Guide: stereo to binaural conversion for headphone listening

[tony]

Thanks again Satshanti for such a comprehensive guide at some point if I return to headphones will have to come back to this. Did you post this on Headfi?

[satshanti]

Thanks again Satshanti for such a comprehensive guide at some point if I return to headphones will have to come back to this. Did you post this on Headfi?

I posted an early version on HeadFi about 8 years ago, but people weren't interested. The thing is: if you're really used to regular headphone listening, which headfiers tend to be, strong externalising like I suggest will sound over the top.

It's all really about the brain and its capacity to project and adapt itself. I wear glasses since the age of 12. During the course of my life I've had countless changes to the prescriptions. Each time I start using a new set of glasses, my brain needs one or two weeks to adapt to the new gestalt. Slowly it starts becoming less nauseating and fatiguing and after a while the brain manages to create a solid image from the new visual cues.

New ears would have the same effect, and new headphones or a new way of listening to them. My way is closer to natural listening, like listening to the sound stage of speakers or the world around us, but if the brain's already reprogrammed for traditional "stereo" (as opposed to "binaural") headphone listening, my way will sound too diffuse, too loose, too strange, in a way "unnatural".

Another issue might be the what I would call "virtual resolution" of the sound stage with binaural listening. The HRTF spatial cues need much more accuracy than stereo spatial cues, so to attain the same level of realism, one needs a better headphone system. The sound stage is pretty much stretched out from roughly 150 degrees for a traditional speaker setup to a full 360 degrees for a binaural sound stage. This is more space to "unfold" the sound stage registered in the recording, and therefore more prone to hearing disturbances if either the system or the recording is not up to par. It's just very transparent.

So... it needs a little understanding of the principles involved, a relatively high-quality headphone rig, good recordings and above all... some patience if coming from regular headphone listening. Coming directly from speakers, the effect is instantly perceivable and extremely convincing.

Maybe I should post it on HeadFi again. The new Out Of Your Head software seems popular enough, although mostly with gamers and video watchers. It does work with the likes of Foobar and JRiver, but obviously not with any of the minimalist players we like here. It's my impression that the "purists" at HeadFi, who've been listening to headphones "straight-up" for years, are hesitant to change their ways. :-)

[minionas]

Hi,

Thanks!!!

P.S. You've missed the X file in your pack i guess.. Im eager to try it

[satshanti]

P.S. You've missed the X file in your pack i guess.. Im eager to try it

I just checked and it is in fact included in the zip-archive. Please note that it's not actually called file X. I just gave it that name in the post, because I suspect that officially I'm not allowed to distribute this file. One is able to find it online very easily by just googling and downloading it from somewhere, but to make it easier for everyone, I took the risk of just including it. I'll still not specifically name it, but it's a .dll file that is pretty much the abbreviation of Dolby Headphone. It's the key file that creates the HRTF phase shifts that deceive our ears into believing that sounds are coming from the space around us, rather than from in between our ears. I trust that you'll manage now. :-) Good luck and let me know how you like it.

[minionas]

Oops, i had a hard day i guess:) Hope ill find some time in the evening and will try it.

[Sligolad]

I had my first and jaw dropping experience of what is possible with headphones at the weekend at the Munich HiEnd Show.
To be honest I was a complete skeptic that a set of headphones could externalize sound to the levels I heard at the weekend so it was a mind blowing experience that everyone should try.

For reference I am an occasional Head Phone user but very rarely these days, I do like to listen on good gear and I have a set of Grado RS-1s for home use and a set of Shure SE846 buds for travelling.

Anyway after seeing Fran all excited about his demo of the Smyth Research Realiser A16 at the show I had to go around for a demo.
http://www.smyth-research.com/index.html http://www.smyth-research.com/index_standard.html

The system for demo had a 7.1.4 speaker layout and you start with a set of microphones shoved deep in you ears for setup with tones and sweeps from all the speakers. Then a set of Sennheiser HD800s I think were placed over your ears with the microphones still in for some more setup and then you begin listening to some jaw dropping sounds played back through either the headphones or the 7.1.4 system.

