Ambiophonics 3D Stereo - art of retriving hidden 3D info from stereo.
 L to R, Angelo Farina introduces invited panelists Dave Malham, Robin Miller (representing Ambiophonics) and Markus Noisternig at AES2007 Italia, Parma 11/23~25. Mr. Miller's 14-speaker demonstrations of RACE, Choueiri BACCHv1, and full-sphere 3D using RACE were enthusiastically received by more than 40 attendees. Photo: A.Capra |  The "Ambiophonic Team": Anders Torger, Ralph Glasgal, Robin Miller, & Angelo Farina presenting papers and demonstrating at the AES 19th Conference, Schloss Elmau, Germany, June 2001. |  Dr Ralph Glasgal, Auroral Physicist, at Wilkes Station, Antartica in 1957. Photograph taken by U. S. Navy, NFS |
|---|
Your HiFi System deserves more
Your HiFi system’s performance depends heavily on room acoustics and the accuracy of sound reproduction from your two stereo speakers. Ambiophonics tackles both by using digital signal processing (DSP) and two front-facing loudspeakers to enhance stereophonic and 5.1 surround sound reproduction. This method works well for music, movies, and games in home theaters, gaming PCs, workstations, or studio monitoring setups.
You can try Ambiophonics for free by setting it up yourself with a digital audio workstation (DAW), or opt for a commercial product like BACCH. To compare DIY results with a commercial version, check out Chesky’s Edgar the Barber binaural recording.
Tweak 1: Headphone-Like Clarity and Wide Soundstage
The first tweak delivers detailed, clear sound through your loudspeakers, mimicking the experience of headphones. It creates a 180-degree soundstage with just two speakers—provided the recording supports such width—similar to headphone listening. With recordings like Chesky’s Edgar the Barber, it can even place sound behind your head if that spatial information exists. Note that binaural recordings played through headphones typically lack this rear externalization, keeping sound closer to your head. For more on externalization, see the Ambio book.
Tweak 2: Recreating Live Ambience
The second tweak, called the Domestic Concert Hall, uses DSP to shape your room’s response, immersing you in the ambience of a live event. This concept can also enhance formats like Dolby Atmos or Auro-3D. For a sense of what this tweak offers, refer to Listeners’ Impressions.
My Setup
My room features main Sound Lab speakers paired with 26 small speakers. You can hear audio samples on my YouTube channel.
Your HiFi system’s performance is heavily influenced by the acoustics of the room and the accuracy of sound reproduction by the two stereo speakers. Tweaking with Ambiophonics addresses both of these factors. It is a method that employs digital signal processing (DSP) and two loudspeakers directly in front of the listener to improve reproduction of stereophonic and 5.1 surround sound for music, movies, and games in home theaters, gaming PCs, workstations, or studio monitoring applications.
It is free if you are keen to do it yourself with a DAW or buy product such as BACCH. You can compare the sound of DIY with the commercial version in the Chesky's Edgar the barber binaural recording.
​
The first tweak involves reproducing the sound with details and clarity like headphones listening with your loudspeakers. It also reproduces 180 degree sound stage with the two speakers like listening with headphones provided the recordings made to sound with such wide soundstage. It can also reproduce sound going behind your head if such information exists like what you hear when you play Chesky’s Edgar the barber. (note: binaural recordings even with headphones cannot reproduce the rear information and woud still appears closer to your head. Read about externalization which can be found in the Ambio book.
​
The second tweak involves reproducing the ambience using the Domestic Concert Hall where it shapes the room response to transport you to the live event. This concept can be incorporated into other formats like DolbyATMOS or Aura 3D. To understand what you can expect with this tweak or concept, please refer to Listeners’ Impression.
​
This is my room equiped with the main Sound Lab speakers and 26 small speakers. You can listen to audio samples from my Youtube channels.
​
​
​
​
​
​
​
​
​
​
What is Ambiophonics?
