I would like to take my views about the subject of the thread:

Be careful: Imaging vs. Compression

… a little further into radicalism, or closer to the naked truth. It might be (and most likely) will not agreed or in some cases not understood, still it is my conviction.

People who read my site know that I am a vocal and consistent opponent of “soundstage”. Imaging is a different category but I would like to keep Imaging out of scope of this conversation. The recent years some audio writing monkeys began to make fashionable to brag in their audio publications that they got less stupid and that “soundstage” is not their priority anymore. The sad irony is that it is not really true – they use to sell to fool-subscribers the notion of “soundstage” for years and now they just trying to use a new marketing tool: do not sell “soundstage”. Speaking personally with some of those people I realized that behind the empty words the new soundstage-haters have nothing, not to mention that understanding of the soundstage’s benefits AFTER soundstage rejection is too advanced subject for them to absorb.

Anyhow, I intend to rule out all existing explanations of Soundstage as dimensionality of audio recording and the explanations of it as a bi-product of stereophonic phase processing. I nominate a new cause of soundstage – a compression. I will not explain it – you do it, as well it is up to you to think further about the relation between soundstage  and compression. Still, here is a tip for further thinking: Imaging compete against compression but soundstage is benefited by compression…

Imaging is a property of listening perception. The soundstage is a property of sound reproduction.  Let me be a cryptic here and would give not the answer but a lead to the answer. Do you familiar with Home Theaters? It is absolutely imposable to build a properly performing Home Theater. Think why and founding the right answer you will found an algorithm to crack the Imaging vs. soundstage case.

To assess how far audio imaging from sound of a ”live” musical presentation we need to subtract visual experiences from perception, including the long-lasting visual experiences. I would agree that focusing ONLY on imaging can lead attention off beam, but it is no different from focusing on any other ONLY thing. Still, imaging is a playback is a phenomenal debugging tool that is one of the most sensitive tools to indicate problems. Does imaging exist in “live” sound? Sure, it does, we just do not acknowledge imaging as it is a natural part of our visual perception. However, the imaging-scenic perception is a process of recognition, contrary to soundstage -scenic perception that is a process of positioning.

Anyhow, I would not argue the subject of imaging vs. soundstage; I did it before many times, including the stolen by AA dirt debate in 2001. The subject that I would like accent in this thread is the relationship between compression and soundstage. I propose that soundstage is a derivative property of compression. Stripping compression destroys soundstage, increasing of compression makes soundstage more tangible. However, a mitigation of compression has practically no effect upon imaging. That was a point of my argument.

Romy the Cat wrote:

I propose that soundstage is a derivative property of compression. Stripping compression destroys soundstage, increasing of compression makes soundstage more tangible.

drdna wrote:

Is it possible that a simple experiment can be done with cassette players and the Dolby filter since this equalization affects compression for example? Adrian

Gregm wrote:

We may postulate that … compression is beneficial for soundstaging.

... You are right and it is very simple to witness. A high dynamic range creates less soundstaging and more imaging. Higher compression kills imaging and moves soundstaging forward. It is no surprise that to “sell the soundstage” is the most beloved deed for the Morons-reviewers who have been shilling crappy acoustic systems to public.

So, talking about postulating – I say that compression is proportional to soundstage. Here is the fanny part - compression is easy to measure. However, if the soundstage is proportional to compression and the compression is objectively measurable then why do not measure compression and just to calibrate the measuring instruments in “quantities of soundstage”.

I would even propose a fundamental unit of soundstage that I feel should be listed in the famous “Le Systeme international d'unites”. The unit of soundstage measurement should be a Moron and the following: nanomoron, micromoron, millimoron, kilomoron… etc… The device that measure the soundstage should be called Moronometer and any industry participant shell ware a Moronometer permanently attached to owner's pocket protector.

Romy the Cat wrote:

To assess how far audio imaging from sound of a ”live” musical presentation we need to subtract visual experiences from perception, including the long-lasting visual experiences.

ArmAlex wrote:

I think soundstage is artificially "injected" during recording. But Imaging is natural byproduct of proper speaker placement.

Mike, the speaker and other audio gear reseller, disagrees with me

http://audiofederation.com/blog/archives/595

He proposed his own take:

Federated Mike wrote:

Soundstaging: as the location on a virtual 3D stage of where a sound is coming from, usually on the side of the room where the speakers are Imaging: as the spacial and textural definition of the musician and or sound - their outlines, their weight, etc.

I am not accustomed to have debate with somebody for whom Audio is just a next mortgage payment. Still, having the Trade English as my sixths language I feel I need to translate the Federated Mike’s ideas into common-sense English. If to do so, then what Mike said would be the following:

Soundstaging: a tradable commodity that easy to demonstrate and to quantify to an ignorant customer.

Imaging: non-tradable useless notion as it does not allow sticking a merchant nose into somebody’s listening experience.

What is Realism in Sound Reproduction?

Realism in staged music sound reproduction will usually be understood to mean the generation of a sound field realistic enough to satisfy any normal ear-brain system that it is in the same space as the performers, that this is a space that could physically exist, and that the sound sources in this space are as full bodied and as easy to locate as in real life. Realism does not necessarily equate to accuracy or perfection. Achieving realism does not mean that one must slavishly recreate the exact space of a particular recording site. For instance, a recording made in Avery Fisher Hall but reproduced as if it were in Carnegie Hall is still realistic, even if inaccurate. While a home reproduction system may not be able to outperform a live concert in a hall the caliber of Boston's Symphony Hall, in many cases the home experience can now exceed a live event in acoustic quality. For example, a recording of an opera made in a smallish studio can now easily be made to sound better at home than it did to most listeners at a crowded recording session. One can also argue that a home version of Symphony Hall, where one is apparently sitting tenth row center, is more involving that the live experience heard from a rear side seat in the balcony with obstructed visual and sonic prospect. In a similar vein, realism does not mean perfection. If a full symphony orchestra is recorded in Carnegie Hall but played back as if it were in Carnegie Recital Hall, one may have achieved realism but certainly not perfection. Likewise, as long as localization is as effortless and as precise as in real life, the reproduced locations of discrete sound sources usually don't have to be exactly in the same positions as at the recording site to meet the standards of realism discussed here. (Virtual Reality applications, by contrast, often require extreme accuracy but realism is not a consideration.) An example of this occurs if a recording site viewed from the microphone has a stage width of 120° but is played back on a stage that seems only 90° wide. What this really means in the context of realism is that the listener has moved back in the reproduced auditorium some fifteen rows, but either stage perspective can be legitimately real. Being able to localize a stage sound source in a stereo or surround multi channel system does not guarantee that such localization will sound real. For example, a soloist's microphone panned by a producer to one loudspeaker is easy to localize but almost never sounds real.

In a similar vein, one can make a case that one can have glorious realism, even without any detailed front stage localization, as long as the ambient field is correct. Anyone who has sat in the last row of the family circle in Carnegie Hall can attest to this. This kind of realism makes it possible to work seeming miracles even with mono recordings.

drdna wrote:

Romy the Cat wrote: I propose that soundstage is a derivative property of compression. Stripping compression destroys soundstage, increasing of compression makes soundstage more tangible. Yes, I have no argument with anything you have said.  As I said before, I think the soundstage is an artificial distortion of the imaging, like a lens bending light.  I am inclined to agree since compressoin will shift frequencies, which are ultimately affecting timing.  And it is subtle timing changes with reflections that affect the imaging.  Is it possible that a simple experiment can be done with cassette players and the Dolby filter since this equalization affects compression for example? Adrian