Room Correction Beta firmware for WiiM Pro, Pro Plus and Amp - User Testing Experience

[harkpabst]

It honestly doesn't sound bright at any volume. Before the Harman curve did everyone have bleeding ears from listening to their flat systems? . What happens if the studio also uses a Harman curve at mastering time? You would end up with cascaded Harman curves in your listening room.

That's a misconception. The Harman curve is not something superimposed on otherwise linear reproduction to get rid of harsh treble. At least following the publications of Toole and Oliver it's almost more of a discovery than an invention.

Put a speaker system with (anechoic) linear on-axis response and (allegedly) desirable directivity in a typical living room and (measured in the MLP) you will end up with an average response similar to the Harman curve, superimposed (tonandegree) with room resonances and reflections.

It's not a sound effect.

 

[cooky560]

Human ears do not perceive all sounds on a perfectly flat curve. Different frequencies are perceived differently. Flat might be a technical accomplishment but it will not sound right to most ears.

 

[harkpabst]

Interestingly, I wonder whether the old iPad curve with the big treble bump is actually closer to reality while the fairly new iPhone 14 is the one losing the plot above a certain frequency.

This is most certainly not the case. That bump is almost 20 dB above the average between 300 Hz and 3 kHz and it's inside the audible band. Nobody builds speakers like that and the measurements found by @MKUltra clearly proof it.

What we can learn so far is that iDevice microphones and/or their accompanying calibration data are far less reliable than some may think. That's a good reason to not use them for correction above ~3 kHz. Others have mentioned why it might be reasonable to restrict the upper limit even further.

It's not so clear, yet, what a reasonable lower limit would be. Your measurements below 60 Hz don't look completely off, but I still don't have much faith.

 

[slartibartfast]

That's a misconception. The Harman curve is not something superimposed on otherwise linear reproduction to get rid of harsh treble. At least following the publications of Toole and Oliver it's almost more of a discovery than an invention.

Put a speaker system with (anechoic) linear on-axis response and (allegedly) desirable directivity in a typical living room and (measured in the MLP) you will end up with an average response similar to the Harman curve, superimposed (tonandegree) with room resonances and reflections.

It's not a sound effect.

It must depend on the size of the room though and listening position. US rooms are probably much bigger than European rooms. With Monitor Audio speakers I am cutting treble slightly to get to flat.

 

[harkpabst]

Human ears do not perceive all sounds on a perfectly flat curve. Different frequencies are perceived differently. Flat might be a technical accomplishment but it will not sound right to most ears.

This point is often made but in how far does it matter?

If the reproduced sound pressure level was 100% identical to the original sound event, then we couldn't hear any difference, no matter if our own heating is linear or not.

We might just not be as sensitive to certain errors and this sensitivity might be different between individual humans.

 

[harkpabst]

It must depend on the size of the room though and listening position. US rooms are probably much bigger than European rooms. With Monitor Audio speakers I am cutting treble slightly to get to flat.

Absolutely. And that's one reason why it's not just exact science.

 

[Smartplug]

I turn off RC as it made sound worse and not improvement. The original beta firmware that was direct inverted was improvement and made my system sound great. Let say if the measured was 3db cut on 100hz the eq will boost 3db on 100hz in resulting flat response. Now, the latest algorithm doesn’t match everything from what was cut and boost.

 

[steadyshot]

I turn off RC as it made sound worse and not improvement. The original beta firmware that was direct inverted was improvement and made my system sound great. Let say if the measured was 3db cut on 100hz the eq will boost 3db on 100hz in resulting flat response. Now, the latest algorithm doesn’t match everything from what was cut and boost.

What do you mean by “direct inverted” ?

 

[Musician]

I got the beta on my Pro Plus today. Similar experience to everyone else, it results in a very dull & muffled sound. In my case the speakers (Piega Classic 3 with AMT tweeter) measure with a big bump in the treble which RC tries to cut, effectively cutting all details from the music.

If I have time tomorrow I'll compare with Homecurve using a couple of different iOS devices to see if the mics are bad etc... and send a report to WiiM.

It would be interesting to figure out if those speakers are just crazy on the high end and I got used to it a comparison session with good headphones is on the agenda... It could also be that my old iPad has a toasted mic

As i wrote earlier - you cannot correct anything with accuracy measuring from listeningposition above 200-300 Hz . The microphone must be calibrated and put 1 meter near the single measured speaker 200-20000 Hz to have a measurement thats the same as the ear/brain hears at listening position 4 meters away.

