So to me the question wouldn't be "are we SUPPOSED to hear individual violins in the recording of the orchestra" but rather "does the recording itself CONTAIN resolution of such detail?" And if it does, can our speakers reproduce that sonic detail for us to hear? Or is it possible to have recordings that encode detail
so subtle that it can not be transduced in to sound via current speaker designs? (And, again, we can separate that question in to 1. Can a speaker transduce that content?" vs "and if so, is it below the practical limits of our hearing" so one can also speak to our hearing limitations).
Do you hear individual violins when you listen to an orchestra live (the assumption is it is a good orchestra). Answer: No, unless the conductor intends for you to hear an individual one (violin concerto), or there is one really bad violinist out of tune or tempo, or one that is audibly louder than the others. Let’s assume with our hypothetical orchestra, they perform like a well oiled machine . The concert master and other 9 violinists are in perfect unison and they sound as one and so audience members regardless of hearing level or skill can’t hear individual violinists.
Are we supposed to hear individual violinists in a recording of the orchestra?
Fortunately, that has a very easy and simple answer. It depends on how the orchestra was recorded. Then it depends on how the recording was mixed and what format - for sake of argument and simplicity, let’s say it end up being a 2 track stereo in digital format.
I can record that orchestra with 2, 3, 4, 6, or 8 microphones (ensemble setup) across the front, at a single height, or dual heights. At an absolute minimum, it will record everything capable of being perceived by human hearing. Every instrument in the orchestra, the conductor’s baton tapping, the toes tapping of the double bass player, the AC system, a train horn in the distance, a bad hammer on the piano, etc. Or I can use an ensemble set up (8 microphones as an example) augmented with each violin (let’s say 10) in the orchestra individually miked. Again, everything that is capable of being heard, will be on that recording, Eight tracks of the orchestra as a whole, and ten tracks of ten individual violins.
Again, with professional grade microphones, proper placement, professional grade digital recorder, all of the information capable of being heard by the human ear (and much more) will be on that recording.
It can be mixed however you want it to sound. If you don’t want individual violinists, it can be mixed that way. Want the violin section as a whole to come up or down, easy. Want the cellos up or down, easy. You want the toe taps, no problem. Because the violinists were tracked individually, if you want them where they were on stage, that’s easy. If you want 4 on the left, 4 on the right, and 2 in the center, that’s easy. If you want any of the violinists to stand out a little more than the others, easy.
Is there a 22.7 hz hum from the HVAC equipment that’s audible in there, poof it’s gone.
The problem, going all the way back to tape, isn’t that the recording isn’t capturing enough “content” or information (detail), it’s that it captures too much information (noise). It’s been that way for at least 75 years.
Is a speaker capable of reproducing/transducing that content? If the speaker system has a relatively flat frequency response that covers the range of frequencies of the content (recording) then it is capable of reproducing (transiting it).
Is it audible, below the limits of our hearing? It depends on how it is mixed. If the piano is at the level that someone in audience would be hearing it live, and you know what you are hearing, the bad hammer will be there. If the toe tapping of the double bass players is 20 Fb below the overall level of the performance and wasn’t emphasized or de-emphasized in the mix, probably not, but it’s there on play back. Some may hear HVAC hum on play back, others not.
The information/content is on the recording, with a capable speaker, it’s also on the playback.