Ambiophonics --- WOW this is amazing!!

[flavio81]

Hi friends,

Today i tried Ambiophonics and it's nothing short of AMAZING, the best improvement i've heard on my system?

What is ambiophonics? It's easier to answer What Ambiophonics can do...

Ambiophonics can create a full, wide 180º sound field... using two speakers that are located close together in the center of the room. In other words, the soundfield projects way beyond the left and right speaker, with amazing clarity.

If you use 4 channels (4 speakers, 2 stereo amps), you can project a 360º sound field. Haven't tried yet, but should be amazing.

How is this done?

Ambiophonics uses psychoacoustics theory known from head-transfer-functions to cancel out the interference created between the two speakers. Using an algorithm that takes into account the distance between the speakers and the distance to the listener, optimizes the output to project a correct 180º soundfield. Left is thus placed left, right is placed right, but in a very wide soundfield, wider than the typical 60º achieved with common stereo speaker placement.

How can you try it?

Easy!! Try this free program that takes the audio input of your soundcard, applies the ambiophonics algorithm, and spits out the audio to your soundcard:

http://www.hotto.de/software/ambiophonictranscoder.html

You need to have the Java JRE installed. Download the ZIP, extract it and execute the JAR file. If you can't execute it, open a command line and type:

java -jar AmbiophonicTranscoder.jar

The program is only 14KB in size, those are the most glorious 14KB i've seen in my software engineering career.

[flavio81]

The webpage explains how to use the program, it works straight away but i suggest changing the Delay time until the soundfield is the widest. Right now i'm using two bookshelf speakers spaced about 30cm and i'm placed 1.5m away from the speakers. 45 microseconds seem to work best.

Difference between Stereo, Quadraphonics, Binaural, Ambisonics, and Ambiophonics

Stereo: Simply put, two (or more) microphones with 2 channel output. Instruments are typically laid out by the mixing engineer by using common panpots which only change the amount of Left and Right volume for the instrument. Or the soundfield is recorded using an XY microphone pair, Blumlein pair, etc. Soundfield is limited.

Quadraphonics: Basically the same as stereo but with 4 channels. Instruments can be placed on the back of the listener, on all 4 corners, but the ability to recreate the original soundfield is limited.

Ambisonics: Able to recreate a 360º horizontal soundfield using 3 audio channels, or a fully spherical soundfield (height included) by using 4 channels. Clever matrix system makes the same recording perfectly mono and stereo compatible. Ideally reproduced with 6 speakers or more.

All the systems above do not take fully advantage of psychoacoustical effects related to importance of the pnnae in localization, and do not use head related transfer functions and related techniques.

Binaural sound: Uses a special mic placement (typically a dummy head with microphones), recording into 2 channels, making a precise representation of the soundfield possible, at least when using headphones.

Ambiophonics: Takes advantage of psychoacoustics and HRTF to project a stereo or binaural recording over a 180º by using just two speakers close apart. A four channel recording can be projected over a 360º sound field using four speakers with supposedly life-like localization.

This is superior to 5.1 surround sound because of the "cancelling of the cancellation effects" introduced by the speakers.

Try it, it works!! I'm trying to find the drawbacks...

Note that the text above may not be 100% correct, it's based on my understanding so far.

[flavio81]

I was lying in my bed, listening to a classical music record, looking 45º to the ceiling and the sound was projected from left wall to right wall, like if there were speakers beyond the upper left and upper right corners of the room.

Amazing. And the best thing is that, as far as i know, this technology is free, not patented.

[flavio81]

No comments?

If you don't want to use any DSP or digital approach, you can do this simple setup that will work more or less in a similar way:



Just put a sound-absorbing barrier between the speakers.

I'm right now at the office using ambiophonics with the computer speakers. I am getting an about 100º soundstage... in my desk, with speakers that are just at the sides of the (small) computer screen... And with no "hole in the middle" effect!!

[JoeE SP9]

The Carver Sonic Holograph, Omnisonix Imager and Polk SDS speakers all do the same thing by canceling and compensating for inter-aural crosstalk. The HeadFi headphone amps have a similar circuit. I've tried some of them. Headphones and Polk speakers are not for me. The Carver and Omnisonix are occupying shelf space in a closet. The effect while interesting was veiling the sound.

