I think you are correct when you say that "ambient cues" in the recording will always combine somewhat with those in a listening room. However, after reading your post and thinking about it, I still think that the equipment, specifically the speakers, will have an even greater effect.
Learsfool You may be right about this. Now that I am giving it more thought, it does seem that some speaker designs are considerably better than others at creating the illusion that you are there. So why dont we just say that BOTH the listening room and the equipment are important factors in creating the illusion that you are there, though neither is as important as the recording. Or we could leave that last bit out, and just say that ALL THREE are important. Thats probably the most realistic view, in light of the fact that their relative importance is likely to vary from recording to recording, listening room to listening room, and equipment to equipment. That whole topic is a lot like the Which is more important: Source or Speaker? threads that pop up from time to time. Talk about an infinite staircase. So, moving on to speaker design
...some speaker types will lessen the "ambient cues" of the listening room, such as horn speakers. This is actually another reason why many musicians prefer them when they hear them - the shape of the horn itself helps direct the sound more where you want it to go, minimizing some (of course not all) of the effects of the room in which they are placed. Therefore, one can hear more of the "ambient cues" on the recording as opposed to those of the room. This directness of horn speakers also tends to more closely approximate the "you are there" effect
It is certainly true that highly directional speakers minimize the ambient cues of the room and maximize the ambient cues of the recording. But I am skeptical that highly directional speakers are inherently more likely to create the illusion that you are there. In order to explain my skepticism, I have to say a few things about sound DIRECTIONALITY
A sound may be unidirectional, bidirectional, multidirectional, or omnidirectional, depending upon the number of sources, the nature of the acoustical environment, and the position of the listener. In reality, there is something like a continuum of sound directionality with unidirectional at one end and omnidirectional at the other.
In most interior spaces, ambient cues are typically OMNIDIRECTIONAL, i.e. they arrive from all directions. Likewise, in most recording spaces that are not acoustically inert, ambient cues are typically omnidirectional. That is NOT to say that ambient cues are EQUAL IN ALL DIRECTIONS. It is only to say that they ARRIVE FROM ALL DIRECTIONS (at the microphone). This fact bears directly on how to create the illusion that you are there, as I will now try to show...
As I mentioned in my previous post, creating the illusion that you are there is achieved by creating a playback space that is as similar as possible to the recording space. There are two approaches to this. The first approach is to construct a listening space whose ambient cues resemble the ambient cues of the recording space. The second approach is to construct a listening space whose ambient cues are minimal. Both approaches have liabilities, but it is the liabilities of the second approach that are relevant at the moment, for the following reason:
To the extent that you minimize the ambient cues of the listening space, the sound arriving at the listener will not be OMNIDIRECTIONAL. It will be BIDIRECTIONAL, assuming you are listening in stereo. Even if the recording has OMNIDIRECTIONAL ambient cues, what you will hear at the listening position is the BIDIRECTIONAL presentation of OMNIDIRECTIONAL ambient cues.
In other words, by minimizing the ambient cues of the listening room, the sound will arrive at the listening position primarily from TWO directions (the locations of the speakers). This means the ambient cues of the recording will, likewise, arrive primarily from TWO directions. But in the recording space, the ambient cues arrived from EVERY direction. That difference is the fundamental limitation in the approach of minimizing the ambient cues of the listening room when trying to create the illusion that "you are there." Hence...
(1) The BIDIRECTIONAL arrival of OMNIDIRECTIONAL ambient cues cannot create the illusion that "you are there."
In contrast...
(2) The OMNIDIRECTIONAL arrival of OMNIDIRECTIONAL ambient cues can create the illusion that you are there.
RE: (1). This is why headphones and anechoic chambers cannot create the illusion that you are there. Both headphones and anechoic chambers create a BIDIRECTIONAL presentation of ambient cues. But the ambient cues in an acoustically significant recording space did not arrive from only two directions. They arrived from every direction. This difference in directionality between an acoustically inert listening space and an acoustically significant recording space is an insuperable obstacle to creating the illusion that you are there.
RE: (2). This is why an acoustically reactive listening room is a critical element in creating the illusion that you are there. The acoustically reactive listening room creates an acoustical space in which the ambient cues of the recording can be presented omnidirectionally, JUST AS THEY WERE IN THE RECORDING SPACE. If, on the other hand, your listening room is acoustically inert, you reduce the possibility that the ambient cues from the recording can arrive from all directions. And if the ambient cues of the recording do not arrive from all directions, your playback space will be fundamentally different from the recording space, which destroys the illusion that "you are there."
Incidentally, this also explains negative reactions to recording studios that briefly appeared with a live end and dead end. In that design, one side of the listening room has an abundance of ambient cues, while the other side has virtually no ambient cues. That creates a more or less HEMISPHERICAL presentation of OMNIDIRECTIONAL ambient cues, which is not at all like the experience that you are there. Not surprisingly, this recording studio design was unpopular with recording engineers.
This brings me to why I am skeptical about your view that highly directional loudspeakers are inherently superior to, say, omnidirectional loudspeakers when trying to create the illusion that you are there. If you were to place highly directional speakers in an acoustically inert listening room, for example, you would create a highly BIDIRECTIONAL presentation. That means whatever ambient cues are in the recording will not arrive at the listening position from all directions, as they should. In fact, if you went far enough with this approach, you would approximate the sound of headphones and anechoic chambers, which is not at all the sound that you are there, as you point out. So if the listening room is acoustically inert, highly directional speakers are probably NOT the best choice.
Finally, I hope all this clears up the puzzlement you expressed when you said:
the only thing I would actually strongly disagree with was something you said at the end, that headphones are great for hearing the ambient cues - in fact I would say just the opposite. To me, listening on headphones, no matter how high their quality, sounds nothing like live music; nor does the presentation resemble a real space in any way, shape, or form.
Headphones are great for hearing the ambient cues IN THE RECORDING, but terrible for hearing the ambient cues AS THEY SOUNDED IN THE RECORDING SPACE, because in the recording space, the ambient cues were omnidirectional, whereas in headphones, they are bidirectional. In other words, I agree with your comment that the sound of headphones does not resemble a real space in any way, shape, or form. But the reason is NOT because headphones fail to provide the ambient cues of the recording space. The reason is because headphones fail to present the CORRECT DIRECTIONALITY of the ambient cues of the recording space. With headphones, you are hearing the BIDIRECTIONAL presentation of OMNIDIRECTIONAL information. But in the recording space, you would hear an OMNIDIRECTIONAL presentation of OMNIDIRECTIONAL information. That is what the real world sounds like. And that is what we must make our playback space sound like, if we want to create the illusion that we are there.