[bigshot]

I agree, something seems fishy, he seems to know a lot about release dates and shipping costs to the UK for someone apparently living in New Mexico.

 
He says he is coming to the HeadFi Southern California meet. I've invited him to drop by my house for a demo of my system. We'll see what he says.

 

[bigshot]

  Either way I've mostly found my ideals in this heathen technology called Ambiophonics outside headphone land so I haven't participated in headphone discussions much recently.

 
What is Ambiophonics? That sure sounds interesting to me.

 

[Shike]

   
What is Ambiophonics? That sure sounds interesting to me.

 
Wikipedia has a solid intro on it:
 

Spoiler: Wiki Description

[size=13.63636302948px]Ambiophonics[/size][size=13.63636302948px] is a method in the public domain that employs digital signal processing (DSP) and two loudspeakers directly in front of the listener in order to improve reproduction of stereophonic and 5.1 [/size][size=13.63636302948px]surround sound[/size][size=13.63636302948px] for music, movies, and games in home theaters, gaming PCs, workstations, or studio monitoring applications. First implemented using mechanical means in 1986,[/size]^{[size=10.9090909957886px][1][/size][size=10.9090909957886px][2][/size]}[size=13.63636302948px] today a number of hardware and [/size][size=13.63636302948px]VST[/size][size=13.63636302948px] plug-in makers offer Ambiophonic DSP.[/size]^{[size=10.9090909957886px][3][/size]}[size=13.63636302948px] Ambiophonics eliminates crosstalk inherent in the conventional “stereo triangle” speaker placement, and thereby generates a speaker-binaural soundfield that emulates headphone-[/size][size=13.63636302948px]binaural[/size][size=13.63636302948px], and creates for the listener improved perception of “reality” of recorded auditory scenes. A second speaker pair can be added in back in order to enable 360° surround sound reproduction. Additional surround speakers may be used for hall ambience, including height, if desired.[/size]

 
Things that are similar but not quite up to snuff in the past would be Carver Sonic Holography, Polk SDA, etc. if you're familiar with them.  The difference is we now have recursive based elimination (RACE) and keep the front channels center to prevent pinna localization.
 
Definitely a love it or hate it thing for a lot of people.  If you like the sound of large panel electrostatic speakers, want sound that is able to go outside the normal stereo triangle, and enjoy experimenting with DSP it's definitely worth playing around with.
 
If interested the ambiophonics homesite includes tutorials, whitepapers, AES stuff they presented, etc:
 
http://www.ambiophonics.org/
 
I dipped my toes in and now have a dedicated setup for it.  I have a panambio setup, except with music I use a 50% wet convolved signal on the back rather than adding extra speakers for ambience.
 
EDIT: fixed HRTF to Pinna

 

[davidsh]

  Okay, which one of you guys is copycatting me at innerfidelity?  Pretty funny
 

Interesting debate there...
 
Ambiophonics, guess I should research more before asking question, but how do you get around the problem that resonances and frequency response can change (a lot) if not in the right listening position?
 
After reading a lot of different threads, including the one posted about synergistic research I feel a whole lot of conspiracy creeping up on me. The audiophile world is hard to navigate.. Now I begin to doubt head-fi and its motives, too. Conspiracy, I say 

 

 

[Shike]

 Ambiophonics, guess I should research more before asking question, but how do you get around the problem that resonances and frequency response can change (a lot) if not in the right listening position?

 
Well you have to listen in the sweetspot much like you would a narrow dispersion ESL.  Since the speakers are place close together (30 degree total angle max compared to the 60 of a normal stereo triangle) means that reflections and resonance should usually be quite similar.  It also helps with room reflections as they should be more uniform than not.  Another note on resonance is that ambiophonics usually employees a high-pass and low-pass so it isn't applied to the lowest lows and it stops before any real high treble comes in.
 
I'm sure you can find more in-depth explanation on the site, I'm just paraphrasing from what I remember at this point.

