Soundstage...How to determine what's right?

Have started upgrading my system and will be trying to optimize the soundstage. A lot of reading has me thinking that I really don't have enough information and experience to get there.
Terms like "congestion, width, depth, and height" have me wondering how much is in the recording and how much is introduced by the system? Are there reference type cd's that people use to determine how their system is progressing? I so, could you help with a list of cuts with info regarding the placement of vocals, instruments and examples that contain material that is not congested?
Thanks for any help.
( Just to make it a bit easier: here's the URL for that article in Stereophile. They do a much better job of explaining the LEDR test. That disc also contains a left-right imaging test that extends beyond the speakers which a great many systems can't reproduce.
Thanks again. The link is helpful and the article gives a good intro to the disc. Will start with just one of the disc and see how far I get.
What about congestion? Over the last couple of days I have listened to more music than normal and heard some things that were a bit confusing. On some cd's I could place instruments and vocals front to back easily. Others it seemed that all the sound was on a single plane and from left to right. My guess is this was the recording. Still other disc seemed that all the sound was from one point and it was very difficult to differentiate one instrument location fron another(congestion?). Since it may be recording related are there recommended recordings with a lot of instruments playing at the same time that will serve as a reference? If this is addressed on the already mentioned test disc then which one?
Thanks again. Really appreciate the help.
Congestion is closely linked to a lack of dynamics. Live music is highly dynamic and there are all kind of peaks that stick out and act as cues to the ears about position and detail. Our hearing suffers from an effect called "masking" (a loud sound completely masks other sounds close by in frequency). Careful musical compositions and careful arrangements and careful recording techniques can allow you to hear the most from a recording despite your hearing limitation due to "masking". Of course none of this is much good if your speakers compress the sound or your amplifier clips. Harmonic distortion from tubes can really help bring out detail in a system that is dynamically limited. Essentially there are two ways to increase the perceived strength of a note....loudness/dynamics or by adding harmonics (makes the note sound fuller without making the peak amplitude louder). Recording engineers know this all to well and tubes are often used on vocal microphones and to process drums to get a fat or fuller kick drum sound (the richness of the harmonics increases the audibility without actually making it louder and risking breaking an average speaker). Analog tape compresses dynamics very well too. Anyone who plays an electric guitar knows about tubes and this is why guitar amps use tubes and have such a rich sound.

A very good example of a good recording with no congestion is Grace Jones "Slave to the Rhythm - hot blooded Mix". You can download this from iTunes. Another good example of a live recording is George Benson Weekend in LA "On Broadway". The George Benson recording has quite realistic drums and it will only shine if your system can be cranked and yet still produce the dynamic range in the music....otherwise it will tend to sound a bit thin at lower volume levels (remember a real unamplified drum set plays up to around 115 db SPL - enough to blow up most speakers or drive them to severe distortion - so it is no wonder that most music is heavily compressed for the capability of consumer systems). In the George Benson recording the drum set is close-miked as in funk music...this gives a very dynamic short drum sound that allows you to hear the bass guitar better (less masking)....classic jazz recordings use this technique also so you can hear the double bass whilst Rock tends to bury the bass guitar under a more fuller kick drum sound (rock being the more compressed or "congested" genre).

Another good example of creating a good tube full sound from a kick drum is ACDC "Back in Black" - this is very different from the George Benson recording mentioned above. ACDC Back in Black works extremely well on dynamically limited systems (car, most home stereo) as it has just enough compression to give it a nice punchy sound without stressing most systems.

I expect you can download all three tracks from iTunes and compare...contrary to popular audiophile belief you will not lose too much audio quality from an AAC 128 KBPS file. The tracks will still sound impressive and depending on which recording sounds best you will have an idea of the capability of your system...congested or not!

Anyway - it helps to understand how your hearing works and the recording techniques being used when evaluating a system. A system that consistently brings out new emphasis in one particuar area (compared to other systems) does NOT necessarily make it more resolving and it is NOT necessarily a good thing (no matter how pleasing). Look for clarity or increased distinction BETWEEN recordings....a system that shows greater the differences BETWEEN various recording techniques and instruments is likely a more resolving system. In this sense you are able to distinguish what the system does without being heavily influenced by an individual recording or "test CD", as unfortunately you can almost always find a track/CD that you prefer the sound of on a particular system...even ACDC may sound its best on your crap factory standard car speakers. This is why aiming for the most pleasing sound on a test CD is a bit of a minefield...a wide collection of diverse music is probably best.
Here is a link that which explains what audio engineers do to drums

Is it any wonder that so very few recordings sound realistic and like live music?

If you want something that sounds like live music with excellent soundstage (if your system can handle it - note the warning about drum transients in the link above) then try the Sheffield Labs Drum Track test CD. If you have trouble convincing yourself that there is a real drum kit in the room then your system has "congestion" and the depth of your soudstage will be limited to a more laid back or more distant presentation (not necessarily bad as many people enjoy listening to classical concerts from the first balcony - a less intense or dynamic sound than front row center).
There are a wide variety of mic technics in use by engineers that yield just as many variations in sound stage reproduction. The quality of the pressing or burning is also a factor. I bought a Columbia CD of 'Amused to Death' by Roger Waters based on the effects that were on the one my son has. The sound stage produced on our systems extended solidly from at least 90 degrees to the left or right of our listening positions and many feet back of the speakers. The disc that I bought had none of the sound stage or dynamics that his did(absolutely no depth/everything between the speakers). Same label, same title, same bar code. That much variation between otherwise identical discs(yes- we A/B'd them on both systems). I returned it!! By utilizing a test CD you are using an established "constant" or "standard" that has been measured and your system can be compared to/graded by/adjusted or tweeked according to. How can using any recording of an event that you did not personally attend give you ANY indication AT ALL if your system is faithfully reproducing the original venue? I'm assuming that faithful reproduction of the musical info on your source material is your goal. I tend to trust the experts when I choose a standard, hense my collection of Stereophile/Chesky/Sheffield Labs/etc. test CDs and pressings. Funny thing: how well my system performs with all of them, as well as the recordings I've been personally involved with. The only "minefield" is trying to find labels that are conscientious about their recording/manufacturing processes, and record the jazz and blues I enjoy. Oh- Try 'Dead Can Dance-Into the Labyrinth', recorded 4 track/A/D, in a huge(The Quivvy) church. Huge sound stage/natural reverb effects. Very strange music(new Zealand/Irish flavored).