There is lots of talk on hi-fi forums and hi-fi magazines about sound stage and of course lots of it is rubbish.
A so called sound stage is created by using two or mores speakers and feeding more than one channel of music into the speakers.
We have got two ears and having two ears helps us to locate the position of a sound quite accurately most of the time. We locate a sound by hearing volume differences between our ears and by the timing differences that a sound takes to move from one ear to the other.
When we listen to an orchestra playing live we can locate the positions of the various instruments in both the lateral and vertical planes. An orchestra generally positions the violins on the left as you are facing it and the cellos and double bass instruments on the left and so on. The woodwind is generally in the middle. Our hearing and perception enable us to determine the location of the instruments with our eyes closed. But, of course, our perception and hearing can be fooled by echoes and hall acoustics. Anyone who regularly attends orchestral concerts can verify this.
When stereo recordings became generally available in the 1950's sound engineers used recording techniques and microphone placement to generate a similar sound ,when reproducing the sound an orchestra, so that a listener could appreciate the sound stage in his living room, but of course the stereo speakers had to be placed correctly and wired correctly.
If you listen to a good recording of an orchestra through a hfi-fi quality sound system then you will be able to hear an approximate positioning of the instruments. This of course depends upon the acoustics of your listening room and your position in it. Your perceptions are assisted by an expectation bias that an orchestra always positions the instruments in a "standard" configuration. No sound recording can achieve an exact duplication of the original sound stage.
Now to the rubbish that is spoken. If you do not have access to the original master recording you cannot verify that the sound stage from your hi-fi matches reality. You cannot know where the instruments where originally positioned and whether the original master recording had a 3 dimensional sound stage or not. Modern recording techniques using electric guitars and other electronic instruments now plug the instruments directly into the recording deck so they could be positioned anywhere.
If you do not have a method of comparing the original master recording to your hi-fi then all talk about the competence of your equipment's generation of an accurate sound stage is pure conjecture. Lots of hi-fi magazines ignore this fact and make comment about the sound stage of the equipment, that they are reviewing, with a misplaced and exaggerated authority - thus they are talking out of the back of their necks most of the time. Many hi-fi forum contributors also repeat this school boy error.
All I can say is that I have a reasonable hi-fi set up and when I play an orchestral work the instrument positions more or less sound as if they are coming from the place I would expect them to, but I would be shocked if it was exactly the same as if I had attended the actual performance. This is all I can expect of the sound stage of any hi-fi equipment and this is why we will never be able to achieve absolute hi-fi reproduction. You can believe of pretend otherwise if you wish.
