I've read that recordings with proper stereo imaging cannot appropriately be heard with headphones. (This was a side note listed on this article...)
Is this true? If so, what is the reasoning? I was under the impression that headphones would be best for stereo imaging tests, as they are in a fixed position in relation to the listener.
The LEDR Test page also seems to imply that headphones would be appropriate for stereo imaging listening.
With headphones you get complete separation, which you don't get with speakers. Therefore the stereo imaging is different. And it can be better, if the music is made to listen in headphones, but worse if it is not.
An extreme example is Sargent Pepper. Listen to it on speakers, and then in headphones. There is no stereo field in any real sense, instead some instruments are simply in the left channel and others in the right. This sounds fine on speakers, but in headphones it can even be annoying and make your eyes water before you get used to it. It feels a bit like having water in your ear.
And the opposite is true as well. If you mix with headphones, the stereo field will seem narrow and flat when listening in speakers. So since most people listen on speakers, most music is made for speakers and the stereo imaging tend to be wrong/too wide when listening on headphones. This is not a problem for popular music, but it is the kind of thing that annoys audiophiles who listen to music not because the songs are good, but to be impressed over how well you can hear the audience noise. :)
I am not sure why this question was asked, but if you intend to do a production that is meant to be listened to specifically with headphones, there is an option on which I would like to write a general note.
You can record your stuff with a binaural microphone system (you don't have to get your hands on an artificial head, I got astonishing results when recording in the field with just a pair of headphones on my own head with a pair of DPA 4061 microphones glued onto the shells, I didn't care about front-rear distinction though.)
If you happen to have a recording already done with intensity-based stereo that sounds good on a pair of studio loudspeakers, try applying the HRTFs manually to your signal. One plug-in that does this that impressed me very much is the Wave Arts Panorama Plugin which has several HRTFs on board for different artificial heads, and even a few of real heads, and it allows you to pan the sound around your entire head, as if it was surround. The surround effect is generated by filtering the signals so that your brain thinks the filtering was done by your earshells, because the sound is coming from behind.
A general note for everybody who intends to use this technique for artificial surround: remember that ears are different. All people are expecting different filtering effects that matches their earshells. Therefore, a HRTF that works perfectly on your head might just not be the best one on other's heads. Keep this in mind while mixing, and ask multiple people to listen to your stereo/artificial surround image.
The reason is due to what is called a 'head-related transfer function', or HRTF. In particular, the attenuation of higher frequency sounds at one ear vs. the other ear and also the delay in arrival time between them. Sounds wrapping around the head, you see. With headphones directing those higher frequencies right down your ear canal(likewise, both left and right signals are heard simultaneously at their respective ear), the stereo image is sacrificed. There is also crosstalk, which I won't go into. Note that if you do 'dummy head' stereo recordings(binaural), you can only ever get the effect through headphones. Wild!