Threads of Binaural virtualization users.

[NotInYourHead]

Yes, I think most of your views are correct.
Here's a simple and concise statement of my position on your points:

When applying EQ for the purpose of HPCF, the goal is for the headphones to disappear. If the room response you're hearing belongs to someone else (or a dummy head), then another EQ will be applied to compensate for the inconsistent response. This can make it sound somewhat plausible, but fundamentally, it's unavoidable because your physical cues aren't the same. You are not another person (or a dummy head).
So, I'll refrain from commenting on the process and results of EQing to match another person (or a dummy head).
There's a difference between trying to make something that doesn't fit, fit, and making something that already fits, fit even better....
But does "not fitting" mean it's wrong? No, it doesn't. It just means it doesn't fit.
If your definition of "the right sound" is how it compares to the way you actually hear, then you should be hearing the right sound without EQ.
Conversely, if you need to add EQ or seek out and add something else, it means the sound doesn't match how you actually hear at all.

Update: After some A/B tests (not blindfolded), I ditched the DF EQ filters entirely, and it sounds much better. Realism is enhanced, and everything sounds less distant and tinny. I believe it's due to DF's tampering with the 4Khz region (there should be a hump in 3-4Khz region due to ear gain) but ASH Toolset has likely already included ear gain into its BRIR output.
All I have to do now is tune the bass and treble levels

 

[Lion♡]

Update: After some A/B tests (not blindfolded), I ditched the DF EQ filters entirely, and it sounds much better. Realism is enhanced, and everything sounds less distant and tinny. I believe it's due to DF's tampering with the 4Khz region (there should be a hump in 3-4Khz region due to ear gain) but ASH Toolset has likely already included ear gain into its BRIR output.
All I have to do now is tune the bass and treble levels

It’s normal to have ear gain. More precisely, it’s the typical binaural room response—including ear gain—multiplied by the response that flattens the IEMs or headphones you’re currently wearing.
But,

So, I'll refrain from commenting on the process and results of EQing to match another person (or a dummy head).

As I said, I have nothing to say about that situation...

If you’ve tweaked it in various ways and you like it, then that’s good for you.

 

[fcserei]

Finally I could convince my wife to scan my head and I've created a medium resolution (~10k triangles) model and simulated my personal HRTF with mesh2hrtf (9h computation time on a M1 Mac)

I have to admit, personalization adds a lot to the binaural experience.

Previously experimented with lots of sofa files from different databases, and what was apparent, that while all more or less can externalize the source, they have wildly different perceived tonalities.

Below the default generic head HRTF simulation and my personal results from the simulation.

Default:

Personal:

Default:

Personal:

The HRTF is used in the SPARTA binauraliser in 5.0 mode with the added ambisonic room simulation. I don't want to simulate speakers in a room like Impulcifier or the Realizer, I want to put the performance in a real space.
The rest is Supperware head tracker, and Yamaha HP1or Sennheiser HD559 headphones, both EQ-d flat at my blocked ear canal. The HRTF is generated flat at the entrance of the ear canal. There is no need for diffuse field EQ, Harman curve or other sorcery, because my personal diffuse field curve is basically the weighted average of my full sphere HRTF. The frontal stereo channel gets the proper HRTF treatment, and the front and rear reflections are created from the ambisonics room simulation, so they are arriving with the correct weight and HRTF through the binauralizer.

So far I have only a limited time to listen, but the results are encouraging. The personal HRTF solidifies the out of head experience compared tho the general HRTFs, but what's more important, it makes the music somehow tonally correct. I don't feel the need fiddling with the EQ so far.
I feel headtracking is still very important to maintain the illusion, without it the experience collapses if you move, but the big change is that the personal HRTF can maintain not only the position of the stage but also no shifts in perceived tonality in case of big head movements. The whole sound is easy and natural being there experience with regular stereo recordings.

Next step: I will try a 40k triangle full resolution simulation...

 

[katamana]

Just curious, to what extent can you simulate speakers using Impulcifer (with Hesuvi)?

I've tried dozens of measurements with Impulcifer, using a standard stereo speaker set (equilateral triangle placement, 1 meter from ear to speaker). The result is amazing, however, I feel the simulation is kind of wider and closer than real speakers., lacking solid image like real speakers but more like the feeling of headphones (I'm using HD800s btw) without simulation (i.e., left signal only exists on left side, making soundstage wider but to some extent, 'fake'). My ears and brain will definitely tell me it's just a simulation and differs from my speakers (and I feel more reverb than real speakers, or the reason may be a bad capture of reflections...). I tried to reduce the early reflections, but doing this will make the sound drier (of course...) and even more like headphones without simulation. Will it perform better if I set the speakers to, for example, 2 meters, or just narrow the distance of the speakers while keeping the listening point the same? My room is a little bit messy and I think I have to move some stuff out to test...