 

[bigshot]

   
Wikipedia has a solid intro on it:

 
Do you have a floor plan for speaker placement? Is it a second set of mains tight in against the center channel? I may be doing a really primitive version of that already. I have two sets of mains. The true mains are 16 feet apart and are EQ'ed full range, handing off to the the sub at 60Hz. The second set of mains are six feet apart and are EQed to favor midrange and upper mids. The center channel covers a full spectrum from about 160Hz up. Overall the EQ of all of them together is flat. The layout localizes centered vocals and guitar solos better in music, filling in the phantom center completely; and focuses the dialogue across the full width of the projection screen (ten feet) in movies. The effect, when I use it with Yamaha's stereo to 5.1 DSP is to create a huge soundstage about 20 feet wide and 15 feet tall with pinpoint accuracy if the recording is miked realistically.
 
Is that similar?

 

[Shike]

   
Do you have a floor plan for speaker placement? Is it a second set of mains tight in against the center channel? I may be doing a really primitive version of that already. I have two sets of mains. The true mains are 16 feet apart and are EQ'ed full range, handing off to the the sub at 60Hz. The second set of mains are six feet apart and are EQed to favor midrange and upper mids. The center channel covers a full spectrum from about 160Hz up. Overall the EQ of all of them together is flat. The layout localizes centered vocals and guitar solos better in music, filling in the phantom center completely; and focuses the dialogue across the full width of the projection screen (ten feet) in movies. The effect, when I use it with Yamaha's stereo to 5.1 DSP is to create a huge soundstage about 20 feet wide and 15 feet tall with pinpoint accuracy if the recording is miked realistically.
 
Is that similar?

 
I think it's going for the same end game, but yours uses localization while ambiophonics tries to eliminate localization of the speakers so that the recording provides it instead if that makes sense.
 
First, ambiophonics only requires four speakers though more are welcome as ambiance speakers.  For HT the center channel is simply downmixed to the front.  The two main speakers are put close together to create a very tight angle, and the same with the rear speakers, like so:
 

(from the Ambiophonics site)
 
 
Then acoustic xtalk cancellation is used - the newest cutting edge is RACE.  I'm quoting the explanation of it here:
 

 

The basic crosstalk canceling technique we have developed and are making available free to the internet community is the Recursive Ambiophonic Crosstalk Eliminator or RACE. Recursive is the operating word. When a signal from the left speaker undesirably reaches the right ear, it must be cancelled at that ear by an inverted, perfectly delayed, slightly lower level replica from the right speaker. But this cancellation signal will also reach the left ear and so it must also be cancelled (2

^nd

 order cancellation) by a properly conditioned signal from the left speaker, which signal then also reaches the right ear requiring another round (3

^rd

 order) of cancellation, and so on. For a greater tolerance for non-ideal speakers, to avoid frequency response errors, and to enlarge the listening area, this recursive “ping-pong” correction needs to be carried out to inaudibility. We have demonstrated that up to five people can hear the same wide stage even from two small speakers using this method.

 
Link to figure 2: http://www.ambiophonics.org/images/RACE%20flowchart.png
 
If properly miked as you mentioned the sound can be perfectly centered to +/- 85 degrees on either side from center.  Panambio provides back speakers which you want to do the same thing with.
 
Then a cool trick for music is that you can add additional speakers and play 100% convoluted sound of a hall (Waves VST and impulses) to create ambiance.  In comparison I use 50% wet signal on the rear channels which gives a similar effect.
 
 
The downfall to this method is that you must be in a line with the speakers so if you have more than one person they would have to be in-front or behind.  My ambio rig is fixed at my computer desk and my HT/anti-sweet spot setup is composed of omni speakers for this reason.
 
 
I think the best explanation of the theory and working is in this understanding/installing tutorial:
 
http://www.ambiophonics.org/Tutorials/UnderstandingAmbiophonics_Part1.html
 
This will explain it infinitely better than I could.

 

[bigshot]

It looks like that would work best in a fairly small room. kind of like those racing simulators at game arcades where you get inside a cockpit.
 
This is like the mirror opposite of what I do. Instead of trying to expand the soundstage into a large solid field, your system makes a tiny compact densely organized one that you sit close to. I guess the accuracy of the field depends on how tight together everything is.
 
