Equal Loudness Fader

[selig]

Hi again, I'm back with an experimental device that uses ColoringEQ and Gain to create an equal loudness fader.



The idea is to use a basic equal loudness curve (in this case based on "Grey Noise") to compensate for volume changes, to explore what that sounds like. The attached Combinator keeps a consistent peak level within a dB or so as the volume is lowered, while also increasingly adjusting the overall EQ curve to compensate for the volume change.
At the top position, there is no difference/no EQ applied. If you play white noise through it, it will be flat in both settings at this point. But as you lower the fader, you hear more of a difference when bypassing the EQ curve.
Interestingly, it's not that obvious when fading out with the EQ curve engaged, it's only when you bypass when the fader is at the half way position or so that you can really tell what's going on.

I will likely explore this device and the concepts behind it on the next live stream, may even try to build a mix using these faders instead of 'normal' faders just to see what happens.

Here's the link to the download:
https://www.dropbox.com/s/lqw8mi9d2z5vk ... b.zip?dl=0

[moofi]

Looks interesting, though I don´t have ColoringEQ Then how does it work, like on what freqruencies?

Edit: without looking at Coloring EQ, I at least assume it´s the EQ Curve you set it to and compensates within ColoringEQ itself?

[selig]

Looks interesting, though I don´t have ColoringEQ Then how does it work, like on what freqruencies?

Edit: without looking at Coloring EQ, I at least assume it´s the EQ Curve you set it to and compensates within ColoringEQ itself?

It basically takes a ‘grey noise’ curve and applies it gradually as you reduce the fader, but keeping the same overall level along the way. So no matter which ‘mode’ you select, the level is consistent even while the spectrum changes drastically.
https://en.wikipedia.org/wiki/Grey_noise

[avasopht]

This is brilliant!

Kudos

[moofi]

I see, then could you elaborate please how the appliance of the grey noise works?

Looks interesting, though I don´t have ColoringEQ Then how does it work, like on what freqruencies?

Edit: without looking at Coloring EQ, I at least assume it´s the EQ Curve you set it to and compensates within ColoringEQ itself?

It basically takes a ‘grey noise’ curve and applies it gradually as you reduce the fader, but keeping the same overall level along the way. So no matter which ‘mode’ you select, the level is consistent even while the spectrum changes drastically.
https://en.wikipedia.org/wiki/Grey_noise

[motuscott]

Fascinating concept. A mix with this would be very interesting indeed.
I have neither Reason 12 nor Coloring EQ, but I'll definitely check the live stream.

[challism]

Thanks for sharing this with us.

[selig]

I see, then could you elaborate please how the appliance of the grey noise works?

Grey noise is just white noise with a filter, which represents the equal loudness curve (first defined by Fletcher/Munson).
The idea is that it compensates for changes to how we perceive spectral balances at different playback levels. The biggest difference is that at lower levels we perceive the lowest frequencies as softer than the higher frequencies (especially the upper midrange frequencies).
One could argue that this actually works well in mixing, since when we turn a track way down in the mix it ‘automatically’ sounds ‘smaller’ (less perceived low frequency energy) in addition to being literally ‘softer’. Which got me wondering “what if it DIDN’T” sound smaller?
So I created the fader carefully measuring the results to align with the standard grey noise spec while also keeping the same overall energy level at any fader setting. Assuming a white noise input, the EL (equal loudness) fader measures the same amount of change as a ‘regular’ fader . Meaning, -10 dB on the fader reduces the level by 10 dB in both cases, but the EL version is lowering the mid range frequency by a higher value and the lower frequencies by a lower value (to compensate) in order to keep the overall level the same.
Obviously, for sources other than white noise, you won’t get the same response with both faders, but that’s the point.

So the question that occurred to me was “what would a mix sound like that used these faders instead of regular faders? For this to work, you would have to use a consistent peak level on all tracks (as I already do) because you want all mixer channels to be at the same level when all faders are at the same level, so that fader changes (rather than input trim or inserts) control the final level of each track in the mix. Otherwise, if you adjust gain in other places the EL faders won’t reflect the level changes and thus you won’t hear any difference
Hopefully this all makes sense, and I really have no idea what the results would be if even noticeable. But I’m curious, as always, so will post results here once I get a chance to fully explore this!

[moofi]

Yes, thank you for the explanation (read the link to grey noise already), then the question was more like how do you technically apply the greýnoise?
.

I see, then could you elaborate please how the appliance of the grey noise works?

Grey noise is just white noise with a filter, which represents the equal loudness curve (first defined by Fletcher/Munson).
The idea is that it compensates for changes to how we perceive spectral balances at different playback levels. The biggest difference is that at lower levels we perceive the lowest frequencies as softer than the higher frequencies (especially the upper midrange frequencies).
One could argue that this actually works well in mixing, since when we turn a track way down in the mix it ‘automatically’ sounds ‘smaller’ (less perceived low frequency energy) in addition to being literally ‘softer’. Which got me wondering “what if it DIDN’T” sound smaller?
So I created the fader carefully measuring the results to align with the standard grey noise spec while also keeping the same overall energy level at any fader setting. Assuming a white noise input, the EL (equal loudness) fader measures the same amount of change as a ‘regular’ fader . Meaning, -10 dB on the fader reduces the level by 10 dB in both cases, but the EL version is lowering the mid range frequency by a higher value and the lower frequencies by a lower value (to compensate) in order to keep the overall level the same.
Obviously, for sources other than white noise, you won’t get the same response with both faders, but that’s the point.

