Measuring HRTF for headphone use

[solderdude]

I learn by doing, so reading research papers and recommendations from others is just an incentive for me to do my own experiments
....
I believe I've found a method that works well for me using the in-ear headphones. In the process, I've discovered a few other methods to achieve similar results. From Greisinger to F-M like curve measurements, I now have a much better understanding of what effect each of the FR distortions has on music reproduction.

Exactly this (own experiments) is what is important to understand ones own limits and those of the equipment.

I was never after a single, general HRTF curve or even a single correction that would work on more than one set of headphones or one set of ears.

I stand corrected !

HRTF measurement, specifically, was also part of a much longer term project for me. I'd like to be able to correct for sound directionality based on head position, without spending thousands of dollars on one of the available systems that do head tracking. But this is far off into the future.

This will be the toughest thing to achieve. Do keep us posted should you ever get around to it and get good results.

 

[Shikamon]

Also, does anyone know of a way to get noise bands? The only way I did this was to bring all frequencies down and leave one at 0dB and then play pink noise from REW. :0

 

[solderdude]

He has some of them here: http://www.davidgriesinger.com/headphones.htm

http://www.toon-llc.com/support/obng_en.html

You could make them yourself, most likely, using free audio software like Audacity.

Maybe this site could help: https://www.wavtones.com/functiongenerator.php

 

[Shikamon]

Awesome! I also found a plugin for Audacity called Narrowband Noise. I can make band noises with that too.
https://wiki.audacityteam.org/wiki/Nyquist_Generate_Plugins#Harmonic_Noise

 

[Shikamon]

That or you can generate pink noise in Audacity and use this plug in to band pass filter for each frequency to test with:
https://forum.audacityteam.org/viewtopic.php?p=204507#p204507

 

[solderdude]

Nice find,

I would recommend to 'scrutinize' the FR area between 5kHz and 11kHz by using some noise bands closer together.
Most headphones have nasty peak(s) there that you really want to EQ.

 

[Shikamon]

Hey y'all! I just recently bought some new speakers to help do my equal loudness test. It's a Bluetooth speaker from Anker and they sound really good on it's own. Very portable too. ouob
https://www.amazon.com/gp/aw/d/B01MTB55WH/ref=sspa_mw_detail_0?ie=UTF8&psc=1

 

[Shikamon]

Hey @solderdude, how wide should a pink noise band should be? I'm trying to create some in Audacity and I thought to use a narrow band noise generator plug-in I found on the web. :0

 

[solderdude]

I would say +/- 10% of the frequency.
That's where the -3dB cut-off points will be.
At least, this way the bands used in the video makes sense.

He did upload a few of those frequency bands.
Analyze it and see how that band was made.

use steep filters.

 

[Shikamon]

I did analyze it and it seems he referenced the cut offs like you said and the bandwidth does follow the chart I found here:
https://www.engineeringtoolbox.com/octave-bands-frequency-limits-d_1602.html

 

[solderdude]

Third octave bands is what he uses, but perhaps with octave bandwidths. This ensures some overlap in each band.

 

[pwjazz]

In my opinion one should thus not compensate 'exactly' acc. to measurements (as one compensates to the flaws of the rig which are compensated rather than the actual response) BUT must look at the great picture and apply some 'gentle' and average EQ in the area's which need improvement.

This is interesting to me because I recently went through an effort to fairly exactly compensate for irregularities in my HD58X's frequency response. In particular, it always felt a little grainy to me, and filling in the valley at 6 KHz and cutting the peak at around 8 KHz did in fact seem to smoothen out the sound. I used to dislike listening at higher volumes because it really brought out the grain, but now I can happily crank it up without bother.

Note, these measurements were made on a MiniDSP E.A.R.S. and EQ'ed to their HEQ compensation which fairly closely follows the Harman target.

 

[Shikamon]

@pwjazz Nice! Kinda wished I had the E.A.R.S. product from MiniDSP. Though, I trying to do this without it since I believe doing it by ear may get a fairly accurate response when done carefully.

 

[solderdude]

This is interesting to me because I recently went through an effort to fairly exactly compensate for irregularities in my HD58X's frequency response. In particular, it always felt a little grainy to me, and filling in the valley at 6 KHz and cutting the peak at around 8 KHz did in fact seem to smoothen out the sound. I used to dislike listening at higher volumes because it really brought out the grain, but now I can happily crank it up without bother.

View attachment 16385

Note, these measurements were made on a MiniDSP E.A.R.S. and EQ'ed to their HEQ compensation which fairly closely follows the Harman target.

It is interesting as the mini EARS measured dips at 6kHz and a peak at 8kHz as well as a peak of +8dB at around 17kHz.

I measured the HD58X as follows:

Below Judes measurements on a HATS.

Neither measurements show a dip at 6kHz and peaks at 8kHz and 16kHz.

Marv (SBAF) is trying to achieve a better compensation for the mini EARS.

 

[Shikamon]

Hey @pkane! How's the experiment going? Find any new results with your method of headphone equalization? :0

 

[pkane]

Hey @pkane! How's the experiment going? Find any new results with your method of headphone equalization? :0

Not much new to report. I've been using the in-ear microphones to create a linear response with three different headphones (HE560, HD650 and Stax Lambda), and still like the result, a lot

 

[Shikamon]

Good to hear! I think of trying to either get the in ear mic you purchased or just build them myself. :3

 

[svart-hvitt]

GENELEC AURAL ID

https://auralid.genelec.com/

https://www.genelec.com/aural-id-software

 

[pkane]

GENELEC AURAL ID

https://auralid.genelec.com/

https://www.genelec.com/aural-id-software

Need more details

 

[svart-hvitt]

Need more details

Seems like this was a teaser only. Genelec is science-driven, so it will be nice to see what this. Needless to say, neutrality is Genelec’s aim so this is probably not an «audiophile» oriented solution.