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Old 27th January 2013, 05:41 AM   #781
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Hey Michael, thanx for the article.
I'm glad the word is getting out.
The only thing that bothers me is that the ambiophonics institution is not getting enough credit.

It's not 3D sound........
It's ambiophonics!
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Old 27th January 2013, 01:51 PM   #782
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You're welcome! I thought it was a pretty good and detailed article for a general interest magazine. I'm sure it went over the heads of many readers.
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Old 24th February 2013, 10:11 AM   #783
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I finally managed to find some time and build a decent barrier.
I used 4cm thick extruded polystyrene covered with 3cm acoustic foam on both sides, the panels holding with a wooden frame, total size 1.3x1.8m high, placed in the middle of my living room, >2m away from boundaries.
I did a 6h listening session, starting with a very cheap dinky 2way then swapped with the Orions. Both speakers against the barrier, so a very narrow angle.
I sort of knew what to expect as I had a preliminary experience more nearfield with the Olasonic and a 50cm barrier.
Sorry for the lack of pictures, can't find the camera (blaming the wife..).

So I started with the tracks I knew would produce most differences against a stereo setup, namely Jarre Oxygen and Equinox, Roger Water Amused to Death, Telefon Tel Aviv, Kraftwerk, Kenji Kawai. Very processed studio music with out of speakers effects. Well, I was absolutely blown away, it is just incredible and very, very hard (impossible?) to go back to the stereo triangle. The music spreads nearly 120°, tracking precision is scary and I rediscovered things I thought I knew by heart, I still remember when my father bought the Equinox tape when it came out.
Magical.

Then things got more complicated with classical music.
RCA living stereo/Mercury living presence: used about 5-6 of each, works well, but I prefer classic stereo. I did though hear details unknown to me, especially ambiance wise and again, tracking is better, but as an overall experience, wouldn't be my first choice.
EMI Celibidache collection: very good, I hear the hall better, could well live with that.
BIS: Bach with Suzuki, Britten with Jarvi. I had high expectations given the recording philosophy, but it was a miss. Stereo spread works much better.
Decca: Haitink on Shostakovitch's 8, one of my favorite. Again, very nice but it failed to produce the experience the dipoles give me. Jacques Loussier "Lumieres", same thing.
Fabio Biondi's original 4 seasons: same thing.
Missa Criola: very good, but not better than stereo, a draw.
Preisner Requiem for a friend: better on stereo.
Gorecki Requiem: very good, a draw.
Telarc Carmina Burana: very good, better than stereo.
Chandos Medtner piano concerto: better on stereo

Linkwitz test disc: much better! wow, impressive on all tracks.

ECM: used a lot of different ones as I like the label very much. A total miss, very congested sound focused in the middle only. I was really disappointed.

Chesky: Body Acoustics, Marta Gomez, Oregon, Swing Live, I Ching, Jen Chapin, Olatunji. Good, but not better, a draw.
2L: Nidaros and Trondheim Solistene, better on stereo.

To be noted that the Orions, although much better, did not give their best in the application, the sound sticked more to the speakers then with the dinky 2way.
I also tried to spread the speakers more keeping the barrier, the effect collapses somewhat.

Voila!
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Old 25th February 2013, 03:47 AM   #784
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Thanx for your impressions lolo
Maybe the thing with symphonic music is that it is preferred to have the pinna cues coming from further out to the sides, also it may not be as degraded by the comb filtering that is present inbetween the speakers in a stereophonic set up. This may be due to the fact that there are large sections of musicians, so they don"t need to have pin point imaging.
I like to use RACE instead of a barrior because you can control the amount of crosstalk cancellation. What I do now is keep the speakers at 30 degrees and only apply enough attenuation on the RACE filter to spread the image to 60 degrees (blumlen standard).
This way pinna cues are in the middle of dead center and 60 degrees apart. Another benifit is you do not need a lot of cancellation so that means less erratic frequency behavior at the top end, and less unessisary bass cancelation.

If you just use the barrior, you are getting headphone like spread (120 degrees or so) with the exception of high frequencies which will be coming from center. This might be good for processed music or Roger Waters Q sound, but it will sound unatural with live music because of the disconnect between the pinna cues (high frequencies comming from middle) and the rest of the frequency spectrum comming from the entire listening window.