So the question that occurred to me was “what would a mix sound like that used these faders instead of regular faders? For this to work, you would have to use a consistent peak level on all tracks (as I already do) because you want all mixer channels to be at the same level when all faders are at the same level, so that fader changes (rather than input trim or inserts) control the final level of each track in the mix. Otherwise, if you adjust gain in other places the EL faders won’t reflect the level changes and thus you won’t hear any difference
Hopefully this all makes sense, and I really have no idea what the results would be if even noticeable. But I’m curious, as always, so will post results here once I get a chance to fully explore this!

[selig]

Yes, thank you for the explanation (read the link to grey noise already), then the question was more like how do you technically apply the grey noise?

OK, I see I left that part out! Sorry about that, here's what I did step by step.
First I construct the grey noise curve, initially from reading charts to see the general amount of reduction at the extremes, as well as the frequency ranges where this occurs.
Next I found an audio file of properly generated grey noise, and used the ColoringEQ spectrum HOLD function to freeze the curve on the display. Then I was able to fine tune the EQ curve to match the grey noise "sample" (one of the main reasons I added a HOLD function on the spectrum display, can't believe all EQs don't allow this!).
Then I listened to both the original grey noise sample, and my version and went back and forth until I couldn't hear ANY difference.
From there it is a simple process to assign a Combinator fader to the Master Gain parameter, which allows adjusting the overall 'depth' of the current EQ curve (also a VERY handy feature I can't believe all EQs don't implement, which functions exactly like a dry/wet control but with no phase interaction). The fader function (with regard to the Master Gain parameter) is inverted such that at the TOP of the fader there is no effect, and the EQ curve/grey noise is gradually introduced as the fader is pulled down, hitting 100% Master Gain at the bottom.
From there I added a Selig Gain, and assigned that same fader to also control the "VCA Mode" fader for the actual level control.
Finally, I needed to make sure the overall level was consistent (it was not consistent initially). Meaning, with the fader at -12 dBFS for white noise, I needed to make sure the grey noise was ALSO at -12 dBFS. This was simple to do by assigning the fader to control the master output gain of the ColoringEQ such that as the EQ curve was increased (as the fader is lowered from the top down) the overall level would 'track' the same as with no grey noise filter. This is the key to 'calibrating' the effect, since the idea here is to create a USEFUL fader that behaves predictably. Hopefully that makes sense!

[moofi]

Thanks a lot, got it.

Yes, dialing in an EQ-curve like dry/wet is pretty handy, especially with a graphic EQ.
Regarding the HOLD function I at least assume ColouringEQ translates the shown/received frequency spectrum into an actual EQ curve?

OK, I see I left that part out! Sorry about that, here's what I did step by step.
First I construct the grey noise curve, initially from reading charts to see the general amount of reduction at the extremes, as well as the frequency ranges where this occurs.
Next I found an audio file of properly generated grey noise, and used the ColoringEQ spectrum HOLD function to freeze the curve on the display. Then I was able to fine tune the EQ curve to match the grey noise "sample" (one of the main reasons I added a HOLD function on the spectrum display, can't believe all EQs don't allow this!).
Then I listened to both the original grey noise sample, and my version and went back and forth until I couldn't hear ANY difference.
From there it is a simple process to assign a Combinator fader to the Master Gain parameter, which allows adjusting the overall 'depth' of the current EQ curve (also a VERY handy feature I can't believe all EQs don't implement, which functions exactly like a dry/wet control but with no phase interaction). The fader function (with regard to the Master Gain parameter) is inverted such that at the TOP of the fader there is no effect, and the EQ curve/grey noise is gradually introduced as the fader is pulled down, hitting 100% Master Gain at the bottom.
From there I added a Selig Gain, and assigned that same fader to also control the "VCA Mode" fader for the actual level control.
Finally, I needed to make sure the overall level was consistent (it was not consistent initially). Meaning, with the fader at -12 dBFS for white noise, I needed to make sure the grey noise was ALSO at -12 dBFS. This was simple to do by assigning the fader to control the master output gain of the ColoringEQ such that as the EQ curve was increased (as the fader is lowered from the top down) the overall level would 'track' the same as with no grey noise filter. This is the key to 'calibrating' the effect, since the idea here is to create a USEFUL fader that behaves predictably. Hopefully that makes sense!

[selig]

Thanks a lot, got it.

Yes, dialing in an EQ-curve like dry/wet is pretty handy, especially with a graphic EQ.
Regarding the HOLD function I at least assume ColouringEQ translates the shown/received frequency spectrum into an actual EQ curve?

No, there is no “auto EQ curve drawing” function in ColoringEQ, but it takes only a minute to match the EQ curve to the spectrum response, only possible because of the hold function. Any EQ could do this by adding a hold (or ‘freeze’) function to the spectrum display. That this has been a common function of many spectrum displays forever makes the omission even more odd IMO.

[moofi]

I see, thank you. Seems indeed like a practical feature, like you could aswell mimic other EQ´s responses by sending whitenoise through them and record the outcome, then redrawing it within the EQ.
Btw I remember someone saying you couldn´t create a drawable EQ without issues, yet as a byproduct of watching musicrelated videos, I did see an EQ that could exactly be handled that way. Just currently cannot remember what EQ it was or in what video it appeared.

Thanks a lot, got it.

Yes, dialing in an EQ-curve like dry/wet is pretty handy, especially with a graphic EQ.
Regarding the HOLD function I at least assume ColouringEQ translates the shown/received frequency spectrum into an actual EQ curve?

No, there is no “auto EQ curve drawing” function in ColoringEQ, but it takes only a minute to match the EQ curve to the spectrum response, only possible because of the hold function. Any EQ could do this by adding a hold (or ‘freeze’) function to the spectrum display. That this has been a common function of many spectrum displays forever makes the omission even more odd IMO.