I've also tried other binaural virtualization solutions like APL Virtuoso (with my customized sofa generated by mesh2hrtf), dearVR, Waves NX, etc. Impulcifer performs the best among all methods, as others feel like dragging the center of sound just out of my head and placing it near my nose. I guess the performance of virtualization really depends on early reflections but I wonder if Impulcifer will do much better as I feel mismatch of soundstage/image between the simulation and real speakers currently.

Btw, thank you for adding the virtual bass function, my speakers will roll off from 40hz and I do need more bass after processing by the original procedure.

 

[myHRTF]

The result is amazing, however, I feel the simulation is kind of wider and closer than real speakers., lacking solid image like real speakers but more like the feeling of headphones

There are several possible reasons for that:

• The microphone capsule needs to be inserted deeper inside the ear canal.
• Issues with measurement repeatability, for example caused by the fixture used to keep the capsule inside the ear canal.
• Limitations of the blocked ear HRTF measurement method as pointed out by Griesinger ("convenient untruth").

Will it perform better if I set the speakers to, for example, 2 meters, or just narrow the distance of the speakers while keeping the listening point the same?

I guess it's a more fundamental problem as pointed out above.

 

[katamana]

There are several possible reasons for that:

• The microphone capsule needs to be inserted deeper inside the ear canal.
• Issues with measurement repeatability, for example caused by the fixture used to keep the capsule inside the ear canal.
• Limitations of the blocked ear HRTF measurement method as pointed out by Griesinger ("convenient untruth").

I guess it's a more fundamental problem as pointed out above.

Thanks! I have three binaural mics, sound professional, microphone madness and samson lm10x. sound professional can be placed deeper than microphone madness but performs worse, still wondering if it's because the angle (I attached a small piece of foam earplug but when inserting the capsule it will not be strictly tangent to ear canal). The lm10x doesn't work very well in my ears as I find it hard to place (and fix) it in ear canal. I'll try more tests and hope i can find some improvements.

 

[myHRTF]

I took a look at the microphones that you have listed: lm10x is far too big to put inside the ear canal. The sound professionals mics also look too big for the job but I might be wrong on this. The microphone madness mic is suitable in terms of size.

Philipp

 

[Curvature]

The most complex part of this is capturing a personal HRTF. I am looking into trying @fcserei's method.

I took a look at the microphones that you have listed: lm10x is far too big to put inside the ear canal. The sound professionals mics also look too big for the job but I might be wrong on this. The microphone madness mic is suitable in terms of size.

Philipp

I don't know of any accessible ear canal microphones. Do you? I have the SP mics as well. They sit inside the concha, just behind the tragus.

 

[katamana]

I took a look at the microphones that you have listed: lm10x is far too big to put inside the ear canal. The sound professionals mics also look too big for the job but I might be wrong on this. The microphone madness mic is suitable in terms of size.

Philipp

Hi! Sorry for not specifying clearly. Actually the lm10x may be the smallest among what I listed. It's only 3mm size and other two mics are both 6mm. The problem of lm10x is the cable is too hard and I find it difficult to place in my ear canal (since it's not designed as a binaural mic but lavalier microphone). For the sound professionals I use ms-tfb-2, and cut the entire silicone hooks/shell so it can be placed within ear canal rather than just outside of opening. Microphone madness ms-bs-8 works well in stability as it comes with a nice foam earplug, however this also stops it being placed at a deeper position in ear canal (should be right at the ear canal opening)

 

[fcserei]

For ear canal mic i use a modified Dayton iMM6. Removed the capsule from the endpiece, extended the wire and put the capsule in a fitting IEM earplug.
It comes with calibration and i made a couple of measurement, and it seems it retains the FR quite well in free field compared to the original setup.
Tried to use it for the HRTF measurements but the room is too noisy, too much room interaction even though I measure < .3 s RT60, and to make a full sphere measurement I need a serious geometry setup.

I will try to use it for validate the simulated hrtf with measured ones in some specific directions.

What is the mic perfect for is headphone correction measurements. It helped me to understand why I like the Yamaha HP1 for binaural. It takes eq very well, distortion is low and very low sensitivity for repositioning both the mic and the headphone.