Loudspeaker binaural reproduction of two channels from any format addresses a method to reproduce the stereo layer without the inherent interaural error. This technique produces lifelike sound with images floating in space. You’ll hear a wider soundstage and greater clarity from existing stereo media. . ............Read More
A simple way to demonstrate the concept is by using small speakers positioned no more than 20 degrees apart. A partition can be placed between them to block or reduce sound from each speaker reaching the opposite ear. The picture below shows Miller demonstrating how this can be achieved without DSP or electronic hardware. Purist audiophiles may prefer this approach, as they often dislike DSP.
However, this method is considered impractical and requires significant effort. It does, however, clearly prove that the details and soundstage of standard stereo can resemble the 3D or binaural sound experienced with headphones.
Background
Ralph Glasgal established the Ambiphonics Institute in 1990. He developed the R.A.C.E. algorithm to replace the physical barrier method. Other solutions, such as Carver’s Holographic, were confined to the analog domain.
Today, digital solutions like BACCH, Aria3D, and Soundpimp are available in various forms. Unfortunately, the complete guide, which was accessible on the Ambiphonics website until early 2023, was removed after Ralph closed the institute. Ralph turned 92 in 2023 and is no longer active on social media platforms where he once provided free tutorials on how to implement this at no cost.
Contributors
Ralph Glasgal – creator through the Ambiophonics Institute of the name Ambiophonics, and prime mover of its development, progressing from a physical barrier through DSP for crosstalk cancellation and ambience convolution.
​
Robert E. (Robin) Miller III – engineer/pres. of Filmaker Technology who implemented RACE DSP, the Panambiophone, and other Ambiophonics innovations and related demonstration 2D and 3D recordings, scientific papers and website contents. His own version is at http://www.filmaker.com/surround.htm .
​
Angelo Farina – Ambiophonics researcher at the University of Parma, Italy, who used measured inverse impulse responses of speaker pairs using a dummy head to convolve XTC, and of world-renown halls for ambience convolution.
​
Enrico Armelloni – student of Farina at the University of Parma, Italy, whose doctoral thesis was developed while an intern at Filmaker Technology.
​
Edgar Choueiri – Princeton space physicist and XTC developer who used sophisticated band-splitting to minimize any coloration when realizing very high levels of crosstalk cancellation even up to 20dB. It is now called BACCH.
​
David Wareing – early XTC developer who modeled crosstalk cancellation as a single correction impulse based on the speed of sound and the geometry of the average head.
​
Anders Torger – Swedish developer of “AlmusVCU” Ambiovolver software (XTC, ambience convolution, bass management, speaker position timing) running on Linux PCs.
​
“The shoulders of giants” applies, upon which stand those above who have advanced the art termed Ambiophonics. While this list would eclipse this writing, it would include the work of the ISVR, Günther Theile, and the authors of commercial implementations by Carver and Yamaha, etc.
Technical
Papers
(Please contact if the links no longer work)
​
Ambiophonics -- The Synthesis of Concert-Hall Sound Fields in the Home
by Ralph Glasgal, presented to the AES 99th International Convention, New York City, October, 1995.
​
360° Localization via 4.x RACE Processing by Ralph Glasgal, presented to the AES 123rd International Convention, New York City, October, 2007.
​
Comparison of Crosstalk Cancellation Filters
by Angelo Farina, May, 2010 (preamble and postamble by Ralph Glasgal).
​
Surround Ambiophonic Recording and Reproduction
by Ralph Glasgal, presented to the AES 24th International Conference on Multichannel Audio, Banff, Canada (June 26-28 2003).
​
Ambiophonics: Achieving Physiological Realism in Music Recording and Reproduction
by Ralph Glasgal, Audio Engineering Society Convention Paper Presented at the 111th Convention, , New York, NY (Sept 21-24 2001).
​
Real Time Partitioned Convolution for Ambiophonics Surround Sound by Anders Torger and Angelo Farina, 2001 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics(10/6/01).
