Ambiophonics, What it is

Like tweeting, it is not feasible to describe something like Ambiophonics in a forum such as this. But basically Ambiophonics is so named as to be accepted as the inevitable replacement for stereophonics and 5.1 at least in the same sense that 5.1 has not replaced stereo and stereo has not really displaced mono. (Think news broadcasts, AM radio, telephones, shortwave, muzac, TCM. etc.). Like stereo and its cousin 5.1, Ambiophonics can be used to reproduce 2.0 or 5.1, 7.1, 10.2 etc. media. Also although one can make optimized Ambiophonic 2.0 or Panambiophonic 4.0 recordings using an Ambiophone, a normal Ambiophonic playback system is fully compatible with standard exsisting recordings. Also like stereo, Ambio is in the public domain. Anybody can make Ambiophonic products or use it without charge. TACT Audio, Ambio4you and several other companies are already making such products but it is a well kept secret, alas. Also, like stereo, Ambio comes in all price ranges including DIY and free. The real price is the intellectual effort required to unlearn stereo and understand Ambiophonic principles.

In brief, Ambiophonics in all its versions is a loudspeaker binaural methodolgy. In contrast, stereophonic reproduction (including 5.1) is based on an unusual sonic illusion akin to an optical illusion and as such has easy to demonstrate psychoacoustic defects that cannot be overcome, only tolerated. I use the term binaural to mean how we hear normally-nothing to do with earphones. Basically, binaural technologies, such as Wavefield Synthesis, Ambisonics, and Ambiophonics, strive to produce a home soundfield that closely resembles what you would have heard had you been at the microphone position during the recording session. For a variety of reasons, the stereo loudspeaker triangle cannot reproduce such a soundfield even if the recording, the media, and the reproducing equipment are perfect.

For audiophiles, who are not interested in the 3D reproduction of movies, video, games, etc. listening Ambiophonically to 2.0 media such as LPs,CDs, and MPs yields reproduction with greater clarity, depth, timbral fidelity, dynamic range, purity, perspective, pace, coherence, and musicality. In brief, you get more normal psychoacoustic realism even if you don't care about the wide soundstaging or creating a Domestic Concert Hall, as John Atkinson once termed this.

You can see a Domestic Concert Hall if you read the recent Bergen Record (N.J.) newspaper article at
http://bit.ly/hW4kwD
click at the bottom to see the second article.

Ralph Glasgal
www.ambiophonics.org

mep said:

All the things you mentioned as improvements are what audiiphiles spend big money on in hopes of improving those very areas. So now we have some whizz bang software/hardware combo that is going to bring us all of this? How long has your product been on the market and who is using it and reviewing it? Marketing claims/hype all read well on paper, but the bigger the claims are is usually proportional to the user disappointment. Anyone remember the Carver C-9 Sonic Hologram generator? How about all of those settings on your AVR receiver like "club" "stadium" "rock concert" etc. Does anyone really listen to those wretched settings?

Click to expand...

Ambiophonics is not a product it is a methodology like sterophonics. So far only a handful of suppliers offer Ambiophonic products and most users just use the free software files. Mostly, once you understand how Ambiophonics differs from stereophonics you can then do your own configurations just as you can with stereo. The products you mention were early attempts to correct the difficiencies of plain stereo. I am sure that if you can master the basics of Ambiophonics you may find ways to tweak it to taste just as one does with stereo. Basic Ambiophonics via just two speakers does not involve the newer extremely sophisticated concert-hall ambience features generated by convolution from real precisely measured hall impulse responses. But even if one does not like such convolved ambience, such surround sound options do not besmirch two speaker Ambiophonics any more then stereo is tarnished by the poor performance of 5.1 surround sound.

Actually, at the moment only very skilled computer mavens can utilize the concert-hall ambience programs and hundred odd hall impulse responses available. There is no component version available for normal audiophiles to use. Also adjusting the levels of a variety of ambient surround speakers is a lifetime occupation for perfectionists. Also, if you only listen to Chesky-like solo vocalists with guitar or small combo you don't need the ambience.

It would be great if one of the magazines would review or write an article about Ambiophonics but so far only the Bergen Record, a newspaper in New Jersey, has done so. http://ly/hW4kwD
(don't forget to click on the second part at the bottom) There are lots of postings on various forums and some of them are posted at www.ambiophonics.org

The sonic hologram was a brave attempt to solve the problem of stereo crosstalk. But at the time Bob Carver did not have digital processors available to do the job properly. He could only do a one shot cancelation whereas what is needed is a recursive algorithm. Also he did not realize that the speaker angle must be narrowed by about two thirds to correct for pinna problems. Lkewise some of the pioneering attempts at generating signals for surround speakers were not adequate. Are we not to play SACDs because 78s were not high fidelity in 1910?

But I really have to tell you that watching 5.1 movies or TV Ambiophonically via four speakers is where it's at. Also, two speaker stereo is an artform like black and white photography and going from stereo to Ambio is no more likely than expecting the black and white guys to adopt color.

