Device for Equal Loudness/Fletcher Munson Curve? Do Any Speakers Adapt to This?

[j_j]

Hi again, and quick question. What weighting type should I use when measuring my SPL so I can apply the correct correction curve? In other words, what weighting type are the ISO curves based on? A, C or Z? I find that there is a lot of difference in the readings when changing weighting type. I think it should be C or Z but just checking.

Also, do the adjustment EQ curves refer to the average SPL or to the peak? I read in some of Bob Katz's comments that 83db is only for the "forte" passages.

It's not that simple. Your device must be data-dependent, and know the details of the system rendering the sound.

 

[o2so]

It's not that simple. Your device must be data-dependent, and know the details of the system rendering the sound.

Ok but I can't do that. I would like to have just a rough idea to build a static "loudness" filter for late night listening. I will not be using dynamic eq because I don't think this can be set up in roon. At night I listen at an average of about 65db C weighted, but peaks can be at 75db. Does it mean that I should use the -20db curve, or the -10db?

 

[dasdoing]

Ok but I can't do that. I would like to have just a rough idea to build a static "loudness" filter for late night listening. I will not be using dynamic eq because I don't think this can be set up in roon. At night I listen at an average of about 65db C weighted, but peaks can be at 75db. Does it mean that I should use the -20db curve, or the -10db?

for music I would set the loud level per ear. put it at a level where the music sounds best. a loud level you would use while givig a party. from there aply the correction curve that gives you desired level

 

[kyle_neuron]

Ok but I can't do that. I would like to have just a rough idea to build a static "loudness" filter for late night listening. I will not be using dynamic eq because I don't think this can be set up in roon. At night I listen at an average of about 65db C weighted, but peaks can be at 75db. Does it mean that I should use the -20db curve, or the -10db?

The original curves are all based on a Phon level centred at 1 kHz. An unweighted (Z) calibrated measurement can be used to match your listening level to the equivalent Phon level, ideally with RTA spectrum visibility and broadband pink noise or M-noise stimulus.

Then you can dial in the ELC for that listening level.

Having done this myself in various test setups from home to gigs though, I don’t think it’s a good idea. Especially not without a full assessment of the kit in use and the room itself. I’ll let you try it for yourself.

 

[pedrob]

I don't feel a need to adjust the frequency response with changes in volume.

I guess, if something is playing at a lower level, I expect to hear it with the psychoacoustic changes that come along with the lower level.

If "critically" listening, the volume will be in the flat zone anyway. So...


The "old" Fletcher Munson equal loudness curves:

View attachment 65760


I tried the ISO curve for my listening levels, didn't like the result with the recordings I played.

View attachment 65763

100dB low bass when listening at 45dB (a pretty low level) in the midrange? No thanks.

Analyzing those curves isn't wise as the amount of boost seems frightening.

Until recently I accepted frequency drop off at lower levels as the old loudness controls were way too much and ruined the listening experience.

Since I don't always listen at reference levels, I now enjoy hearing the full range at lower levels with current sophisticated methods. Although it did take me sometime to get accustomed to it as it just seemed wrong.

Now that my brain has accepted hearing full range at lower levels, when I turn it off I hate the frail sound.

 

[Chromatischism]

I don't feel a need to adjust the frequency response with changes in volume.

I guess, if something is playing at a lower level, I expect to hear it with the psychoacoustic changes that come along with the lower level.

If "critically" listening, the volume will be in the flat zone anyway. So...


The "old" Fletcher Munson equal loudness curves:

View attachment 65760


I tried the ISO curve for my listening levels, didn't like the result with the recordings I played.

View attachment 65763

100dB low bass when listening at 45dB (a pretty low level) in the midrange? No thanks.

Most loudness compensation algorithms don't add quite that much. Usually the bass boost is a more reasonable 5-10 dB.

But to your other point, whoever created your music makes certain assumptions about the playback levels you will use. If you stray from those playback levels, you won't hear it as they intended. So no, they did not intend for some details on the top and bottom to fade away when you decide to listen quietly.

 

[Chromatischism]

This should be taken care of when the recording is made, not when sound is reproduced.

It is both. Equal loudness is used by the creator of the music at a certain playback level. You need to use that same playback level to hear it as they did. Since that will not always be the case, we invented loudness compensation.

 

[ReaderZ]

It is both. Equal loudness is used by the creator of the music at a certain playback level. You need to use that same playback level to hear it as they did. Since that will not always be the case, we invented loudness compensation.

Ahh, I see your point, but since recording doesn't even give an intended listening level, how do you know how much should you compensate?

 

[Chromatischism]

Since there are no standards, it's just by your ears.

 

[o2so]

Ahh, I see your point, but since recording doesn't even give an intended listening level, how do you know how much should you compensate?

My understanding is that there are standards, however not necessarily these have been applied to all recordings.
Bob Katz's mastering guidelines recommend setting EACH monitor so that pink noise measures 83db at the listening spot (C weighted). Which means that when you listen stereo you would have about 85-86db at the listening spot. I use this as my reference and I find that it works well with most recordings. Yes results with loudness compensation are not perfect as there is some variability from record to record, but are certainly less imperfect than without compensation at all.

