[Dynamo5561]

Hi guys!

I lately discovere the Neutralizer app for Android (https://play.google.com/store/apps/details?id=eu.javeo.android.neutralizer). I find the concept very good and had very nice results with my KSE1500. It basically generates tones in different frequencies (125hz, 250hz, 2khz and so on) and you adjust the EQ until you barely hear the tone. By that you get an EQ profile based on your actual hearing (headphone + own hearing capabilites).

But I find the app lacking more frequencies as IEMs can have adventurous FRs, especially in the highs. Therefore I wanted to replicate that idea on my PC by using a simple tone generator like this (https://www.szynalski.com/tone-generator/) and Equalizer APO. Then playing a tone e.g. 2000KHZ and adjusting it via Equalizer APO so that I can barely hear it. I would then repeat that for the frequencies I would like to.

That was the idea, but I end up having huge differences in volume for different tones, e.g. I need 15DB+ for 20hz while 4KHZ is at 0. So I assume the tones should not have the same loudness for this purpose? Is there a formula how I can calcualte how loud each tone needs to have for this purpose? Or am I doing something completely wrong?

Any help would be appreciated!

 

[castleofargh]

I imagine the app takes your settings and then applies some compensation based on equal loudness curves

What you do when EQing for just audible levels is create an EQ similar to the (threshold) lines on the graph. For example, your ear canal resonance will boost the gain around 3kHz, so you can still hear it when it's quieter than other frequencies, and that's why those graphs show consistently lower amplitudes in that frequency range.
But in real life, sounds are what they are and your ears still boost the 3kHz range. The result with the boost is what you have learned to know as neutral. That's why something tuned to follow your equal loudness contour does not sound neutral. It might not be super intuitive but it's a fact.
You already have your result from trying to create an EQ that follows your equal loudness contour(the EQ from test tones being barely audible), this now need another EQ with the lowest red curve reversed(the biggest boost being near 3kHz, while the subs are going to be attenuated a lot). That should sound fairly neutral to you.

At least that's the hope. Because that curve was created by averaging the results from several listeners. Your own actual 'threshold' curve could show some variations(more so if you have hearing loss). Anyway, the general idea should be something like that for the app. Create the lower curve by hand with EQ and tones, then apply the reverse red curve and hope for a neutral sounding EQ.



edit for reason of amazing typing skills.

 

[Dynamo5561]

Thank you very very much for the explanation . Makes sense to me.

I got the data for the 80phon equal loudness curve (I normally listen around 70db) and took the data points that I want to use. I then calculated the DB difference to the loudest data point in order to generate test tones here: https://www.audiocheck.net/audiofrequencysignalgenerator_sinetone.php (starts from 0 downwards)

80 Phon
FR	DB loudness curve	Relative DB to 50HZ for test tones
50​	101,72​	0​
100​	92,48​	-8​
250​	84,31​	-16​
500​	80,86​	-20​
1000​	80,01​	-21​
1600​	83,74​	-17​
2000​	80,59​	-20​
4000​	78,31​	-22​
6300​	86,81​	-14​
8000​	91,41​	-9​
10000​	91,74​	-9​

Got the files:

My assumption was that based on these tones I can just use EQ to adjust all tones so that I can barely hear them and I should be good to go. The result was definitely in the right direction, but still noticable off, especially the bass. Am I missing something else?

 

[Dynamo5561]

Ah I probably need to take the bottom red curve as you said because that's what I am EQing against. Will try that.

 

[Dynamo5561]

Can confirm, it worked out perfectly!! Thanks again!

 

[castleofargh]

Glad it helped.

 

[peterclau]

Can confirm, it worked out perfectly!! Thanks again!

bruhhh... can u help me in anyway?!

loudness curve, the redline... I am pretty ignorant about audio engineering and stuff...

make a video tutorial (that would be GODLY MUAHUMAUHA)

Neutralizer is the best thing that happened in my L I F E (after being sucked off by a travestite, and enjoying a night of Metallica sepultura and pantera cover at some bar downton).

I am using Neutralizer with my moto g5 speakers (is this a joke?! I Know, right?!)

my amp ml 20

and sometimes my earphones szn pro

and I am amazed. F L A B B E R G A S T E D of how much detail I can get.

So I had the same idea... use tone generator and a equaliser.

but i don't understand what u have done really.

help me pleaseeeeeeeee.

 

[Dynamo5561]

bruhhh... can u help me in anyway?!

loudness curve, the redline... I am pretty ignorant about audio engineering and stuff...

make a video tutorial (that would be GODLY MUAHUMAUHA)

Neutralizer is the best thing that happened in my L I F E (after being sucked off by a travestite, and enjoying a night of Metallica sepultura and pantera cover at some bar downton).

I am using Neutralizer with my moto g5 speakers (is this a joke?! I Know, right?!)

my amp ml 20

and sometimes my earphones szn pro

and I am amazed. F L A B B E R G A S T E D of how much detail I can get.

So I had the same idea... use tone generator and a equaliser.

but i don't understand what u have done really.

help me pleaseeeeeeeee.

It works the following:

You first need to know at what db level you want to do the matching. I usually listen at 70-75DB.

Then you need to search for the corresponding loudness level in the fletcher-munson curve. You can find the data in the internet, e.g. http://www.macfreek.nl/memory/File:Equal-loudness_contours.xlsx

frequency	63 Hz​	125 Hz​	250 Hz​	500 Hz​	1.000 Hz​	2.000 Hz​	4.000 Hz​	8.000 Hz​	11.300 Hz​	16.000 Hz​
80 phon​	88,0 dB (SPL)​	85,9 dB (SPL)​	84,3 dB (SPL)​	83,5 dB (SPL)​	80,0 dB (SPL)​	78,3 dB (SPL)​	76,7 dB (SPL)​	76,8 dB (SPL)​	76,0 dB (SPL)​	81,4 dB (SPL)​

What I did now: Take the point that is the loudest and set it as your 0DB, that is important for the tone generator later:

frequency	80 phon	Deviation from loudest point (88DB@64HZ)
63 Hz	88​	0​
125 Hz	85,9​	2,1​
250 Hz	84,3​	3,7​
500 Hz	83,5​	4,5​
1.000 Hz	80​	8​
2.000 Hz	78,3​	9,7​
4.000 Hz	76,7​	11,3​
8.000 Hz	76,8​	11,2​
11.300 Hz	76​	12​
16.000 Hz	81,4​	6,6​

Then you go to a tone generator, e.g. https://www.audiocheck.net/audiofrequencysignalgenerator_sinetone.php

and create test tones based on the data. E.g. @1000HZ we have -8DB

When you have generated all tones, you start playing the loudest tone (in this case 63HZ) and adjust the EQ at 63HZ (use Equalizer APO ideally) until you barely barely hear it and repeat that for every frequency.

You can also use an excel file that you can import into Equalizer APO with the EQ data.

63​	0​
125​	0​
250​	0​
500​	0​
1000​	0​
2000​	0​
4000​	0​
8000​	0​
11300​	0​
16000​	0​

I would also interpolate some data between 2-10KHZ as there is mostly lot going on.