Ralph Glasgal

As above, a physical barrier is as per audiophile requirements. It introduces no cables, no noise, no distortion, no frequency response changes, no concerns of analog versus digital, no controls, and so is an ideal 2.0 tweak. But this wall between your legs needs to be thicker than your head and ten inches or more is ideal. It needs to extend from the floor to a few feet above your head. It does not need to go all the way to the speakers, but it is good if the speakers are close enough to the far end of the barrier to be considered near field. The inner edges of the speakers should be about parallel to the wall and so firing along it. If the speakers are at too wide an angle the wall does not work well since sound goes around the end of it where you are sitting. RPG made such a wall years ago but you can just use a big mattress on end. See Stereophile, July 1988, Audio Video Interiors, Nov. 1995

If you can hear differences in cables then a wall like this is the only way you can go. If you are not in this category and also want to watch TV and movies Ambiophonically and in real surround, then you must use one of the new electronic versions of the wall. There are now free software versions, if you are into PCs, or audio components from Hong Kong and TacT if you are not and want other conveniences like remote control, 5.1 playback, and input selection.

Ralph Glasgal
www.ambiophonics.org
glasgal@ambiophonics.org

The Tom Danley experiment is not Ambiophonics. But his description does describe the difficulties in producing psychoacoustic versimilitude (binaural realism as opposed to the stereophonic sonic illusion) using relatively standard recording methods and the 60 degree loudspeaker triangle for reproduction.

The Ambiophonic group has developed a mic assembly called the Ambiophone which you can read about and see on the Ambiophonic site. This two or four channel device does make it easy to make full 2.0 or 4.0 recordings that sound great when played back Ambiophonically. You can sample some of these recordings by downloading them from the Ambiophonic website. The 4.0 DTS encoded demo tracks also need RACE processing of the front and rear pairs if you want 3D sound. Other samples are already RACE processed so you just need to put your speakers closer together and listen to what an Ambiophone can do. But note that like stereo the best results require that you adjust the RACE parameters for your own speakers, recordings, room, etc. so these pre processed samples may not be optimum for you. But the point is to compare stereo to Ambio while listening. You can do this just by moving up to the sixty degree angle and then back again to the approximately twenty degree angle. This way you can decide if you like to hear at least this 2.0 recording stereophonically or Ambiophonically. Hopefully, you will do this using your own favorite tracks sometime.

Ralph Glasgal

Steve Williams said:

Thanks Ralph

What is RACE processing

Click to expand...

RACE stands for Recursive Ambiophonic Crosstalk Cancellation. The details, equations and a block diagram are part of an AES paper posted on the Ambiophonic.org website. But in brief the early attempts at loudspeaker binaural as in Carver's Sonic Hologram, just sent a delayed inverted version of the right speaker signal to the left speaker (and the same for a left channel sound). The problem with this oneshot simple method is that the correction signal meant for the left speaker and thus the left ear, also goes past the head and reaches the right ear. So it is then necessary to get rid of this erroneous sound wave also. Thus to insure that the right channel sound reaches only the right ear and the left channel speaker sound reaches only the left ear you need a system that is iterative and seesaws until inaudibility. For other psychoacoustic reasons, it also can be proven that the speakers must be moved to a narrower angle which was something not underestood in the earlier Carver, Lexicon, and Polk approachs to this problem.

It took me some twenty years until I could get modern computer hardware that could do this in realtime so you could just play any recording this way (without using a wall).

Ralph Glasgal

In the main forum heading-

It is either ambisonics or Ambiophonics. There is no such thing as ambiosonics at the moment. Ambisonics is a 40 year old technology that is quite useful mathematically and in recording studios to process audio files or the output of a four channel microphone, normally a Soundfield. It is now mostly used to fabricate 3D soundfields for electronic music. It is not something that can be used in the home to play your exisiting collection of LPs. CDs, files, or DVDs. An acoustic recording of a symphony orchestra has to be made with a four channel microphone or even more mics and media channels if higher order ambisonics is desired. The more channels, the more accurate is the soundfield produced at the listening position. Four speakers is the minimum, but normally many more speakers are required including elevated and even depressed speakers. If you are a perfectionist, the ambisonic listening area is very small, normally about the size of a volley ball. But compared to the old quad arrangement (SQ, CD4) and now 5.1, surround sound ambisonics is certainly better, but not practical for home use or to play all those iTunes files out there not to mention all the existing discs.

Ambiophonics like stereophonics is simply a two or four channel playback method that many listeners and vendors can use if they wish to improve the quality of reproduction of two channel or fourchannel media such as LPs, MP3s, CDs, etc, or with four speakers, DVDs, BDs, SQs, etc. There are already a variety of Ambiophonic programs, apps, components, transcoders, VST plugins, etc. to suit the various listening worlds, just as stereo is used in components, PCs, tablets, smart phones, clock radios, cars, etc. There are also other loudspeaker binaural varieties related to Ambiophonics that go by other names. I am sure that by the time the decade is over, most listening of music and video will be via some form of Ambio, (spelled in Japanese) in that putting speakers at 60 degrees will no longer be necessary nor desirable for the best quality sound. The popular Soundmatters foxL speaker design, has speakers only 4 inchs apart! The popular Jambox licensed from Soundmatters, has a similar spacing. The Jambox now includes an Ambio like feature, but it is not adjustable as are the available Ambiophonic apps and components for that matter. But all this is just the beginning.

I don't see a way to get notice of replies so if you want me to seee a reply or get a reply from please me let me know directly.

Ralph Glasgal
glasgal@ambiophonics.org