What audio system do you have, or plan on getting?

[StudioGuy]

So approximately what you're saying is that even the most "live"-sounding recording involved a lot of llusion in its creation in the mixing & mastering process.  To that I say no doubt but anyway the best contemporary recordings are far ahead in terms of the "live" illusion that what was produced a few decades ago.

Stereo is itself an illusion (the stereophonic effect), so by definition even the most "live-sounding [stereo] recording" must involve illusion. Whether there was "a lot of illusion" depends on genre (classical music uses a lot less than popular genres), what you consider "a lot" to be and exactly how it's recorded, particularly in the case of classical music, and how it's mixed. Mastering has relatively little effect, it's mainly down to the recording, editing and mixing. Mastering is effectively just "tweaking" the final mix, in order to make the final mix sound as good as possible on the target audiences' playback equipment rather than only on the mix studio's playback chain. Modern recordings sounding more "live" is a consequence of several factors but is largely due to more options and "trickery" rather than less.

I have a few CD versions of the Mercury Living Presence records created by Bob & Wilma Cozart Fine.  The CD versions were remastered for the media by Wilma herself, (not so the SACD versions as I've heard).  These recordings seem good in comparison to other early recordings -- much better in terms of "liveness" than, e.g., Deutsche Grammophon recordings made in that era and quite awhile thereafter.

The fifties was a very interesting time in recording history. Technology invented during the war was further developed for commercial use and the release of stereo introduced a whole slew of recording considerations, the combination of which resulted in a wild flurry of recording experimentation, development and competition. Arguably leading the way was Decca but with the possible exception of EMI, each had some talented engineers/producers producing some excellent recordings although some were slightly ahead of others. ...

(My comment once was they they sounded like they were made in a high school gymnasium...OK that's a bit hyperbolic.)
Apparently most of those Mercury recordings employed a minimal microphone technique, i.e. only three mics.  But I'm told that that sort of minimal microphoning requires an inherently excellent recording venue and careful placement of the musicians as wall as the mics.

OK, this is where we get to the heart of the matter (particularly with classical music recordings) and unfortunately it's also very complex due to the technical/acoustic issues, the subjective/psychoacoustic issues and the relationship between them. On the technical side we've got acoustic issues such as the "inverse square law", Sabine's formulas, Schroeder frequencies, critical distance, microphone polar patterns and freq response, et al. Far too much to go into here but some salient simplifications; the closer the mic/s is to the sound source the more of the direct sound from that source is captured relative to everything else, specifically extraneous noise and room reflections/reverb and of course vice versa when the mic is placed further away. Using a few mics when recording a relatively large ensemble therefore raises the issue of recording a balanced sound, while at the same time accounting for the "critical distance" (the distance at which the reflected sound is equal in level to the direct sound). This requires a considerable amount of time/experimentation and often, the optimal distance for a balanced sound is not the optimal distance relative to the critical distance, so the engineers/producer had to compromise. This is almost certainly the cause of the "gymnasium" effect you described.

In addition to the above are the psychoacoustic effects and specifically the "cocktail party effect" ("selective hearing"); at a live event, what we see and hear informs/allows our brains to "focus" on specific sounds by reducing everything else. In a reverberant and/or noisy environment, we will perceive more of the salient sound due our brain reducing the amount of perceived reverb and noise. In other words, if for example we placed microphones at a particular listening position in the auditorium, it will record more noise and reverb than a human in that same location would perceive/experience. So, we would have to employ some "trickery" to alter the sonic reality to more closely match the "experience".

The solution to many of these issues is to use more (multiple) mics, although that brings other (more minor) issues, particularly in the 1950's when only 2 or 3 channel tape recorders were available. Decca largely pioneered this approach, developing the 3 mic Decca Tree in the early '50s, adding "outrigger mics" in the mid '50s and then 4 or more "spot mics" in the later '50s, despite the minor issue of requiring more "trickery". By the late '60s their orchestral setup was around 30 mics and all the other labels followed the same multi-mic course, with the only exceptions being one or two minor audiophile labels who managed to convince their gullible target audience that using just a couple of mics was somehow purer/more authentic and therefore "better", when the reality was that it was inferior.

As I'm given to understand, many DGG recordings were remastered for CD using their "Original Image Bit Processing" method which involved remixing the numerous original tape tracks with subtle time delays to simulate a more concert hall ambiance.

No, DGG may have added reverb or "subtle time delays" to some of their recorded tracks and indeed that is generally required when recording a large ensemble with a main array and spot mics but that was incidental to their "Original Image Bit Processing" method. In the 1990's studio digital recorders evolved to 20bit recorders (and then to 24bit) but the distribution was still CD and therefore it was necessary to reduce the bit depth to 16bit for distribution, which required the use of dither. After the publication of the Noise-Shaped Dither Theorem, companies started to produce products that employed that process, initially Sony with their "Super Bit Mapping", Apogee's "UV22" and others followed. The labels then started using their own marketing and marketing slogans for this, this is what DG's "Original Image Bit Processing" is, along with HDCD (high definition cd) and various others but all of them are just noise-shaped dither, which is inaudible at any reasonable listening level and way below the noise floor of old analogue recordings.

[Fëanor]

As I'm given to understand, many DGG recordings were remastered for CD using their "Original Image Bit Processing" method which involved remixing the numerous original tape tracks with subtle time delays to simulate a more concert hall ambiance.