​
Ambiophonic Principles for the Recording and Reproduction of Surround Sound for Music by Angelo Farina , Ralph Glasgal, Enrico Armelloni, Anders Torger (7/22/01).
​
Improving 5.1 and Stereophonic Mastering/Monitoring by Using Ambiophonic Techniques
by Ralph Glasgal, Ambiophonic Institute, presented at the International Tonmeister Symposium, Schloss Hohenkammer (Oct. 31, 2005)
​
Ambidio -- Sound Stage Width Extension for Internal Laptop Loudspeakers
by Tsai-Yi Wu, Agnieska Roginska, and Ralph Glasgal, presented to the AES 136th Convention, Berlin, Germany April 2014
​
​
Tutorials
Envelophonics -- An Intriguing Addition to the Ambiophonic Repertoire by Ralph Glasgal
​
Myths about Ambiophonics Exposed
Ralph Glasgal
​
Guide to Ambiophonic Home Theatre
Justus Verhagen, Ph.D., ©2013
​
Understanding and Installing an Ambiophonic System
Les Leventhal and Ralph Glasgal
​
How Good Can Stereo Be? - Try Ambiophonics and See (speaker stereo v. speaker binaural)
Robert E. (Robin) Miller III ©2008
​
One Key to Ambiophonic Crosstalk CancellationRobert E. (Robin) Miller III ©2008
​
True-to-Life Sound Reproduction using
Recursive Ambiophonic Crosstalk Elimination (RACE)Ralph Glasgal and Robert E. (Robin) Miller III ©2008
​
What to expect to hear with Ambiophonics
Robert E. (Robin) Miller III ©2008
​
Caruso on Stage
Ralph Glasgal
​
Stereophonic Reproduction as an Artform Perfected by Stereophiles (not to be confused with the Stereophile magazine)
Ralph Glasgal
The Domestic Concert Hall
The true “You are there” experience with your hifi system is achieved by generating ambiance using real hall impulse response. This is what envelopment is all about, as Ralph mentioned in his Envelophonics paper.
To achieve this, additional speakers (small ones will do) are required. The process also requires a DAW and multi-channel DAC. However, as far as I know, no one outside the institute has managed to set up the DCH at their home. I am lucky to have managed it with Ralph’s help.
The Ambio Book.
Ambiophonics, 2nd Edition
Replacing Stereophonics to Achieve Concert-Hall Realism
For a PDF version of this book click here or here.
By Ralph Glasgal, Founder Ambiophonics Institute, Rockleigh, New Jersey www.ambiophonics.org
Dedication
To Johann Sebastian Bach, Richard Wagner, Gustav Mahler, and Lauritz Melchior, without whom we would never have bothered and to Manfred Schroeder, Don Keele Jr., Bob Carver, Yoichi Ando, and Ole Kirkeby without whose collective research we would never have succeeded.
Introduction
Ambiophonics: Recreating the Concert Hall Experience at Home
There are essentially only two ways for music lovers to enjoy music performed for them on traditional acoustic instruments. One is by going to a concert hall or other auditorium, and the second is by being elsewhere and playing the radio/TV/internet or a recording. This book and the techniques it describes are dedicated to helping you make the remote music-listening experience as audibly exciting as the live experience. Those audiophiles who share the dream of recreating a concert-hall sound field in their home, and who constantly strive to create a sense of "you-are-there," we have christened "ambiophiles". We call the science and technology used to create such an acoustic illusion "Ambiophonics". .....Read more
Listeners' Impression
"I’ve also heard numerous high-end multichannel systems, all of which couldn’t hold a candle to what we heard." - Howard Kneller, Soundstage Global.
​
"I downloaded the Hotto Ambiophonic Transcoder to use in reaper and wow what a difference! For the first time in my life I am hearing music the way it was intended by the engineer and the musicians. I tracked a band over the weekend and right away I can hear what's wrong in the mix. Everything is so apparent and in your face. I am no longer being lied to by the speakers and the room I am in. I can hear when reverbs and delays clash with each other so much easier now. Honestly, I can't ever go back to listening to stereo ever again. It's such a waste of time. How can something so awesome be so unheard of? Everyone should be able to hear music this way."
