure the sub was enabled and set to sufficient volume, and if you believe the response in images above is the best you can get in your room, then I'd suggest to try the following RC settings:
Target: B&K
Freq: 65 - 250 Hz
Min gain: -12 dB
Max Gain: 3 dB
Max Q: 10
Smoothing: 1/12
Precision Room Correction: disabled

I tried these parameters. Is it the same?

 

[MCG555]

I tried these parameters. Is it the same?

you should take priorities!
Is the sub producing sound??
Check the suggestions above…