No, DGG may have added reverb or "subtle time delays" to some of their recorded tracks and indeed that is generally required when recording a large ensemble with a main array and spot mics but that was incidental to their "Original Image Bit Processing" method. In the 1990's studio digital recorders evolved to 20bit recorders (and then to 24bit) but the distribution was still CD and therefore it was necessary to reduce the bit depth to 16bit for distribution, which required the use of dither. After the publication of the Noise-Shaped Dither Theorem, companies started to produce products that employed that process, initially Sony with their "Super Bit Mapping", Apogee's "U22" and others followed. The labels then started using their own marketing and marketing slogans for this, this is what DG's "Original Image Bit Processing" is, along with HDCD (high definition cd) and various others but all of them are just noise-shaped dither, which is inaudible at any reasonable listening level and way below the noise floor of old analogue recordings.

Thank you for this interesting correction & clarification.

I've heard audiophiles insist the DGG's 'Original Image Bit Process' CDs are "a big improvement over media without the process.  I have no personal opinion (or impression) since I have few 'Before' examples and those LPs.

FWIW, I have an original 1975 Carlos Kleiber Beethoven 5th LP, (to which I haven't listened in years).  I believe this was recorded on analog tape.   CD versions today claim to be Original Image Bit Processed;  presumably the tape recordings are converted at a higher bit rate and down converted to 16/44.1 with the advanced dithering process.

I also have the Klieber performance on SACD;  I generally listen to the ripped stereo CD layer of the SACD.  If I can find the disc I might have a listen to the SACD layer on my Sony Blu-Ray with outputs 5.1 channel in PCM format.

As for the Kleiber performance, I seems almost OVERLY dramatic, something that would probably have surprised Beethoven himself ... but I'm not a musician or any sort of musical expert, so what do I know? 

[71 dB]

No, DGG may have added reverb or "subtle time delays" to some of their recorded tracks and indeed that is generally required when recording a large ensemble with a main array and spot mics but that was incidental to their "Original Image Bit Processing" method. In the 1990's studio digital recorders evolved to 20bit recorders (and then to 24bit) but the distribution was still CD and therefore it was necessary to reduce the bit depth to 16bit for distribution, which required the use of dither. After the publication of the Noise-Shaped Dither Theorem, companies started to produce products that employed that process, initially Sony with their "Super Bit Mapping", Apogee's "U22" and others followed. The labels then started using their own marketing and marketing slogans for this, this is what DG's "Original Image Bit Processing" is, along with HDCD (high definition cd) and various others but all of them are just noise-shaped dither, which is inaudible at any reasonable listening level and way below the noise floor of old analogue recordings.

That's what I thought "Original Image Bit Processing" was, basically shaped dithering, but I wasn't 100 % sure. The way these companies describe these methods to us customers is marketing nonsense, not exact technical description. 

[Todd]

By the late '60s their orchestral setup was around 30 mics and all the other labels followed the same multi-mic course, with the only exceptions being one or two minor audiophile labels who managed to convince their gullible target audience that using just a couple of mics was somehow purer/more authentic and therefore "better", when the reality was that it was inferior.

Like Water Lily Acoustics.  Back in the 90s, a local iconoclastic stereo dealer didn't buy the marketing nonsense and did a demo of one of their recordings and a Decca recording to prove the point.  His advice was to ignore audiophile claims, which seems counterintuitive.  That dealer is still around, unlike most others from the time.

[StudioGuy]

Thank you for this interesting correction & clarification.

You're welcome!

I've heard audiophiles insist the DGG's 'Original Image Bit Process' CDs are "a big improvement over media without the process.  I have no personal opinion (or impression) since I have few 'Before' examples and those LPs.

FWIW, I have an original 1975 Carlos Kleiber Beethoven 5th LP, (to which I haven't listened in years).  I believe this was recorded on analog tape.  CD versions today claim to be Original Image Bit Processed;  presumably the tape recordings are converted at a higher bit rate and down converted to 16/44.1 with the advanced dithering process.

It's entirely possible, in fact expected that the "Original image bit process" CDs are a big improvement but not because of that process, just because it was remastered and then distributed digitally. Media without that noise-shaped dither process (EG. Just with standard TDPF dither) would be audibly indistinguishable. Consider that the noise floor of studio tape recorders in the '50s was at around -50 to -55dB, by the mid '70s that was down to around -68dB and at their peak in the 1980's, down to around -70dB to -74dB. CD using standard dither has a noise floor around -92dB and with noise-shaped dither around -120dB (in the critical hearing band). So that's dither noise that's about 16 times and 316 times respectively below the noise floor of the tape they're recording from and therefore in both cases completely inaudible.

As for the Kleiber performance, I seems almost OVERLY dramatic, something that would probably have surprised Beethoven himself ... but I'm not a musician or any sort of musical expert, so what do I know? 

Interesting question. There's no way to know of course and I would guess similarly to you but even if he were surprised, I think he would have been supportive, especially given the context. Beethoven obviously knew his 5th would be surprising, if not shocking and reports suggest he may have deliberately emphasised that fact. Holding the baton raised for several minutes until the audience was silent, to increase the impact of the opening phrase, baring in mind that prior symphonies (by say Haydn or Mozart) tended to start quiet and build to a climax. So Kleiber being overly dramatic is arguably more true to Beethoven's intention and the experience of concert goers of the time, given today's context where it's such a standard of the repertoire that it's no longer surprising/shocking.

Like Water Lily Acoustics.  Back in the 90s, a local iconoclastic stereo dealer didn't buy the marketing nonsense and did a demo of one of their recordings and a Decca recording to prove the point.  His advice was to ignore audiophile claims, which seems counterintuitive.  That dealer is still around, unlike most others from the time.

Actually I don't recall hearing of Water Lily Acoustics, I was thinking more of Sheffield Labs but I know there were a few others over the years and reading up on them, yes, exactly like Water Lily Acoustics. And, I'm glad that dealer is still around, good advice!