Surround Virtualization for Headphones

[jagxjr15]

I've found a gizmo from EPOS | Sennheiser has made me very happy with rendering 7.1 through stereo headphones: their GSX 1000 Audio Amplifier. This thing's intended for gamers, so there's an intercom channel that's easy to ignore. On the Mac you do need to delve into Audio/MIDI Setup to get the Mac to understand it takes multichannel on first use; after that, it needs no special prep.

No doubt the Smyth A16 Realizer is far superior, but I get full surround (including rear channels) that's entirely satisfactory for casual listening or movie viewing from the GSX 1000. Evidently it's got a Cyber Monday deal going for it today... $189.00

https://www.amazon.com/dp/B01LDTP484/ref=cm_sw_em_r_mt_dp_YVZGJRR0VZW59PATJ7E5

Sure, it's running on some population-averaged HRTF. That having been said, it works well for my friends and I. My expectation is that there will be a lot of more sophisticated devices at lower price points joining the A16 in the next year.

Bob

Thanks for the low-cost tip.

 

[Soundfield]

Well, it works for the vast majority of people. It didn't work for me either, until I closed my eyes while listening. Also, it may depend on the choice of headphones: the Stereophile review of the AKG 1000 headphones said that they produced the binaural effect for people who didn't get it from any other headphones.

I must have tried dozens and dozens of different types of headphones over the years. None of them have ever done anything to solve the very unrealistic 'in-the-head' imaging I get with ordinary stereo (let alone binaural), and which I find particularly unpleasant.

 

[jagxjr15]

I must have tried dozens and dozens of different types of headphones over the years. None of them have ever done anything to solve the very unrealistic 'in-the-head' imaging I get with ordinary stereo (let alone binaural), and which I find particularly unpleasant.

The AKG K1000s might work for you. They are unlike all other headphones, to my knowledge, in that they do not touch your ears, which is why AKG calls them 'ear speakers' rather than headphones.
The 'ear speakers' sit in a metal frame which goes over your head, and the 'ear speakers' swivel about so the angle of the speaker units with respect to your ears/head can be adjusted. I had no problems wearing them for hours at a time. Since they are more like loudspeakers than headphone transducers, they have to be driven by a speaker amp; they will not work if you try to drive them with the output of a headphone jack; but the ideal solution is to drive them with the matching AKG K1000 amp.

 

[stevendive]

Try closing your eyes when listening. Binaural only works for me if I close my eyes while listening -- and it's night and day -- eyes open, stereo only -- eyes closed, the full 360 immersive binaural effect! Also, it may depend on the choice of headphones: the Stereophile review of the AKG 1000 headphones said that they produced the binaural effect for people who didn't get it from any other headphones.

I've tried all sorts, just to try to cancel visual domination effects. Nothing's worked at all well so far. The closest to working for me at all has been ambisonic binaural, which may work better with head tracking if I ever get to try this.

My original question was really the other way around. For binaural with visual reinforcement, as happens with VR + headsets with ambisonic audio (3rd or greater order ambisonics), hearing might be trained to perceive good surround including elevation.

 

[jagxjr15]

I've tried all sorts, just to try to cancel visual domination effects. Nothing's worked at all well so far. The closest to working for me at all has been ambisonic binaural, which may work better with head tracking if I ever get to try this.

My original question was really the other way around. For binaural with visual reinforcement, as happens with VR + headsets with ambisonic audio (3rd or greater order ambisonics), hearing might be trained to perceive good surround including elevation.

Right. I have never tried binaural with video. I don't know of any films with binaural soundtracks, come to think of it. The Kraftwerk: 3D The Catalogue Box has a disc with a "Headphone Surround 3D mix", but I haven't gotten around to listening to/viewing that one yet. I can tell you that if you are watching a movie, the Smyth A8 imaging, when it works, does not change or collapse if you close your eyes.

But I was surprised that my small stack of (audio only) binaural discs only imaged properly with eyes closed, with the AKG K1000 system. I doubt that the AKG would work with the Smyth, but I've never tried them together. With the Smyth I only used the Stax headphones supplied with the Smyth, and lately with the Sennheiser 800S cans.

The human brain/sensorium is very good at adapting to the environment to compensate for changes, but whether and how much (and how) visual cues affect audio perception is a hard problem. Floyd Toole's book on speakers in small rooms treats some of the issues.

 

[doity]

I have virtually no experience with the newer Surround headphones as all of my listening is done on old school analog equipment. Obviously most should/would work on such systems as a headphone jack is a headphone jack right? No? Anyway the point is moot as I don’t have the $ to invest in a costly toy like a Smyth system......though I wouldn’t mind being able to.