It would be a LOT easier to get a small installation tuned properly than it would a traditional large room 5.1 system. I really didn't have a choice, because my system is wrapped around a ten foot projection screen. But I can see for apartments and bedrooms, that would be a huge advantage over bookshelf stereo speakers or headphones.
 
I'm convinced that the future of high end audio lies in DSPs and multichannel speaker installations. I'm itching for Atmos, but the shape of the roof of my listening room would be impossible to control. It has a high peaked ceiling, and I just know if I flew speakers into the rafters, it would end up being like a ping pong game of reflections up there.
 
One thing I would really like to have someday is 8.1 with two side speakers and a center channel in the rear to bridge the phantom center behind me. I think that would complete the mesh of the sound field in the middle and allow for some pretty sophisticated room ambiences and instrument placement within the room itself.
 
My speaker configuration is pretty unconventional, but within the context of the room, it works great. The mains are in a semi circle in front. The center and rears are elevated slightly above the listening position, and the mains are ear level. The sub fires in along the floor. The number 1 mains are toed in slightly. The effect this creates is a wraparound soundstage up front with a front to back tipped slightly down, like you are in orchestra seat risers slightly above the performers. With classical recordings and jazz, this arrangement works real good, and the nice part is that it is absolutely perfect for movies too. The far end of the couch is a little dicey sound wise and angle wise on the screen, but it's perfect for lying down with your feet pointing at the screen.
 

 

[Shike]

 I guess the accuracy of the field depends on how tight together everything is.

 
The front channels have to be tight together, but it will work as long as you're centered and far enough away to generate a tight angle for the lower delay levels.  For example if the speakers surrounded a 5' screen you would need to sit ~10' away at the least (basically double whatever the separation of the front speakers is).  Thankfully since I'm using my old NHT SZ XU speakers they are basically less than an inch apart.
 
 
The biggest advantage of the smaller setup is probably ease in centering the sweetspot, but it isn't just for small rooms:
 

 
That's from the main ambiophonics page - it's a panambio setup with tons of ambience speakers and driving electronics.
 
The biggest disadvantage though is what you mentioned - having to surround a screen.  With the right acoustically transparent screen for a projector you could fire straight through it, the other option is having the screen above the speakers or vice-versa - hopefully without making it uncomfortable.  Still - it really only works for single person viewing which is why I use omni in that situation or view at my PC.
 

 I'm convinced that the future of high end audio lies in DSPs and multichannel speaker installations.

 
Agreed.  My software chain looks like a nightmare though having to use voicemeter>audiomulch>ElectriQ>electro-music ambio VST>Waves Convolution (for music - otherwise bypassed>Dobly Digital Live> finally out >_>'

 

[Roly1650]

Agreed.  My software chain looks like a nightmare though having to use voicemeter>audiomulch>ElectriQ>electro-music ambio VST>Waves Convolution (for music - otherwise bypassed>Dobly Digital Live> finally out >_>'

This looks very interesting and the cost of entry is modest, I already have most of the hardware for a four speaker setup and no screens to worry about, music only. This may be a dumb question, I haven't waded through all the links you provided yet. You have implemented your setup entirely through your pc, so the pc is the source, right? If my assumption is correct, what are the pros and cons of doing it your way as opposed to standalone dsp's? I should add, I have a bit of an aversion to software piled on top of software, but that's just me!

 

[Shike]

This looks very interesting and the cost of entry is modest, I already have most of the hardware for a four speaker setup and no screens to worry about, music only. This may be a dumb question, I haven't waded through all the links you provided yet. You have implemented your setup entirely through your pc, so the pc is the source, right? If my assumption is correct, what are the pros and cons of doing it your way as opposed to standalone dsp's? I should add, I have a bit of an aversion to software piled on top of software, but that's just me!

 
Sorry for the late replay.
 
1) Yes, PC is the source - there's ways of implementing it without a PC - MiniDSP has released Ambio units which will get you pan ambio - no convolution, but if you reduce the volume of the back channels it will expand the width a slight bit further according to some of the pages, just dial in where it sounds good and leave it.
 
