Is it possible to really know what you're doing?

I agree that a reference / standard needs to be established.  Former dictionary such as Oxford English Dictionary (OED) defines a stereo(phonic) system as a system of sound recording or reproduction using two or more separate channels to produce a more realistic effect by capturing the spatial dimensions of a performance.  So, imho, two keys elements defines a reference stereo system:

1. Realistic effect; and

2. Spatial dimensions.

In my pursuit of a reference audio system, I aim to achieve a setup that faithfully reproduces the tonal character (timbre) of instruments and voices with a high degree of accuracy.  This includes precise imaging—where each sound source is rendered with a clear, stable, and locational presence within the soundstage.  So, I were to lay out a specific metric for the reference system including:

1. Timbre accuracy;

2. Imaging; and

3. SS width, depth and height.

This metric may not be measurable instrumentally, but it can certainly be perceived in your listening space with a good pair of ears and a discerning mind. I believe you could always expand this metric to include many more elements you consider paramount. But bear with me for being simple-minded—and tell me, are you there yet?

@richardbrand 

I do concur that the standard or reference should be the live performance. However, if a stereo system can reproduce even better sonic quality or effects w/o artificial / overdone sweetening, I consider it a bonus rather than something unnatural. The reason is as follows:

In a concert hall, the sonic quality perceived by you and me is heavily dependent on the acoustic treatment and where you sit. Whether your experience is excellent or just so-so is subjective and can vary greatly due to these factors, making it difficult to use as a reliable reference for live concert sound. I am located in Palm Beach County, FL, and the concert hall I’ve attended is the Kravis Center in the City of West Palm Beach. Although the seating is very spacious and comfortable, I’ve always felt the acoustics leave something to be desired.  One time, we went to Miami New World Center, a relatively new concert hall (open in 2011) designed by renown architect Frank Gehry (designer of Guggenheim Museum Bilbao in Spain).  That time, we were in less preferable sitting area but the sonic effect we had perceived is well better, closer to if not outperforming the experience we had in Berliner Philharmonie, home to the Berlin Philharimonic Orchestra.

Through proper recording techniques using multiple microphone placements and careful mixing, a live concert performance can be recreated more faithfully—without undue influence from the concert hall’s acoustics or the listener’s seating position.

I believe a heat map, like the one shown below, is one of the best ways to illustrate sound source imaging and spatial cues within the soundstage. More pin-pointed sources (such as a solo instrument) are represented by smaller contours with concentrated peaks, while larger, fuzzier contours with less dense peaks represent sections of grouped instruments in an orchestra. The deep blue areas indicate the dark background between sources, highlighting instrument separation.  Of course, the contour represents the depth of the soundstage.

Even the larger, fuzzier contours still retain their locational presence. I often cross-check whether the spatial positioning of instruments or vocals I perceive from the recording or stereo system aligns with the actual layout of performers on stage—when video or images are available. With a well-produced recording, the answer is often yes.

Grammy-nominated recordings typically reflect the highest standards of recording engineering and fidelity.  In Grammy-nominated or Grammy-winning recordings, the recording engineering approach is almost always multi-microphone technique, not One Mic.  Multi-mic tech. enables precise control over indi. instruments, vocals, room acoustics, direct sound, image, SS depth, etc. We are talking about reference / standard here in lieu of something based on someone's ad hoc opinion.

@richardbrand  I agree that Time Machine's performance is amazing. I'm not sure how Rex interpreted Grainger’s use of the foot pedals — By ear I would guess.

Thank you for reminding me about L2. I was astonished to learn how productive they've been in recent years since I last visited their website. That got me thinking again about multichannel streamers and DACs, which are still quite rare. I suppose both we and the market have been largely two-channel driven.

Now I realize that when playing these multichannel formats on a 2-channel system, the original spatial (surround) placement gets lost in translation. My 2-channel setup — and perhaps no 2-channel system — can truly reproduce that 3D effect, especially the instruments or vocals that are originally placed behind the listener. Even my soundstage isn’t wide enough to fully cover side vocals. Clearly, a multichannel system is needed to reproduce that experience accurately.  That’s why I’ve never used "3D holographic" as one of my system metrics — only "depth" or "layering" — due to the inherent limitations of two-channel playback.

Are you motivated to invest a multichannel stereo or you have it already? 

So Rex Lawson did not have to interpret for the Piano Concerto, though he did for earlier rolls made by Grieg included on this recording.

@richardbrand  Thank you.  That answers my question.  Since the picture shows him playing the pedals, I was curious why pedaling could also be entirely encoded onto the rolls. I read that the Duo-Art was invented in 1913–14, and it’s amazing that the machine could even simulate ’flutter’ pedaling performed by a pianist—though only to a certain degree and heavily dependent on how the rolls were prepared or edited. It’s remarkable that it achieved all this not digitally, but purely through pneumatic control of mechanical parts.  I enjoy talking with you about these detailed nuances. While listening to music on a refined system, the intellectual enrichment is equally refreshing and rewarding.

The world of high-fidelity audio is like an ocean — beautiful, vast, and deceptively mysterious. On the surface, it might seem as simple as riding the waves: just plug in a few components and enjoy the music. But the water runs deep — diving in requires not only a wealth of knowledge but also a touch of fortune. And the deeper you go, the more you realize just how layered and complex it truly is especially in the following areas:

• Technical depth: Understanding gear specifications, DAC chip design, amplifier topologies, room acoustics, jitter, phase coherence, etc., demands a strong foundation in electronics, physics and, most relevantly, psychoacoustics.
• Subjective variability: What sounds “right” is often personal and system-dependent, requiring critical listening skills, patience, and trial and error.
• Tuning and synergy: The journey isn’t just about owning high-end gear.  It’s about components matching (could be a matter of luck), placement fine-tuning, vibration control, power supplies, cables, and even music formats.

In the world of music reproduction, you don’t just listen — you learn, test, tweak, and invest. The audio hobby is as rewarding as it is demanding. Like diving into deep water, it’s not something to approach unprepared. It requires a blend of curiosity, patience, critical thinking, and yes a measure of financial flexibility to navigate meaningfully. And no matter how deep you go, you'll never quite reach the bottom.

Oh, many folks do! And then they keep digging. 

I’d still like to know, if possible, who has claimed actually reached the bottom and what specific systems are so we could possibly use them as benchmark.  This is how we learn and grow, right?