What Does Holographic Sound Like?

"Regarding discussion of various technologies which produce the "holographic" soundstage, I have found no greater technology than the Omnidirectional speaker."

Agree, though as mentioned it is still quite possible with more directional designs as well with proper setup.

ALso certainly quality speaker designs including use of quality transducers are key. Poor quality in the speakers will likely greatly limit or mostly prohibit what might be obtained via other subsequent tweaks including to power otherwise.

I agree with Sabai that “holography” is difficult to achieve.

I agree with Newbee that ‘holography’ needs to be better defined.

I agree with Kijanki that shorter cables are usually better.

I agree with Al that shorter cables are not always better.

I agree with Douglas that daisy chaining cables produces a lot of confounding variables.

I agree with Al that cable performance is highly system dependent.

I agree with Mapman that good speaker placement improves “holography.”

I agree with Onhwy61 that good room acoustics improve “holography.”

I agree with Douglas that omnidirectional speakers improve “holography.”

I agree with Orpheus that the degrees of “holography” never end.

I agree with Csontos that Sabai might achieve even more "holography" if he changed his ratio of spending on tweaks vs. equipment.

I agree with Douglas that Sabai's experimental creativity should be commended.

I’m feeling agreeable today.

Bryon

"I agree with Al that shorter cables are not always better"

He mentioned exception of digital cables related to timing of the reflections, but shorter analog cables should always be better. I've never heard of anybody claiming improvement with longer analog audio cable, other than salesmen trying to find excuse to sell more common longer cable (1m vs. 0.75m or 0.5m IC) that he has in stock.

Mapman, I agree that either dynamic speakers or omni's can meet someone's expectations of holography.

But to get there one needs to thoroughly understand how the speaker propogates its sound and how the room will react to the sound. IMHO this is the most difficult aspect of audio and the one, which when absent, will most often keep folks from achieving anything much more than a pedestrian sense of 'soundstaging' certainly not anything aproaching holography as very well described by Sabai in his response to me. Clearly he understands how I define holography.

At the risk of being a pedant, or sounding pedestrian in this group, Omni's are very difficult to set up because one has to deal actively with the back wave, albeit there is much less problem with first reflections points.

Dynamic speakers (not dipole ones) are on one hand easier to set up and achieve an adequate sound stage (thought by many to be excellent) but which are handicapped by the user's lack of understanding of all of the set up issues. They know that they are lacking something but don't know what that might be so they fuel the tweak industry seeking the holy grail when all they really had to do was move the speakers a bit to deal with first reflections, including toe in which, by the way, is far more important than many think - folks seem to do this only to adjust tonal balance, not realizing the effect of first reflections off side walls and ceiling.

For example, many manufacturers recommend that speakers be set up so that they fire straight down the room. Why do they do this? Apart from possibly reflecting consideration for the speakers response on and off axis, because the first reflections off the adjacent walls will make an 'apparent' wider sound stage.

In the real world (mine anyway) i.e. our typical room, what this means is that the speakers have to be placed quite a few feet from the side walls resulting an adequate space between them to keep from rendering a congested center image, especially considering when the sweet spot is set up, but hey its wide! Consider that the only sound that should appear outside the speakers is out of phase sounds!

In that same room, you can place a dynamic speaker very close to the side walls (so long as it is not near a second room boundry (corner/back wall) IF you toe the speaker in so it crosses in front of the listener in his sweet spot and if necessary deaden the side wall surface adjacent to the speaker. That can easily create an uncongested stereo image which is as wide as the room behind the speakers, and incidentially because of the sound arrival time of each speaker create a much wider 'sweet' spot. It can also diffuse ceiling reflections as well which can be beneficial depending on height and surface. It can also produce a great sense of depth dependent on the space behind the speaker, the quality of the drivers and electronics, and lastly, IMHO, the effectiveness of any tweaks.

So, IMHO, as a practical matter it isn't nearly as important which type of speaker one selects as it is how well he understands them and how to use them in his room. Actually this is fairly scientific and predictible for those with the energy to research and learn.

FWIW.

On the subject of speaker placement and holographic image, one thing worth mentioning is that most speakers are set too far apart. I suppose many folks assume they will be able to obtain a wider soundstage do they frequently place the speakers rather far apart and toe them in as well. When I set up the speakers according to the XLO Test CD, specifically the Out of Phase track, I found, curiously enough, that the speakers presented a much more solid, deeper and wider soundstage placed about four (4) feet from each other, as opposed to say six feet - and with no toe in. XLO Test CD Test CD cautions that most speakers are placed to far apart. Obviously, the ideal distance for a given pair of speakers depends on at least a few factors. The ideal distance cannot necessarily be found by ear because you can easily wind up with a local maximum, not the real maximum.