I do own a pair of the Koss Phase 2+2 four channel headphones and they work remarkably well, and no need for a computer or a screen to operate them. The Koss phones do a fantastic job of surround without having to do a brain scan before using them. The only problem is that sometimes it is hard to differentiate between front and back, even if it is a very ‘discrete’ listening experience. Meaning that I can definitely hear the separation of instruments and vocals. It just is more of an encompassing listening experience and not as life-like as you probably get with newer technology.

How do the TOTL Smyth headphones sound in comparison to an actual 4 or 5.1 “real life” listening experience?

 

[jagxjr15]

I have virtually no experience with the newer Surround headphones as all of my listening is done on old school analog equipment. Obviously most should/would work on such systems as a headphone jack is a headphone jack right? No? Anyway the point is moot as I don’t have the $ to invest in a costly toy like a Smyth system......though I wouldn’t mind being able to.

I do own a pair of the Koss Phase 2+2 four channel headphones and they work remarkably well, and no need for a computer or a screen to operate them. The Koss phones do a fantastic job of surround without having to do a brain scan before using them. The only problem is that sometimes it is hard to differentiate between front and back, even if it is a very ‘discrete’ listening experience. Meaning that I can definitely hear the separation of instruments and vocals. It just is more of an encompassing listening experience and not as life-like as you probably get with newer technology.

How do the TOTL Smyth headphones sound in comparison to an actual 4 or 5.1 “real life” listening experience?

Back when I using the Smyth A8 with the Stax headphones I was running the signal through the Trinnov processing in a Sherwood R-972 receiver and when it all worked it was really great, the best thing I had ever heard, but the Sherwood was a mess and when it finally died, the fun was over. The R-972 was the flakiest thing I ever had and it was hell to set up. I will never use another one. At that time I was a daily follower of an R-972 user thread and it wasn't just my unit: EVERYBODY had trouble with it. Outlaw Audio had announced that their next receiver was going to have Trinnov, but they eventually gave up on it, seeing how much trouble the R-972 was. That and the flaky nature of the A8 were too much for me. I have been chasing the dragon ever since.... Maybe this will be the year it all works. I also like 3D TV and I have a 2K+ Cinera setup for that -- but first I have to get the audio side to work.

 

[Quadkid]

Anyone have experience with Apple Airpod Max in this regard?

 

[mkt]

This DAW plugin uses measurements (video based) of your ears and torso to compute a head-related transfer function or something that works with stereo, surround or immersive.
https://www.genelec.com/aural-id

 

[zeerround]

490 € / yearly. Not sure why you need to keep paying once you have your hrtf?

I haven't watched the video yet, however.

Interesting that this is from a speaker company.

 

[MidiMagic]

I have virtually no experience with the newer Surround headphones as all of my listening is done on old school analog equipment. Obviously most should/would work on such systems as a headphone jack is a headphone jack right? No? Anyway the point is moot as I don’t have the $ to invest in a costly toy like a Smyth system......though I wouldn’t mind being able to.

I do own a pair of the Koss Phase 2+2 four channel headphones and they work remarkably well, and no need for a computer or a screen to operate them. The Koss phones do a fantastic job of surround without having to do a brain scan before using them. The only problem is that sometimes it is hard to differentiate between front and back, even if it is a very ‘discrete’ listening experience. Meaning that I can definitely hear the separation of instruments and vocals. It just is more of an encompassing listening experience and not as life-like as you probably get with newer technology.

How do the TOTL Smyth headphones sound in comparison to an actual 4 or 5.1 “real life” listening experience?

The EVX-4 encoder and decoder were originally designed to make quadraphonics work with the Koss 2+2 headphones so front and back were clearly distinguished. Only after Feldman and Fixler got it to work with headphones did they try speakers.

Also try it with QS.

 

[par4ken]

I'm kind of on a different planet with this crazy idea but here it is: a head tracker for quadphones, using very simple technology such a compass sensor, accelerometer, and raspberry pi/arduino, no face tracking. The head tracker would control the channel output rotation, could be just a servo on the mouse tracking pad with the clicker taped down lol. It wouldn't be hard for someone with good programming skills(not me), would be very ugly and only work for side-to-side panning of course, I like looking like an escaped science project anyway.
I'm also looking for a set of the Koss quadphones with the special control box, something like that, a circuit that controls balance/blend/phase, or circuit like the pre-synth idea @Sonik Wiz has talked about for using with the SM(I cant find the specific thread) could also be interesting through quadphones, attached to a servo controlled by the head tracker. Need octo-phones! 🎚🕹

The Koss (Phase 2+2) phones are rather cool with the control box. Flipping the switches alters the sound field, sounding different with the flipping of each switch but it's not necessarily natural sounding. If you find a pair be prepared to replace the foam surrounds as they will most certainly be rotted. Sonics Pre-Synth was intended more for use with a decoder but would work well through phones to expand the sound field. I would also suggest my decoder circuit from, the Akai SS-1 thread, or even the Akai unit itself. With that you can add (a variable amount) of out phase blend to the back channels and in phase blend to the front.