I have a dedicated PC music server and I'll give the software a try on it.

There is some other interesting software on that site. I downloaded the Audio Mastering Suite which includes a bunch of things including the Ambiophonics utility.

I'll report later. Using the "ambio" utility requires moving my speakers for the best effect.

[flavio81]

The Carver Sonic Holograph, Omnisonix Imager and Polk SDS speakers all do the same thing by canceling and compensating for inter-aural crosstalk. The HeadFi headphone amps have a similar circuit. I've tried some of them. Headphones and Polk speakers are not for me. The Carver and Omnisonix are occupying shelf space in a closet. The effect while interesting was veiling the sound.

As far as i know, the way the cancellation is achieved is not the same as Carver's "sonic holography" nor "Sound Retrieval System" nor Polk's system.

[paul401]

Hi,
I recall reading a magazine article many years ago, on this subject, (probably early 80's and doubtless some hi-fi magazine of the time) in which it was suggested that holding an LP cover edge on up to your face whilst listening would give an illustration of the removal of crosstalk effect?!! It's the sort of article/image that sticks in your head.
Best try this when no one is around as you will look a little silly!

Paul

ps, the chap in the illustration appears to be standing on a "Segway"? Is this required for maximum effect?

[JoeE SP9]

The Carver Sonic Holograph, Omnisonix Imager and Polk SDS speakers all do the same thing by canceling and compensating for inter-aural crosstalk. The HeadFi headphone amps have a similar circuit. I've tried some of them. Headphones and Polk speakers are not for me. The Carver and Omnisonix are occupying shelf space in a closet. The effect while interesting was veiling the sound.

As far as i know, the way the cancellation is achieved is not the same as Carver's "sonic holography" nor "Sound Retrieval System" nor Polk's system.

It may not be exactly the same but the Carver and Polk systems worked by eliminating or cancelling crosstalk. This seems to do pretty much the same thing using an algorithm.

Carver also recommended placing the speakers closer together than normal.

I am going to try it.

[MonkeyBoy]

Joe, I used to have Carver amp and pre but the owner's manuals didn't mention anything about placing the speakers closer together than usual. Did I just miss it or was this something you read somewhere besides an owner's manual?

I don't blame you for shelving the Sonic Holograph. I was never impressed with it myself. I thought it was really nothing more that the usual ambience electronic trickery employed by the usual suspects not meant for truly serious listening but more along the line of gee whizzery.

[JoeE SP9]

I don't have a manual for it. It may be that it worked better for me with my speakers spaced closer together. It's been 20+ years since I used it.

[BobM]

Had a demo of this at Ralph Glaskal's house this past spring. What a system he's got! You can read and see some of it here:

http://www.ambiophonics.org/Kudos.html

It was definitely impressive on some things, but overly diffuse on some others. Ralph made me a disk copied from one I brought with me. He is now able to mimic the effect right on the recording, so you can listen to the original stereo recording, then play an Ambiphonics enhanced disk.

Yes, it is cool and does some things so very right, but I don't know that I would replace stereo with it for my own listening pleasure at home.

[kappa_man]

Just put a sound-absorbing barrier between the speakers.

Surely that would just kill your soundstage?

[flavio81]

The Carver Sonic Holograph, Omnisonix Imager and Polk SDS speakers all do the same thing by canceling and compensating for inter-aural crosstalk. The HeadFi headphone amps have a similar circuit. I've tried some of them. Headphones and Polk speakers are not for me. The Carver and Omnisonix are occupying shelf space in a closet. The effect while interesting was veiling the sound.

As far as i know, the way the cancellation is achieved is not the same as Carver's "sonic holography" nor "Sound Retrieval System" nor Polk's system.

It may not be exactly the same but the Carver and Polk systems worked by eliminating or cancelling crosstalk. This seems to do pretty much the same thing using an algorithm.

There are ways and ways to cancel crosstalk, and thus better or worse results. Ambiophonics is currently using the RACE algorithm which is different to what Carver and Polk did (otherwise they would be sued by them...)

[flavio81]

Just put a sound-absorbing barrier between the speakers.

Surely that would just kill your soundstage?

Quite the opposite, it expands the soundstage and allows much better localization of instruments. It is counterintuitive, but works. Try it!!

And don't call me Shirley.