Tech Tuesday: Deep Dive into Room Correction

[slartibartfast]

Is WHA confusing twenty with twelve?

It's doing something odd. I'll try some different values if I get a chance.

 

[slartibartfast]

I’ve realised that i bought and have been using the iMM-6 with converter cables a few months ago based on a comment i’d seen a a forum discussing housecurve. Is the 6c the better choice for room calibration? I’m using it with the calibration file so it should be corrected

How do you know what effect the converter cable has on the frequency response? You might be lucky but one I bought rolled off at low frequencies.

 

[canard]

How do you know what effect the converter cable has on the frequency response? You might be lucky but one I bought rolled off at low frequencies.

we don't know what is behind the rc mode...maybe just max limits set in the algorithm...
you should perform this same test more in the high frequencies and more reasonable values than this 20db

 

[slartibartfast]

we don't know what is behind the rc mode...maybe just max limits set in the algorithm...
you should perform this same test more in the high frequencies and more reasonable values than this 20db

By the way you quoted the wrong post . I'll try a few different values at different frequencies.

 

[canard]

By the way you quoted the wrong post . I'll try a few different values at different frequencies.

addressing you I just took your last message knowing that you would understand...
(Low frequency measurements are always difficult...)

 

[Wiimer]

we don't know what is behind the rc mode...maybe just max limits set in the algorithm...
you should perform this same test more in the high frequencies and more reasonable values than this 20db

Yeah, the maximum gain of RC is 12.5 dB, so the calibration limit of 12 dB is predictable

 

[slartibartfast]

Yeah, the maximum gain of RC is 12.5 dB, so the calibration limit of 12 dB is predictable

Good point, I'll try 10dB

 

[Giro413]

After many trials and error attempts, I have decided to wait for room correction to include L/R correction + sub before I give it another go. With the current stereo room correction with sub I cannot seem to get a better sound than without it. I try to listen with RC on for a while, but always come to the conclusion that it sounds better without it. I highly doubt that my room is perfect as is, and I would think that even the best rooms could be enhanced by just the right rc. So far I am getting way beter results with sound absorbing panels and no correction. When I say results, I am referring to better sound in my ears - no measurements.

 

[slartibartfast]

After many trials and error attempts, I have decided to wait for room correction to include L/R correction + sub before I give it another go. With the current stereo room correction with sub I cannot seem to get a better sound than without it. I try to listen with RC on for a while, but always come to the conclusion that it sounds better without it. I highly doubt that my room is perfect as is, and I would think that even the best rooms could be enhanced by just the right rc. So far I am getting way beter results with sound absorbing panels and no correction. When I say results, I am referring to better sound in my ears - no measurements.

Can you post a screenshot of the response measured by WiiM room correction? What was the frequency range for room correction? I would like to try acoustic panels but I think they would be even more trial and error for me

 

[slartibartfast]

Yeah, the maximum gain of RC is 12.5 dB, so the calibration limit of 12 dB is predictable

OK I changed the calibration up to 90Hz to -10dB and the same for 4kHz to 8kHz. Everything else set to 0dB. Now the results make sense and the step looks like 10dB

 

[Wiimer]

OK I changed the calibration up to 90Hz to -10dB and the same for 4kHz to 8kHz. Everything else set to 0dB. Now the results make sense and the step looks like 10dB

View attachment 17411
View attachment 17412

Perfect test.
Thank you so much.

# I seem to be unable to select the Good button emoji .
I give you ""

 

[slartibartfast]

I compared a room correction from WiiM with one from REW using the B&K target. Blue is REW, Red is WiiM. You can see the WiiM RC has filled the dips slightly but only by 2-3dB. The low frequencies are noticeably lower in the WiiM curve indicating that balance between low and high frequencies isn't quite right. I used a range of 20-700Hz. Not bad though.

View attachment 17353

Going back to the REW vs WiiM comparison I added the WiiM filter values to the REW measurement graph and the low frequencies definitely do not follow the B&K target curve. You can see the blue line is completely below the target at frequencies below around 150Hz. The first graph uses VAR smoothing and the second uses 1/12th octave smoothing.

 

[Bismarck]

This morning the WiiM app for iOS was finally updated on my iPad.
The updated version supports external measurement microphones with the possibility of loading their corresponding calibration file.
I ran the parametric equalization procedure within the WiiM app twice (setting the equalization range to 30–16,000).
The first time I used the iPad’s internal microphone, and the second time I used an external Umik-1, loading its corresponding calibration file.
In both cases, the result was good, but the equalization performed using the calibrated external microphone produced, at least to my ears, a much better outcome - especially at the extremes of the frequency range.
In my opinion, the basses came out noticeably rounder and more controlled and less “stretched,” while the highs were much warmer and more natural and less “harsh.”
On the other side, my subjective evaluation seems to be objectively confirmed examining the filters: there is a more pronounced average attenuation in the low-frequency range (which, without equalization, showed a decidedly high level) when using the Umik rather than using the iPad’s microphone, while the high-frequency range (which, without equalization, exhibited a slightly declining level) is, on average, less boosted when using the Umik.
I think that these effects are due to the Umik’s better response at the extremes of the frequency range and, consequently, to a more “realistic” operation of the correction algorithm.
I am getting ready to perform objective measurements with REW.
Just my two cents...

 

[GarthTheChicken]

How do you know what effect the converter cable has on the frequency response? You might be lucky but one I bought rolled off at low frequencies.

That’s why i was asking if it’s worth buying the c version. I would still need an adapter to go from usb to lightning

 

[slartibartfast]

That’s why i was asking if it’s worth buying the c version. I would still need an adapter to go from usb to lightning

Some users have reported good results with the iMM6 connected via a Google 3.5mm to USB adaptor but the only way to know for sure is to compare results against a USB mic.

 

[WiiM Team]

I just tried the calibration file import for my UMIK-2 (because it actually needs more correction than my UMIK-1). No comparison, no details so far. But the result was the most reasonable looking with my WiiM Amp Pro.

No crazy low Q boost anymore, so cal file.import turns out to address two topics in one go. Now I need just more time to play around with this.

While WHA 3.1.3 brought this long awaited feature it took away the balance slider for me.

Hi Harkpabst,

This is a known issue with the latest Android app. We will release an updated version to address it and restore the Volume Balance feature.

 

[slartibartfast]

Hi Harkpabst,

This is a known issue with the latest Android app. We will release an updated version to address it and restore the Volume Balance feature.

Strange that the issue doesn't affect everyone then. I still have the balance control.

 

[Maurizio]

Strange that the issue doesn't affect everyone then. I still have the balance control.

Yes, it's really weird. I still have the slider too

 

[Wiimer]

The balance slider seems to have disappeared only in Amp Pro; could it be related to the disappearance of the Dolby icon?

 

[Vignus]

I have followed all the good advises I received on this forum, but my RC still looks weird to me and I really hope I can get some extra help here.
To recap, I'm now using a Dayton iMM-6C external mic with the calibration file, connected to my tablet or to my phone.

I've set B&K Target Curve, Freq 30.0 to 4000.0 Hz, Smoothing 1/6 Octave and measured with stereo, one or 3 swipes. Given that my room has bad audio peakes up to around 100Hz, I would expect everything below that range to be reduced. But below's what I get. I wander if I'm doing something wrong... any help?