 

[o2so]

Audyssey's Dynamic EQ feature compensates for this. Ignore the levels on the left side. What you'll see is a shaping of the curve dependent on both frequency and master volume level.

View attachment 127459

Note that it does not exactly resemble the Fletcher + Munson curves in their extremity. I find you don't need quite as much as the raw research shows. The reasons for that likely include (my hypothesizing) some of it already "baked-in" by movie and music mastering engineers and room interactions lifting the bass naturally.

Are these curves automatically made by audissey or have you created these to suit your preferences?
I am asking because the compensation on the highs is much smaller than the one you obtain by subtracting ISO curves like @dasdoing has suggested

 

[dasdoing]

Are these curves automatically made by audissey or have you created these to suit your preferences?
I am asking because the compensation on the highs is much smaller than the one you obtain by subtracting ISO curves like @dasdoing has suggested

the iso doesn't cover the range above 12500. there are 2 solutions for this problem as seen here: https://hydrogenaud.io/index.php?topic=83607.msg722690#msg722690

 

[Chromatischism]

Are these curves automatically made by audissey or have you created these to suit your preferences?
I am asking because the compensation on the highs is much smaller than the one you obtain by subtracting ISO curves like @dasdoing has suggested

They are built in to Audyssey.

 

[dasdoing]

for music I would set the loud level per ear. put it at a level where the music sounds best. a loud level you would use while givig a party. from there aply the correction curve that gives you desired level

After a year or so using compensation, I came to the conclusion the best calibration is using a level you can barely hear and set the level so it sounds balanced. So contrary to what I said above. The reason is that "level where the music sounds best" depends a lot on mood and fresh ears

 

[Petr66]

Plugin has not yet been officialy released so you don't see it in the plugin list but it is fully functional and will soon be released. Installation instructions are on the link I posted.

Here they are:

1. Enable SSH and connect to Volumio
To do that, have a look here : ssh in volumio

2. Download and install the plugin
Type the following commands to download and install plugin:

wget https://github.com/balbuze/volumio-plugins/raw/master/plugins/audio_interface/brutefir3/brutefir.zip
mkdir ./brutefir
miniunzip brutefir.zip -d ./brutefir
cd ./brutefir
volumio plugin install
cd ..
rm -Rf brutefir*

Greetings. Excellent work has already been implemented. This is exactly what I need. I only have one problem:
Can I somehow correct the properties of the curves? This way it probably adds the lower band correctly, but it also adds a lot to the upper band. If I look at the perception curves of the ear at different acoustic pressures, it is clear that the differences are mainly at the lower end of the band, but the differences between the individual curves of the upper band are essentially not. The actual shape of the curve is not important, one is used to it. Assuming that Mastering is done at 85 dB SPL and then all the lower levels of reproduction need to be supported by this feature, this is certainly correct. But from all the known Fc / SPL ear sensitivity curves, it is clear that the difference in the sensitivity curves at 10kHz and 1kHz does not differ significantly depending on the SPL. Conversely, at the lower end of the audible band, the differences between the individual curves are considerable. Of course, I found the VoBAFfilters folder, but I don't know what could be done with the files to avoid such a large amplification of the upper one. I use Studio monitors and the gain at the upper end of the band is quite indirect. In my opinion, low frequency corrections work properly. I consider the correct solution to this issue to be an underestimated basis for domestic reproduction.
Thank you very, very much for your advice. I'm sorry, I'm using a translator ...
Long live audio!
Peter

 

[stevenswall]

I've been listening to a stereo pair of Sonos One speakers... And at low volumes the bass sounds better than the Kali IN-8 v2 pair I have as well as my Genelec 2.1 system unless I really boost the bass.

Curious how Sonos does it as I don't think it's adjusting it for the music, I think they just figure they should make it flat near the limits of the speaker, roll off the bass when it hits limits, and boost it when the volume is turned down.

 

[stevenswall]

A PC with EqualizerAPO can do it. It has a loudness filter. Then you use the Windows Volume Control to engage it's dynamic compensation.
Though I'm not sure how it would work with those USB dacs, whose drivers make the Windows volume slider directly control the dac itself, such as the Dragonflies.
I'm still astonished that MiniDSP hasnt implemented such a feature in their devices. There are lots of threads begging for that in their forums.

Not familiar with Equalizer APO, where is this setting? I swear this should look 10x as complex and show more options. If it's relying on Windows doing some dynamic range compression we may be talking about different things. I'm looking for something to keep bass higher at lower volumes.

 

[Berwhale]

Not familiar with Equalizer APO, where is this setting? I swear this should look 10x as complex and show more options. If it's relying on Windows doing some dynamic range compression we may be talking about different things. I'm looking for something to keep bass higher at lower volumes.



View attachment 270301

 

[Hayabusa]

Not familiar with Equalizer APO, where is this setting? I swear this should look 10x as complex and show more options. If it's relying on Windows doing some dynamic range compression we may be talking about different things. I'm looking for something to keep bass higher at lower volumes.



View attachment 270301

Indeed its something different, this curve only changes with the volume control setting, not the level of the signal itself.

 

[stevenswall]

Indeed its something different, this curve only changes with the volume control setting, not the level of the signal itself.

I just turned it on and it seems to be doing what I was expecting/wanting. Sonos does the same thing with boosted bass at lower levels and it sounds great.