Interesting streaming listening comparison of a few different microphone setups allowing one to listen to the way they capture stereo ambience at Helmut Wittek's Hauptmikrofon website, here-
http://www.hauptmikrofon.de/audio/stereoambience.htmlGranted none of the samples are of music, but they do provide a useful basic comparison for hearing the differences between X/Y coincident, two near-spaced setups (ORTF and
improved-PAS-like), and a spaced omni configuration.
I'm posting the link here because I find I personally prefer the setup labeled "quasi-ORTF" for all samples there except the construction site, and that "quasi-ORTF" setup closely resembles a typical "Improved-PAS" configuration (40cm / 40 degrees) with the microphones angled only 20 degrees away from center - which is a pretty typical PAS angle from the taper section or soundboard area further back in the room. Only on the construction site sample did I prefer the ORTF sample for it's more distinct left/right imaging width. For all the other samples I felt the quasi-ORTF samples produced a better balance between sharp imaging (X/Y furthest to that extreme) and natural sounding diffuse ambient openness (spaced omnis furthest to that extreme).
A few comments-
I was listening on headphones.
There is no right or wrong choice here, only personal preference.
I like the improved-PAS-like quasi-ORTF samples here because of their stereo qualities - that is to say, how they reproduce the sound, even though it is not actually being leveraged for the reasons we'd choose PAS! It just sounds better to me than the other samples. Where as the primary purpose for choosing PAS is to either simplify setup, or maximize the direct/reverberant ratio as much as possible. It's very encouraging that it also simply sounds better and more natural to me when in a prefered recording location without the ease of setup constraint.
I like to angle spaced omnis apart from each other rather than pointing parallel to each other, especially if that pair is the only mics I'm using. That provides some additional level difference information at high frequencies which makes the imaging somewhat less washy and more distinct. I think that would improve the spaced omni samples here, but the way its been done here more clearly represents the basic differences between setups without that kind of modification.
I wish there was a way to play both the spaced omnis and X/Y samples simultaneously. I like that setup for live music recording because it sort of gets the best of both worlds. There was a sample player page at the Schoeps website at one point (may still be up) which allowed similar samples to be played singly or simultaneously. I don't think it was intended for simultaneous playback of more than one sample at a time but it worked. It was very interesting hearing the difference between each setup on its own as well as combinations of two setups, as in a four microphone configuration. It helped confirm my suspected preference for X/Y + spaced omnis over near-spaced + spaced omnis, and over all of the two mic configurations alone. Best of both worlds from a harmonious combination.