-- Paul Herlihy, recording engineer
​
..it's just beyond of this world...the clarity it gives you is simply amazing....even a bee...is just besides your ear.. click below for more
​
"XTC/Ambiophonics……WOW!
I spent the last day or so in the UK playing with the XTC (RACE crosstalk Cancellation) setup and was staggered by the improvement this can achieve in image precision, depth placement, stage width increase, and removal of crosstalk smearing. The improvements were both dramatic and particularly surprising given the fact that my arrangement of the LS1s is nothing like the optimum Ambiodipole configuration (probably around 50 degrees rather than the preferred 20 degrees or so). I can’t wait to try the XTC processing out in combination with the DRC!"
-- Andrew (TacT RCS user)
​
In the first few minutes after Chelvam had pressed a few buttons on his laptop, what I heard and the images it projected were astounding and unforgettable. I could hear the bird chirping behind me and the water flowing in front of me. I said to him, “I got it! I got it!”. Being shocked by what I had just heard, I asked him to stop as I wanted him to confirm that only the two speakers were active and no other speakers were active. Being not convinced, I suggested that he played some familiar songs and we settled on one of Norah Jones’. He was very confident and selected one and played. In the first few minutes, I could hear her soft voice in front and to be exact, in front and below my ear level. Suddenly, I heard the guitar was on my left (9 o’clock), not in front on the left (about 10 or 11 o’clock) which I would normally hear.
​
This was my first encounter with his 3D audio system. Truly I was fascinated by his system and the unexpected and shocking experience, thanks to cross-talk cancellation done at the application level in his laptop before the audio signals reaching the DAC. - Chua Ngak Keng
​
Kind words of Sharil who is also a reviewer of audio equipment. Unfortunately, it did not get into one of his audio sites. Here is one mini review of system by one of the the few reviewers in my country. You may also find others comments in the forum.
Quoting verbatim "After a a few months of chit chat over Whatsapp, I finally found time to visit STC's den to experience first hand what ambiophonics sounds like. Spent about 3 hours or so experiencing various musical genre and also a few 'settings'.Ir was 3 dimensional experience where music just envelopes around you in a very reliastic manner. Layer bu layer was of the music was exposed in such detail. The drum rolls on track like Black Magic Woman was presented in a manner that I could actually imagine how the drum set was configured. The soundstage was full but at the same time, the vocal was set smack in the middle and did not loose any prowesness. Bass however, was little shy to my preference. It was extended and not thud thumping bass. But I can do with a little bit more of a dive in the lower frequency.I can see why (but I dont understand why) audiophiles can reject this ambiophonics idea but experience it and let your emotion or hearing decide it. I certainly enjoyed it and if I ever have my own hifi room back, I may look into ambiophonics.
​
​
Video and Audio
I use DPA 4560 binaural mics to capture the sound of my system playabck. It gives you a general idea of the difference. The recordings are meant for me to do sound evaluation of my system.
​
Listen to hear the difference and please don't tell me about Youtube compression or you are listening through the phone speakers. Difference should be audible even with the cheapest device unless it is too subtle. Ambiophonics or the Domestic Concert Hall is not subtle and could easily pass double blind tests.
​
Unfortunately, not many recordings of system playback using binauatal mics. Reviewers do not want to use them as it will reveal flaws in their system and leaves no room ofr subjective evaluation. Some even resort to directional mics or closed mics so that the playback would sound good in the Youtube videos.
​
​
FB page of different systems sound.
​
​
​
This is my progress last 2 years. The video in reference too was recorded with binaural mics and listeners can hear the difference between stereo and Ambiophonics.
In this video you can hear the sound with all the 26 ambiance generating speakers and without.Please use headphones.
www.ambiophonics.org archive
About Me
Good sound through science
This website was recreated from Ralph's original website. Other materials are my journey to implement the concept.