As for why it sounded better on the monitors rather than the Orion I cant answer.

I have an EMC recording of Steve Reich "Music for 18 Musicians" and there is not a lot of seperation in it, almost sounds mono compaired to other label's example of this recording.

Try Pink Floyd's "The Final Cut" with the barrior. They used a dummy head for that album. It's a hybrid stereo-binaural.
My favorite with ambiophonics is Dead can Dance "Spirit Chaser" that one will really blow your hair back
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Old 25th February 2013, 07:02 AM   #785
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lolo, thanks for sharing.

after ambio barrier, I've only used 1 speaker. But I'm getting back into surround soon (in another room).

the crickets in Roger Waters "Amused to Death" alblum went way out there with 2 x 3" tang bands (10" between centers) about a foot in front of you. Didn't need a barrier, highs were directional already.

i'll check for Final cut.......
ty melo

norman

Last edited by norman bates; 25th February 2013 at 07:06 AM.
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Old 25th February 2013, 08:23 AM   #786
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De rien!

The thing is it depends very much on the recording really. If everything was done with an omni mic some distance from the event, it would sound bloody great on ambio, but what to do with the millions of past records?
I will keep this solution instead of headphones I think, as 2nd system with a small FR and a foldable small barrier, for late night sessions.
It was very worth trying, thanks for pushing me Melo!
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Old 26th February 2013, 11:46 AM   #787
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Quote:
Originally Posted by poldus View Post
There is something going on that I donīt understand. There is Ralph Glasgal and then there are a very few of us who said: this is totally better than stereo, there is no way we will go back.
Where is everybody else? How come they donīt hear the overpowering superiority of ambio?
Quote:
Originally Posted by Melo theory View Post
Well, Poldus.......
People who aren't interested in, or don't know about ambiophonics aren't looking at this thread.
...
Hi all,

Ambio fans are here, maybe a bit more shy (?) than would be usefull

Me, I posted on ambio on 2 separate forums, and demonstrated in my house, hoping to get the word out. It's OK, some will come forth, some will not .

Anyhow, my humble 0,5c on the topic:

Although I read about the Ambio method in the late '90's in a local audio mag, I did not pay much attention to it. I first tried it in early 2011 and all I can say is how very much I regret having lost so many good listening years.

Much like poldus, my first impression was that the ambio setup was giving me by far the best sound I ever got from the system. Also, I second pedroskova in that the new setup gave me more detail, which in short I can describe as:
- A very solid image with excellent focus. The image remaining stable even when moving my head about the barrier, though not lifting myself up from the listening seat.
- An expansion of the stage far beyond the positions of the speakers. I estimate a stage of more than 100* (degrees), alas depending on the recording.
- Improvement in both the width and the depth of the stage, and an increased ease in separating between the musical happenings.

What at first I did not achieve was to "reconstruct the sense of space in a recording", although I believe in some cases I came close - as with the Bill Evans Trio, live at the Trident club. Guess that's better done with 4 speakers and PC power...

On speaker angles and distances: I started with 34cm / 1' of separation between center of drivers, speakers 2" appart looking straigth forward, my head about 2 meters away, which is roughly an 11* angle. Slowly but surely I started decreasing the listening distance to ~140 -150cm. Now I am about 1m / 3' from the speaker plane, on a mild toe-in, and still loving it.

As for the barrier, for my first attempts I came up with a simple one made up with hard cardboard between pyramid foam, total width about 7". That was light and easy to move about, good for listening comparisons between stereo and ambio, but obviously would not hold much of the lower frequencies. I then moved to 6" thick polyester fibber absorbent panels. That seemed to hold more of the lower register, but also suck up a good percentage of the high band.