Scott (Sonic) also developed a software pre-synth method that also works well. Perhaps Scott can find the link to the Pre-Synth threads. I'll look for the MCS Review article myself and post a scan here if it can't be otherwise located.

 

[par4ken]

The EVX-4 encoder and decoder were originally designed to make quadraphonics work with the Koss 2+2 headphones so front and back were clearly distinguished. Only after Feldman and Fixler got it to work with headphones did they try speakers.

Also try it with QS.

The Fixler Effect!

 

[Sonik Wiz]

The Koss (Phase 2+2) phones are rather cool with the control box. Flipping the switches alters the sound field, sounding different with the flipping of each switch but it's not necessarily natural sounding. If you find a pair be prepared to replace the foam surrounds as they will most certainly be rotted. Sonics Pre-Synth was intended more for use with a decoder but would work well through phones to expand the sound field. I would also suggest my decoder circuit from, the Akai SS-1 thread, or even the Akai unit itself. With that you can add (a variable amount) of out phase blend to the back channels and in phase blend to the front.

Scott (Sonic) also developed a software pre-synth method that also works well. Perhaps Scott can find the link to the Pre-Synth threads. I'll look for the MCS Review article myself and post a scan here if it can't be otherwise located.

Ya got a good memory Mr. Parsons!

https://www.quadraphonicquad.com/forums/threads/stereo-pre-synthesis.25299/
What I would like to add to this is it isn't a process you must simply do, it is something that can be played with real time to see what works best. By this I mean you can use the effect Preview function in AA3 & fiddle with the settings back and forth & evaluate. Works with headphones or fed to a decoder for speaker listening. And for speakers if you have a wireless keyboard/mouse you can sit in the sweet spot & pre-synth to perfection.

Shout out to @MidiMagic , Adobe Audition works great with Win XP > Win 10.

I must say again, if you think stereo sounds good through a Surround Master wait till you play with this!

 

[Soundfield]

The Fixler Effect!

That review damned with faint praise didn’t it? :

“Some of our test listeners confirmed that they heard sound that seemed to come from all around them-as in
loudspeaker listening. Some found that they could hear sounds at the back but that front -centered soloists, for example,
emerged toward the top of the head, rather than at the front. Others had a little difficulty with back -center sounds as well. The consensus was, however, that the imaging was superior to that from any quadriphonic headphone we have tried so far, though not always equal to that with loudspeakers. Certain sounds (in the original Chase record, for example) that are supposed to fly in a circle around the room, while fairly convincing in loudspeaker listening, proved difficult to image as a full circle via the headphones.”

I get the impression the reviewer really just wanted to say ‘no quad headphones work very well but these Fixler phones are slightly less bad than the others’!

 

[par4ken]

That review damned with faint praise didn’t it? :

“Some of our test listeners confirmed that they heard sound that seemed to come from all around them-as in
loudspeaker listening. Some found that they could hear sounds at the back but that front -centered soloists, for example,
emerged toward the top of the head, rather than at the front. Others had a little difficulty with back -center sounds as well. The consensus was, however, that the imaging was superior to that from any quadriphonic headphone we have tried so far, though not always equal to that with loudspeakers. Certain sounds (in the original Chase record, for example) that are supposed to fly in a circle around the room, while fairly convincing in loudspeaker listening, proved difficult to image as a full circle via the headphones.”

I get the impression the reviewer really just wanted to say ‘no quad headphones work very well but these Fixler phones are slightly less bad than the others’!

True that phones (stereo or quad) can't image the same (or as well) as speakers can. Still the sound of quad phones can be rather amazing, much beyond that of regular stereo phones. Phase is very audible through phones and can create a great sense of space. The Fixler effect is intended to work on stereo sources, look at the control box only one input plug. Talk of listening to Chase via a matrix decoder with the sound panning around is a bit of a red herring, you will never hear sounds panned around you the same as you do with speakers. I suspect that the author was speaking to the uninitiated that might have greater initial expectations of what quad phones can do and to the skeptics that think that the whole idea is a bit ridiculous. I never got the impression that Fixler effect phones were simply just less bad than other quad phones.

