Sound stage as applied to headphones, and a little opinion paragraph on loudspeaker and headphone conjunction in a proper studio

A fellow on one of my audio related Facebook pages questioned me recently regarding what sound sound stage (in regards to headphones) truly is.  Thus, this question prompted me to type out this relatively long winded explanation on what I believe sound state is when represented by a headphone.  I do hope that my explanation is sufficient enough to please the audio enthusiasts, and that it is not to confusing or contradictory! Through my listening experiences with several varying types of headphones played from a vide range of headphone amplification equipment, I believe that my explanation of sound stage can be confirmed by those who have experienced it with headphones that are masterful at reproducing this sound phenomenon.

Polk Audio Monitor 60 Tower Speakers

In general terms, sound stage is how physical instruments, or electronic synths and sounds in the case of electronic music are represented by a headphone. Sound stage can be represented through the X, Y and Z axis's respectively. Think of headphones with poor sound stage as being very flat and having a more two dimensional or mono feel, as apposed to headphones with good sound stage that subsequently have a more open and three dimensional sound characteristic. In headphones it is often difficult to represent three dimensional sound because they are sitting directly on your ears. Headphones with poor sound stage are often described by audio enthusiasts as producing sound that seems to come from "inside" your head, or producing sound with very little direction. When listening to an orchestral ensemble on a pair of headphones with good soundstage, one should be able to discern each physical section of the ensemble, sometimes even the physical instruments. The sound is very spacious, and the instruments are all separated and easily picked out by the listener, while maintaining incredible clarity. Compare this to many Bose, Beats and lower end headphones and you can really tell the difference. On these types of poor sound stage headphones, the instruments tend to blend together as apposed to being separate, yet harmonious and spacious. When this principle is applied to electronic music, the bass is typically separate and distinct from the middle ranges and high ranges. Same goes throughout the frequency spectrum. High ranges are also separate and distinct from the bass. Its a very difficult headphone characteristic to explain. Its like the separation of the different aspects that make up a song, yet through this individual separation, the song is played at a higher fidelity as apposed to headphones that mold and muddy it all together. It is through this separation that the sound is reproduced better as a whole. There are other sub-aspects of sound stage if you will, like imaging. Imaging is whats placed within the sound stage. Here you should be able to pick up the individual characteristics of the said instrument, its size in relation to the others in the sound stage. ie a piano should sound much larger than a violin etc. Hope my explanation made sense instead of just confusing you all!

Sennheiser HD 280 Pros

Further more, I just wanted to add in a little bit more about sound stage except this time in regards to speakers.  It is true that speakers do produce sound stage more readily, and arguably better than headphones.  They are also able to do this even from mediocre or entry level speakers.  My current audio setup in my room consists of two Polk Audio Monitor 60 tower speakers, and a Polk Audio PSW-10 subwoofer (effectively a 2.1 setup).  Even through this admittedly entry level set up, sound stage is more readily apparent as apposed to my Sony MDR-XB700's, Sony MDR-7506's, and Sennheiser HD 280 Pro headphones.  However, the reason studio monitor headphones (like the 7506's and HD 280 Pro's) are used in studios is because they are able to reveal minute details that even the highest end speakers cannot.  A proper studio consists of studio monitor loud speakers in which to check and evaluate the sound stage of a given recording, and reveal any major and apparent flaws in the recording.  The recording is then combed over with the studio monitor headphones, revealing any small recording flaws.  The reason studio monitor headphones are used in conjunction with studio monitor loud speakers is because of the inherent flaws in any loudspeaker.  These flaws include speaker crossover issues, sound reflections and nulls.  Also the physical frequency range of the speaker driver itself is an inherent issue.  In higher end studio monitor loud speakers, these issues are subdued, but never eliminated completely.  Studio monitor speakers and headphones go hand in hand.  The idea that only one is needed without the other is truly blasphemous in my opinion.  Coming back to the sole original purpose of this now fairly long add-on, yes loud speakers are generally better at producing a more accurate representation of sound stage as apposed to headphones.  If you think about the different characteristics between headphones and loud speakers, it makes quite a bit of sense.  However each has its own redeeming qualities which in any case still forces me to use both, headphone and speaker.