2) Complexity and cost most likely.  Depending on what you're intent is a simple stereo setup can be done with a single VST.  When you involve convolution, panambio, etc. cost and complexity goes up.  I'll be happy to answer any setup questions I can as to what's the best solution IME.  You also need a a somewhat faster PC if you plan on doing anything on the PC while it's doing its magic - I use a i5 2500K and hit roughly 5.5% CPU usage in Audiomulch.  The latency isn't too high but faster is always better in this case.  This is of course if doing anything beyond simple stereo, if only doing stereo and music it's unlikely even somewhat older PCs will have much an issue.
 
3) Your aversion is somewhat justified - there is a lot of software chaining going on in my config.  You have to do some research and work to get it to function how you want.  Then again, with someone that has already done it the setup should be substantially easier . . .
 
If you want to just do a simple stereo test the VST alone is $10 at electro-music.  You pay, and they eventually email you a link.  Turn around and make sure you get version 1.2.  From there put your speakers right next to each other, sit so you have a total of 30 degree angle (15 per side) max.  Use a plugin to use the VST if using FB2K or use it natively with jriver.  Pop up the VST and lower the delay to 45ms, up recursion to 50%, volume max, zentum up a bit if you want the center to be a bit forward in the stage (I set it to one), and adjust space till it sounds reasonable (I have it at 3.0 myself).  That will give you the effect with a very straight forward sound, possibly in the studio with the band is how I'd describe it.  To get the "live" type sound takes a lot more work, and the more realistic you want the more work/equipment it needs.  I think mine is a nice happy medium.

 

[Roly1650]

Sorry for the late replay.

1) Yes, PC is the source - there's ways of implementing it without a PC - MiniDSP has released Ambio units which will get you pan ambio - no convolution, but if you reduce the volume of the back channels it will expand the width a slight bit further according to some of the pages, just dial in where it sounds good and leave it.

2) Complexity and cost most likely.  Depending on what you're intent is a simple stereo setup can be done with a single VST.  When you involve convolution, panambio, etc. cost and complexity goes up.  I'll be happy to answer any setup questions I can as to what's the best solution IME.  You also need a a somewhat faster PC if you plan on doing anything on the PC while it's doing its magic - I use a i5 2500K and hit roughly 5.5% CPU usage in Audiomulch.  The latency isn't too high but faster is always better in this case.  This is of course if doing anything beyond simple stereo, if only doing stereo and music it's unlikely even somewhat older PCs will have much an issue.

3) Your aversion is somewhat justified - there is a lot of software chaining going on in my config.  You have to do some research and work to get it to function how you want.  Then again, with someone that has already done it the setup should be substantially easier . . .

If you want to just do a simple stereo test the VST alone is $10 at electro-music.  You pay, and they eventually email you a link.  Turn around and make sure you get version 1.2.  From there put your speakers right next to each other, sit so you have a total of 30 degree angle (15 per side) max.  Use a plugin to use the VST if using FB2K or use it natively with jriver.  Pop up the VST and lower the delay to 45ms, up recursion to 50%, volume max, zentum up a bit if you want the center to be a bit forward in the stage (I set it to one), and adjust space till it sounds reasonable (I have it at 3.0 myself).  That will give you the effect with a very straight forward sound, possibly in the studio with the band is how I'd describe it.  To get the "live" type sound takes a lot more work, and the more realistic you want the more work/equipment it needs.  I think mine is a nice happy medium.

Thanks for the info, I may give it a go this winter.

 

[bigshot]

Well, I guess we couldn't avoid it. We'll have to create a new thread for the test results when they come in.

 

[Head Injury]

As long as the next thread doesn't go off on a religious tangent and isn't reported to clean up less than a page of it, they won't have an excuse to permanently lock the whole discussion.

 

[SilentFrequency]

As long as the next thread doesn't go off on a religious tangent and isn't reported to clean up less than a page of it, they won't have an excuse to permanently lock the whole discussion.

I didn't know religious talk was disallowed until it was brought up on that thread by another member shortly before thread was locked.

But now I know I guess, must re-check the rules again though myself!