Calibrating My Ears at the San Francisco Symphony

Most of us audiophiles like to attend and experience live music, not just for the sonic treat that it is, but also as a way for us to calibrate our ears and brains - i.e. to provide a reference which we strive to approach with our audio setups.

This was the situation I found myself in San Francisco recently, on a gorgeous sunny Sunday afternoon. A business trip had brought me to the Bay area, so I seized the opportunity to go see one of my favorite orchestras, the San Francisco Symphony, led by Michael Tilson Thomas, aka MTT/SFS. Emerging from the BART, I was startled and then amused to find that my walk to the concert hall coincided with the San Francisco Pride parade. Buoyed by the bonhomie of the marchers, I found my way to Davies Hall, and my seat (in row N), which gave me this vantage point - just about the perfect spot for my tastes:

It was right  about when I took this picture that the idea occurred to me that I should use this experience to really focus on aspects of the live experience and contrast it to what I hear in my system. After all, the program was intensely familiar to me - Sibelius Symphonies 6 & 7, and Rachmaninoff Piano Concerto No. 3. This meant I could let this familiar, extremely pleasurable music wash over me, and still be able to analyze the aspects of the experience I'll describe below. 

Let me explain why this was the perfect spot for my tastes. After attending many, many performances in many concert halls sitting everywhere from the first row to the rafters, I have found that sitting close to the stage really allows you to experience the sheer power and raw physicality of a live orchestra in a gut-punching way. It's tremendously exciting, but the disadvantage is you're looking at the performers'  ankles, and you have no view of the orchestra. My preference is to be up just a few rows where you can see all the performers, although the woodwinds and the brass sections still tend to be hard to see. The location pictured above is just about right for me, as while you do give up a tiny bit of the power and punch, it's not much, and you have the benefit of a much better view and perspective . I'll come back to this when I talk abut visual cues. 

With this background, I'll spend the rest of this article on various aspects of the listening experience, and contrast this with my audio setup, or audio systems in general.

Soundstage and Imaging

Once the music began, I closed my eyes to simulate the experience in my listening room, and focused on placing instruments (or clusters) in 3-dimensional space. The degree to which I could do this spatial placement was incredible, but there were surprises too. Remember, the sound from the instruments interacts with the concert hall, creating reflections, reverberations etc. What this does is diffuse and smear the localization, so the spatial placement isn't pinpoint accurate. In a way, this is really useful to hear, because it made me realize that the imperfect sound staging I hear in my system isn't as "imperfect" as I think, since even the real thing is more diffuse, and dependent on the concert hall's acoustics.

One thing we strive for, but is hard to get right in our system, is image depth, or front to back sound staging. Here again, the degree to which I was hearing depth cues was amazing, but again - surprising, too . Sitting mid-hall as I was, I realized that while my ability to place instruments front to back was way better than any audio system, the extent of front to back was not as great as I thought, due to the foreshortening effect based on my vantage point. The soundstage wasn't "incredibly deep," it was just right for the geometry of the space, the orchestra, and my position relative to them. What this made me realize is that we sometimes go overboard in our quest for stage depth. Rather, the better quest or goal is for the depth to sound just right.

Visual Cues

Remember, until this point, I was recording my impressions with my eyes closed, because in my listening room, I do not have the benefit of being able to see the musicians playing. But at a concert, I do have this advantage, so what does it add? Wow. Try this next time you're at a concert of any kind. Experience the music with your eyes closed, and then with them open.

The extent to which visual cues enhance the experience is not just astonishing - it is mind boggling. The diffuse, imperfect placement of instruments is swept away, and the imaging is just about perfectly precise. Well duh, Captain Obvious, you say - of course it is, since you can now see where the instruments are. Yes, this is obvious, but it does underscore the fact that sight can play an incredible part in the listening experience. Whereas without sight cues, that french horn was vaguely in that corner there, my brain was now localizing it precisely, and my ears played along, as if to say "I knew it was exactly there all along!"

Going back to the listening room, I've experienced the power of visual cues myself. I subscribe to the Digital Concert, a streaming service of the Berlin Philharmonie, which streams all the BPO concerts live, as well as provides access to a vast archive of prior recordings. While this stream is relatively good quality, it is not lossless, and certainly not high-resolution. If I listen to a performance with no video, it's pleasant enough, but no match for my best recordings. But display the performance on my 100" big screen simultaneously, and it's a whole different experience. Why? The audio is the same in both cases. The addition of visual cues makes the difference.

Certainly, this is no surprise, as the whole premise of home theater is based on the same principles. Home theater components are not generally engineered to the same extremes as high-end audio gear, but we frequently speak of the home theater experience in superlatives.

I know the use of video in the listening experience is hardly an audiophile preference, but it's food for thought.

