3D imaging


I I started thinking about this yesterday. What makes speakers produce a 3D image? I figured the first thing is the recording itself. I'm guessing mic placement has a lot to do with this. Next I would imagine is room,and speaker placement. Downstream gear certainly has to have some effect on this. Does the crossover have something to do with providing this "illusion " for lack of a better term? 
     Now please understand,I don't have anywhere near the technical knowledge a lot of you folks have,so as you explain this phenomenon,please dumb it down for me! 
    Thanks in advance,
        Ray
128x128rocray
I just read a bit about Master Set a couple of weeks ago. Have you tried it,and if so,what were your impressions?
Not many people realize that there can be a tradeoff relationship between soundstage width and imaging precision.

Strong early sidewall reflections expand the apparent width of the soundstage but they do so at the expense of imaging precision, and this can include soundstage depth. Many people prefer this expanded soundstage width, but for the most 3D imaging from a given pair of speakers, strong early sidewall reflections should be avoided.

Note also that the ear is getting conflicting messages about the soundspace you are in: It is getting the spatial cues on the recording about the actual (and/or engineered) soundscape; and it is getting cues about the playback room. We want to encourage the former but suppress the latter. The early reflections are telling us that we are in a small room, so again we want to minimize them. In particular the early reflection off the wall behind the speakers tends to impose its signature on our impression of soundstage depth. Likewise a strong early-onset reflection from the wall behind us is conveying small-room signature.  Imo set-up geometry, reflection management, and diffusion are generally preferable to absorption for suppressing early reflections because absorption removes energy that would have been beneficial as later reflections, and absorption is most effective at high frequencies therefore it correspondingly alters the spectral balance of the reverberant sound (which is usually undesirable).

There is of course a lot more to 3D imaging than this.

Duke
I believe this is the first time I've heard anyone mention diffusion vs absorption at early reflection points. However,thinking about what you said about removing energy,it makes sense. Thanks for your post.
Diff + absorb + random = good, lots of variation in surfaces, textures, a loved in room is often FAR superior to the audio ph dedicated room with rack between speakers and a forest of amplifiers on the floor....