If every correction sounds bad, worse than before, your placement of the microphones are probably wrong or the microphones are inaccurate.

 

[bherren]

As i wrote earlier - you cannot correct anything measuring from listeningposition above 200-300 Hz . The microphone must be calibrated and put 1 meter near the single measured speaker 200-20000 Hz to have a measurement thats the same as the ear/brain hears at listening position 4 meters away.

If every correction sounds bad, worse than before, your placement of the microphones are probably wrong or the microphones are inaccurate.

The correction done by WiiM sounds bad with the microphone setup the way WiiM instructs to put it. As I wrote earlier this was a smoke test to see if the weird differences in measurements between devices are consistent (they are) and result in significant differences in automatic correction (they do). I will do more experiments including better/manual corrections along the lines you describe when I'm back home this weekend

 

[Smartplug]

What do you mean by “direct inverted” ?

Check post 234

 

[tjdressel]

I'll send a complete report to WiiM separately but I can already see a major difference between measurements between the iPad 6th gen and the iPhone 14 pro max, both using latest iOS. Here are screenshots with housecurve, wiim give somewhat similar results but I'm running out of time to play

First is iPad. You can see the crazy treble bump. The end result is that doing the correction with the iPad results in something completely muffled and dull. With the iPhone it's better but I feel I'm still losing too much details, it's quite aggressive at fitting the target curve, maybe too much

This will be the challenge with using a mobile device for room correction. It will be substantially worse on Android, at least Apple has tighter reign on the hardware.

Coming from a place of ignorance, are there any microphones you could plug directly into the mobile device? Like a calibrated/known electrical performance mic with a built in analogue to digital DAC that could be more reliable? Something inexpensive, like say $50?

 

[bherren]

This will be the challenge with using a mobile device for room correction. It will be substantially worse on Android, at least Apple has tighter reign on the hardware.

Coming from a place of ignorance, are there any microphones you could plug directly into the mobile device? Like a calibrated/known electrical performance mic with a built in analogue to digital DAC that could be more reliable? Something inexpensive, like say $50?

I just bought an IMM6 for $35 AUD, picking it up tomorrow it works with housecurve, but I don't think WiiM supports the use of such an external mic yet

 

[tjdressel]

This will be the challenge with using a mobile device for room correction. It will be substantially worse on Android, at least Apple has tighter reign on the hardware.

Coming from a place of ignorance, are there any microphones you could plug directly into the mobile device? Like a calibrated/known electrical performance mic with a built in analogue to digital DAC that could be more reliable? Something inexpensive, like say $50?

Should have read further, I see there absolutely is such a device!

 

[tjdressel]

I just bought an IMM6 for $35 AUD, picking it up tomorrow it works with housecurve, but I don't think WiiM supports the use of such an external mic yet

Roger, thx! This is the way.

 

[Brantome]

I just bought an IMM6 for $35 AUD, picking it up tomorrow it works with housecurve, but I don't think WiiM supports the use of such an external mic yet

And you can enter the PEQ values HouseCurve generated into the WiiM app directly

 

[canard]

integration of microphone calibration files into the app is their main interest.. therefore.... to be offered quickly....
(housecurve can do it? or just designed for use with the internal microphone of iphones? the arrival of the Dayton udb-c changes the situation a lot)

 

[MKUltra]

I just bought an IMM6 for $35 AUD, picking it up tomorrow it works with housecurve, but I don't think WiiM supports the use of such an external mic yet

IMM6 is analog, as far as I can remember, which means it's 100% dependent on whatever ADC you connect it to... and which may be subject to things like "smart" noise cancellation if it's a phone or a computer, etc.

Maybe an UMM6 would have been better :/

 

[sjuihagfisadhgfsodia]

I think the aim of rc shouldn't be like that of REW and all its features. After all we got fully custumizable REW for that.

The aim of rc should be some basic correction far from perfection. Theres are many variables and problems for it to be something else.

 

[canard]

I think the aim of rc shouldn't be like that of REW and all its features. After all we got fully custumizable REW for that.

The aim of rc should be some basic correction far from perfection. Theres are many variables and problems for it to be something else.

indeed.. ;-)
a "correct" and very integrated general public solution..
but will remain an approach to capture to be sufficiently "safe" to not do "worse".. "nerf de la guerre"....
multi-measurements, qualibration in the broad sense...etc
;-)
(but the option of dedicated software like inexpensive house curve and manual integration into the peq will perhaps remain the most obvious option)