The amazing part was that with the tilt sensor on the headphones as soon as you lift them from your ears and tilt forward the sounds from the headphones immediately and seamlessly transfers to the 7.1.4 system with no perceivable change in location, volume, quality or localisation.
It was really freaky and you initially react in thinking it cannot be happening that the headphones are able to deliver exactly what you hear in the room with all the speakers all around on on the ceiling.

It was my first experience of headphones being able to sound like a studio, hall, theater with all the sound appearing to come from a distance way outside your head like normal speakers.
I had already been to a demo of the Athmos and Auro 3D systems which were really impressive driven by 21 speakers and 21Kw of power and the Realiser A16 could replicate all the Athmos and Auro 3D demo samples currently released for promotion with the same amazing surround effects.

I for one will be signing up for the kickstarter when it opens up hopefully soon.
We should start a separate thread for this when it happens but for now I can see where you are coming from Satshanti and it is an area where there is some great activity taking place at the moment.
Cheers, Pearse.

[satshanti]

Thanks for sharing that. I've not had the opportunity to experience the Smyth Realiser, but have heard a lot about it. It is of course a much more costely system, but I agree, it just shows what's possible and that has been my mission for years, make it possible at a price I can afford, in this case for free. :-)

I can retrieve as much detail and perceive a more spacious sound stage from playing these pre-converted files through a high quality player like MQn or wtfplay and a good headphone system than if I would use my speakers. Of course it will never be quite as realistic as the Smyth system, because Dolby Headphone is based on generic HRTF cues, while Smythe measures and then uses personalized ones. So this doesn't work equally well for everyone. For me it works like a dream, mainly because for years now I've not been able to really play through speakers at live volumes whenever I want. Headphones are perfect, because you can reach a live sound level while not disturbing your neighbours or your partner in any way.

Has anyone yet tried the sample files I uploaded? You can play those directly without having to do any fiddling with foobar.

[minionas]

Ive listened to your samples with newest MQN on my diy dac with modded HD650's and i could perfectly hear/feel dimensionality, localization. Material is new to me, so its hard to comment on reality of this. But ill try this with my material as soon as ill find some time.

[satshanti]

Ive listened to your samples with newest MQN on my diy dac with modded HD650's and i could perfectly hear/feel dimensionality, localization. Material is new to me, so its hard to comment on reality of this. But ill try this with my material as soon as ill find some time.

Great! Looking forward to hearing how you fare.

I've selected the samples based on recording quality. It is actually quite simple. If you've got a realistic and deep soundstage with speakers, chances are you'll experience the same with headphones using this system. As I already mentioned, at least for stereo music, the space often gets "stretched" to fill a full 360 degrees, but it does depend on the original recording of course. Some old recordings done with just 2 mikes, as stereo was originally envisioned, just sound excellent. Some modern highly processed recordings sound kind of "flat" on speakers, and will also do so on headphones. The provided samples are a good representation of the various ways sound can get projected into the virtual space around us. Often with classical orchestras or solo piano it's as if sitting in front of it, as in a proper concert hall, but with the sample string quartet for example, it's as if sitting smack in the middle of the musicians, which is different from what we usually experience with speakers. Vocals are often presented at front center, just as with speakers, but with the echoes and reverb spread out through the space around me, including from the back. This is a subtle effect, but adds a certain level of realism.

[satshanti]

It's time for an update. After I changed from MQn to WTFplay as the go-to player for my daily music sessions, I thought it was time to revisit my binaural setup. The quality had improved to such an extent that I felt I could possibly still squeeze some drops out of the setup. I spent a couple of weeks testing my various binaural settings and finally reached an even higher level of definition and spatial imaging. I decided to push everything a bit more to the front, and leave the back channels mainly for ambient information, but also think I really improved the overall fidelity. I think it's a really noticable improvement. I've updated the prepared sample files (16/44 FLAC), which can still be downloaded in the same Dropbox folder:

Binaural Samples

To reiterate, these are already processed and can be listened to without setting anything up. They should work on any system, but of course only a high-end headphone rig will do them full justice.

The new package with the improved Foobar settings included can still be downloaded from Dropbox here.
This time only the binaural conversion settings are included in the Foobar configuration file.
See previous posts for detailed instructions on how to convert any file to a binaural file for headphone listening.

These days I only listen through headphones and with this new setup to me it's just as nice as listening to speakers.