Holographic imaging


Hi folks, is the so called holographic imaging with many tube amplifiers an artifact? With solid state one only hears "holographic imaging" if that is in the recording, but with many tube amps you can hear it all the time. So solid state fails in this department? Or are those tube amps not telling the truth?

Chris
dazzdax
Holography is a useful term for describing several attributes of good sound in audio together.

Carver's holography is an explicitly identifiable (analog) signal processing algorithm implemented in Carver equipment. When engaged, it improves the size of the sound stage and ones ability to identify specific players, instruments or recording elements within a more three dimensional sound stage. If you want things to sound more real, this is a good thing because these are attributes of a live musical performance as well that otherwise may often be lost with a 2 channel stereo audio playback system. It does in fact work very well when things are set up right and you listen from just the right place.

Carver is the only company that uses the term to describe a particular feature/function of their equipment that I know of, but I think the use of the term is the primary unique value.

Other equipment clearly achieves holography as well, through similar or different means perhaps, but they do not talk about much if at all, and the function cannot generally be switched in and out...its explicit in the standard operation of the equipment. Others more likely talk about the more commonly discussed elements of good sound that are typically present as well when holography is present, sound stage, imaging precision and detail, 3 dimensionality, bloom, etc.
Mapman, many of us associate holography with out-of-phase signals. Dark Side of the Moon and I Robot and Radiohead didn't get those huge images by accurately recording a performance in a real space. That's all done with signal manipulation. Carver does the same thing.

It can be very impressive to listen to, but it's not "real" except in the context that people like Alan Parsons meant it to sound that way. I love those recordings, but when I listen to the San Francisco Symphony play Mahler, I don't want it.

A system that adds it is performing a stunt, not unlike putting an effects pedal downstream from a guitar. Yes, it can be attractive, but is it the sound of the guitar, no.

Let's not confuse soundstage, bloom, depth, etc. with holography. One set of terms describes a real musical scene and the other describes an artificial effect.

Dave
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Dave,

I'm not necessarily advocating Carver holography, although I think the processing it does makes sense, it works as advertised, take it or leave it, and the benefits can far exceed the disadvantages. In fact, I no longer use the circuit because it is not required with my current set up.

The only speakers I've owned prior to the Ohm series 3's that I never found any value with using the Carver holography feature were the Triangle Titus monitors, which are so fast and detailed that the sound achieved a highly transparent, holographic effect on its own. Not true to the same extent with any other speaker I've owned including Dynaudio, Magnepan, and B&W or even original 80's vintage Ohm Walsh 2's.

Nothing that I've heard does holography as defined below (from wikipedia) as well as the Ohm series 3. You can move around the room and the perspective of the sonic image will change with you accordingly with little or no degradation.

Carver holography cannot do that. You have to listen from exactly the right spot otherwise the phase aspects you speak of come into play in a negative manner, not positive.

Let's face it that the whole concept of listening to music via a stereo system is in fact artificial and each system sounds different. All that matters is the end result and does it sound good to the listener.

I like the term "holographic" in describing audio though in the general sense that it captures multiple factors of good sound in a single term that describes what is needed to reproduce the complex live listening experience which is inherently 3 dimensional out of two boxes sitting in your room that inherently are not.

If a system does things well, there can be a holographic aspect to it that is a cumulative result of many other factors that we commonly discuss regarding good audio.

The end goal for everyone is this hobby I think is to make the reproduction of music in our rooms as real as possible. How can two little (or big) boxes capture what you hear live in 3-dimensions without the concept of "holography" coming into play?

A lot of things have to be going right for it to happen, and yes, there will always still be some things that do not go as "right" as others.

Below is the definition of holography from wikipedia. From this definition, how can holography be categorized as a bad thing when it comes to audio?

"Holography (from the Greek, όλος-hòlòs whole + γραφή-grafè writing, drawing) is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded. The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the recorded image (hologram) appear three dimensional. Holograms can also be made using other types of waves."