Looking to get the top octaves back, I tried the tempered glass from a rectangular IKEA table (in its cardboard packaging, he he ). This rather reflective barrier proved very effective in both keeping the signal between speakers separated and not blocking the higher frequencies. At least that’s what the music images coming alive suggest. Plus, it frees up more absorptive panels to be used against those nasty room reflections. But it's a pain to move about and, being very thin at under 2", has me sitting with me back straight and me forehead pressed against it to get that good LR spread. Well, no pains, no gains, even with ambio... just wait until I have me carpenter cut out a place for my legs on a 1.5" 8'x4' mdf panel

Summing up my experience: Ambio works great, aint' no going back to stereo for me. Also: more absorption around the room is better than less, especially in my small room, at least to these ears. A 180* stage with a plain barrier is possible, depending also on recording obviously. Best trick / way to go there is to keep head close, even pressed against the divider, be that a wide or narrow one. The divider, that is, not the head Else, a 100* to 120* stage is still very common. One more detail: I kinda like the barrier not to touch the speakers, seems to give the center images more presence / detail. Not sure what/how, maybe sound diffracting round the baffle edge works towards that.

Finally, on the question on speaker compatibility / barrier necessity: I have been keeping my ears open for speakers so directional that they may go without a central barrier. I have taken an interest on the holosonics and the panphonics implementations that claim a dispersion of up to 5* before the power response drops by 20dB:
Audio Spotlight - Add sound and preserve the quiet.
Panphonics Oy | www.panphonics.com
Now, these are very directional speakers. Not sure how they measure up as hi-fi though... And, with the (bank) crisis taking heads down here, I'm not likely to test them myself anytime soon ... but if any of you ambio followers take a swing at them, do let me know, will ya?

As a closing statement: Ambio rocks!
Many thanks to Mr.Glasgal for pursuing the idea and kudos to all folks brave enough to stray from the stereo norm and support it.

Best,

Charlie

PS sory for the loooooooooooong post, just hope it was worth a read!
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Old 26th February 2013, 04:03 PM   #788
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damn, maybe my barrier was too flakey?? On most recordings I only got 60/70 deg.. :-(
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Old 26th February 2013, 11:28 PM   #789
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Hi Lolo,

I went through Keele and Bock's paper again. In 5.2 they say the barrier should be made from a rigid material. Still they used a reflective divider instead of absorptive panels.

If you select absorption instead, then IMHO the 3cm foam over polystyrene sheet is not up to the task. The foam is too light and too thin to make for a respectable absorption barrier. The extruded polystyrene is not helping much either, as it is also light, mostly see-through sound-wise. Please read more on polystyrene in

Info sheet 1 Frames Page and

Dow Building Solutions Answer Center

Surfing and reading, I found that acousticians accept a material as an effective sound absorber at a certain frequency once the absorption coefficient rises up to about 0.8. Don't see how thin foam and polystyrene will work well in frequencies below 1kHz, maybe even 2kHz.

Materials known and commonly used for absorption - glass-wool, rock-wool, polyester-wool - also do not work well under 250-500 Hz, unless they are very heavy or are used in multiple layers. Hence the suggestion for thick barriers: use a medium density (say 40-50 kg/m3 ~ 3pcf or more) material of absorptive properties in multiple layers (total thickness >= 4-5") to achieve even absorption from 200Hz up to 5-6kHz.

Middle room placement of the barrier can help push down the lower absorption frequency, but even so, any absorptive barrier is not likely to do much under 100Hz. Using a higher density absorptive material in smaller thicknesses will absorb better at low to mid octaves (say 200 up to maybe 1khz) but will do less well over these frequencies.

My suggestion: before you go out searching for new materials to replace your existing barrier, try moving much closer to it. Does that give you a wider stage? If not, can you do another test but with some plywood or mdf sheets instead? As Keele and Bock say, the rigid panels do not have to be too thick, even less than an inch will do. But, you still need to move closer to the divider...

Best,

Charlie
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Old 26th February 2013, 11:42 PM   #790
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Forgot to mention, sound wave angle of incidence seems to play a role on the absorption capabilities of said materials, always depending on frequency. Hope that for our application of a barrier, the a coefficient will not change much.

Is it my impression, or does the rigid / reflective barrier start looking better now? I mean, you just pick a slab of plywood or mdf (which can be very heavy indeed, and thus block low frequencies well), cut off a piece for the legs so as to bring torso and head close to the barrier at the seating possition, and that's that! No need to hassle over selection of absorptive materials, calculating coefficients, or worrying over airborne particles from the acoustic insulation..
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