I never understood why Koss placed their drivers vertically rather than horizontally in their phones (with the exception of the Phase 2+2). But even with those regular Koss phones discrete quad does still sound better than regular stereo does, it's fuller, richer sounding. Full logic SQ Matrix quad is not very good with headphones, and Tate only slightly better. Much better to use a basic L-R, L+R design as I described, same idea as Fixler. Matrix quad SQ or QS without any form of logic can sound good as well, via phones, due to the varied phase relationships.

Sad that nobody ever came out with quadraphonic electrostatic phones. Electrostatics are so much more detailed sounding than regular phones are!

 

[MidiMagic]

Shout out to @MidiMagic , Adobe Audition works great with Win XP > Win 10.

I have too many custom processing templates to ever change to other software. I created some special ones for surround sound. They won't work on other software.

 

[jaybird100]

That review damned with faint praise didn’t it? :

“Some of our test listeners confirmed that they heard sound that seemed to come from all around them-as in
loudspeaker listening. Some found that they could hear sounds at the back but that front -centered soloists, for example,
emerged toward the top of the head, rather than at the front. Others had a little difficulty with back -center sounds as well. The consensus was, however, that the imaging was superior to that from any quadriphonic headphone we have tried so far, though not always equal to that with loudspeakers. Certain sounds (in the original Chase record, for example) that are supposed to fly in a circle around the room, while fairly convincing in loudspeaker listening, proved difficult to image as a full circle via the headphones.”

I get the impression the reviewer really just wanted to say ‘no quad headphones work very well but these Fixler phones are slightly less bad than the others’!

The EVX-4 encoder and decoder were originally designed to make quadraphonics work with the Koss 2+2 headphones so front and back were clearly distinguished. Only after Feldman and Fixler got it to work with headphones did they try speakers.

Also try it with QS.

I never saw anything that said the EVX-44 was intended for use with headphones, Koss or otherwise. I had the K2+2 phones and was disappointed in them. I never got a real sense of front-back separation from them even with discrete material. The EVX-44 was marketed as a "universal" decoder that could mutually decode their own system, SQ, or any other matrix. Thing is, it's parameters were set somewhere in between, so it really couldn't decode any available matrix system accurately. It could be used to "decode" stereo records,but that's about it.

 

[par4ken]

I never saw anything that said the EVX-44 was intended for use with headphones, Koss or otherwise. I had the K2+2 phones and was disappointed in them. I never got a real sense of front-back separation from them even with discrete material. The EVX-44 was marketed as a "universal" decoder that could mutually decode their own system, SQ, or any other matrix. Thing is, it's parameters were set somewhere in between, so it really couldn't decode any available matrix system accurately. It could be used to "decode" stereo records,but that's about it.

The idea of EV-4 (not EV-44) came from Jon Fixler's work with headphones. That decoder box he designed for the headphones is actually an adjustable Dyna quad style decoder. I agree that phones can't place sounds all around like you can with speakers but they can still sound rather nice, creating a larger sense of spaciousness than with regular stereo.

 

[zeerround]

The OP premise of this thread is that headphones CAN and do place sounds outside your head around you, as demonstrated in modern VR systems, at least 4 pro products aimed at producers of immersive audio, and the software included in this thread.

Again, when done right with head tracking and quality phones, you can't actually tell (other than the presence of the headphones on your head) that the speakers aren't on.

Today we have the processing power to accurately model the speaker, room, headphone, and personal ear, head and shoulder models, head position, in real time and deliver the proper signal via headphones to simulate sound coming from speakers/all directions.

The software in this thread, doesn't use headtracking, a major component, but it can get the sound out of your head and present a convincing 3d sound field with your head held still, ASSUMING your ears and head are a good match for one of the included models.

If not, there are instructions for measuring your own here:

https://www.head-fi.org/threads/recording-impulse-responses-for-speaker-virtualization.890719/​

and a real-time tool for encoding music, impulcifer (can also be used for eq/room/headphone correction, etc.).

https://github.com/jaakkopasanen/Impulcifer​

The scripts I have included here, are for pre encoding music, for playback via headphones without iimpulcifer. You can, of course, go either way. I was going with the pre-encoding approach because it wasn't clear to me how to go beyond 8 channels with impulcifer and I wanted to target 7.1.4 or even 7.1.4.4 etc.

Yes this wasn't possible in the '70s, and is only in last few years that I have heard it convincingly, but it is here now.

Again my goal is not QUAD reproduction, but a complete 3D immersive sound field with sounds coming above (and even below) the horizontal plane.

This is all part of an ecosystem for immersive music, including immersive up-remix.