Which speakers do the hologram thing?

Sugarbrie's right about the room and electronics playing a big part. If those are right, the best I've heard at disappearing are the Pipedreams, the Avalons, the Audio Physics, the mbl 101s and my speakers (Sforzando JL-1s, not currently marketed). With the Pipes and the latter two, you can sit well off axis and "see" the performers as though you were off to the side at a concert, or even walk between and behind the speakers right into the soundstage.

Spica Angelus are imaging champs and pretty easy to set up, just don't get carried away with the gain knob on your preamp (I blew the woofers on my Angelus'during a party). Celestion 700's did a credible job as well, but in general I found "box" style speakers just aren't up to the task. In my experience the most holographic speakers are planars; I've owned Apogee Duettas followed by Martin Logan Quests and Aerius (the Quests are in my main system, the Aerius in my home office system) have been wonderful transducers. Planars are the way to go, but, be ready to invest a LOT of time moving them around in the room til you get the placement just right. Once you set up planars properly you'll never be able to go back to sealed box speakers for critical listening again. I've always used pretty good electronics so I really haven't noticed associated gear making a huge difference with planars (I'm referring to imaging only, of course any change in gear will be heard). Your choice of speaker wire will make the biggest difference with planars, experimentation is necessary. YMMV

What Sean has heard with the AvantGardes, I've heard with the A-Capellas, which are also modern horn loaded speakers. I see his point about dipoles, radiating out of phase towards the back wall. However, when you listen to live music in a room or hall, you never just have sound reaching your ears in phase, having all sorts of reflections from everywhere in the listening area. This is probably one of the reasons, why a well set up pair of dipoles in a carefully treated listening room can sound uncanningly real, more real in fact, than the A-capellas, which though beautifully holographic, will sound just a tad too "pure", ethereal, speak artificial, compared to say Sound Labs or Quads. Though more holographic, they cannot really sound "dirty" like live music and dipoles often do.

I agree with everyone that has mentioned Spica speakers. But nobody has mentioned the best Spica speaker. The designer himself said he liked the TC-60's the best. I have to agree with him. These speakers in a large room throw an unbelievably large soundstage.

Detlof, the thing with live acoustic instruments is that all of the sound is initially reproduced in phase and then is "distorted" or "delayed" by room acoustics & reflections. A single full range driver that radiates omnidirectionally in phase follows the same basic principles of the instrument it is trying to reproduce AND falls prey to the same culprit i.e. "room reflections" in like manner. In direct comparison, a dipolar driver is already distorted in comparison since it is contributing out of phase output at the same time it is in phase. It only gets worse from there in terms of the even greater problems associated with room reflections, etc...

I wonder what a panel type speaker sounds like with the back wave effectively nulled ? I've heard of guys building carefully thought out "enclosures" onto the back of them and being VERY happy with the results. This would give you the excellent transient response associated with these designs, get rid of the out of phase contribution that the back wave produces, increase low frequency output due to the lack of cancellation, should make placement a little easier, etc...

My thoughts are that a relatively deep "D" shaped cabinet with a curvature at the top and bottom would work best for something like this. That type of a design would not have any corners to produce standing waves nor have any parralel surfaces to aid internal reflections. An open "pocket" directly behind the panel would act as air spring tensioning, maintaining the panels linearity. The walls of the cabinet would be lined with a thick layer of insulation for internal absorption purposes.

I know that Newform markets ribbons something like this ( not sure EXACTLY how they are built ), so that may be something to look into. I don't think that any of them offer enough surface area to do low frequencies though, so it somewhat defeats the purpose of what i had in mind. Then again, we would end up with a front firing design that would probably lack the dimensionality, space and air that multi-directional designs seem to offer. Oh well.... Sean
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