Dynamics

From the barely audible sound of an instrument playing pianissimo, to the knock-you-off-your-seat sound of the entire orchestra playing the loudest crescendo, the dynamic range of a live orchestra is something to experience! Of course, the acoustics of the hall, your listening position, even the size of the audience - these all matter. Yes, put enough human bodies in the way, and they act as an acoustic damper! 

Still, once I heard the range from the first diminuendo to the first crescendo, there was no doubt at all that this is no audio system - it's the real thing. Why is that? First is the clarity with which I could hear even the softest passages. Then came the crescendoes! These were momentarily so loud as to literally startle me. The key word here is momentarily. Obviously, sustained sound at that level of loudness would damage the hearing. But it is really that fleeting loudness, what we audiophile call transients, that stand out in a live concert.

It is extremely hard to make an audio system deliver this dynamic range. Obviously, transducers and amplifiers bear the bulk of the burden to deliver dynamics, but the digital chain can profoundly affect it too. In my own digital chain, and in my experience, the key subsystem that affects this is the power supply. This is fairly obvious in a DAC, but the power supplies' quality and robustness seems to matter further upstream as well. I have found that optimizing power supplies in the digital path pays rich dividends in dynamics. Is it close to the live experience - no, but it's getting ever-better.

Tonality

We audiophiles love to throw around adjectives like bright, dark, warm, analytical, and that's even before we get creative! I hope it's fair to say that as computer audiophiles, we are all at war with digital harshness, glaze, or etchiness, which often gets lumped under the term bright. With this in mind, I would describe the sound of a Real Concert™ as darker than most digital audio systems. What I mean by dark is the absence of any kind of brightness or glare. There is a sense of calm and ease to the sonic experience. Traditionally shrill instruments like piccolos, oboes, trumpets and trombones don't grate on your ears. Except when they're meant to. 

The other aspect of a live concert is bass. Deep, glorious, gut-punching, ball-busting bass. Most non-classical listeners have a misconception of classical music as polite elevator musak. People in formal clothes sipping wine, and clapping politely. The reality could not be more different. Classical music can be beautiful, yes, but also ugly, visceral, and raw. And deep bass - the growl of the double basses, the blat of the tuba, and the thump of the tympani - is a vital element of that experience.

One instrument that seems to be particularly difficult to reproduce correctly is, of course, the piano. As I listened to Daniil Trifonov's beautiful playing of the Rachmaninoff, I realized there is something about a live piano's tonality and dynamics that is immediately recognizable, even with eyes closed.

In the context of my own system, I could tell I still had quite a way to go to achieve this level of tonality. While my system reproduces piano notes without obvious harshness or color, it's just not the same. Still, what heartened me is that the trajectory I was on, the optimizations I was making, were all pulling me in the right direction.

Timbre

One of the most satisfying aspects of a live concert experience is savoring the sound of instruments in all their nuance and complexity. Listening to instruments live is to hear an overwhelming wealth of minute details - the intakes of breath, the creak of chairs and instruments, the sound of fingers plucking strings, the sound of mallets striking tympani, the sound of a piano's hammers hitting the strings. Instruments have a spatial volume - a size in 3 dimensions. We often use the term dimension to describe this. Massed instruments playing in unison, especially strings, sound like a collection of individual instruments, not like one giant amalgam. Even when playing the same note, the thin reediness of an oboe is profoundly different than the rounder tone of a clarinet. When evaluating this characteristic in our systems, people tend to use terms like texture, dimension, and resolution.  

I want to mention voices and song in this section. Although this particular concert did not involve vocalists or a choir, this is another area where experiencing the human voice in song - live - delivers the kind of goosebumps no recording or audio system can. Massed voices - as in a choir - are another example of the timbral richness of a live experience. Listen hard enough and you can make out the individual voices that comprise the whole. Or sit back and soak in the magnificent collection as a whole.

It was humbling to hear how far from real my own system was. This (timbre and texture) is an area that is particularly benefited by the optimizations in the digital chain from the DAC on upstream. Improvements to clocking and power supplies, for example, seem to reveal timbral subtleties as their reward. Again, this has been an area of focus for me. When I compare where I started a couple years ago to where I am, my system has loads more timbral accuracy. Yet, compared to the real thing, there is much more to be done.

Summing up

One would have to be a deluded fool to think that one's audio system could reproduce music as well as it sounds at a live performance. I'm not a deluded fool. I use these experiences to cast a critical eye at my system, and identify which aspects are weakest, so I can prioritize what to optimize, when I am able.  One would think that this exercise would be a depressing one, but perhaps surprisingly, I don't find this to be the case.
 

I am pleasantly surprised at how enjoyable a listening experience we now have the ability to create in our own homes. Especially in the context of digital and computer audio, the extent to which we can now approach the tonality, timbre, and soundstage of live music is incredible, and improving rapidly. Of course, this is nowhere close to the "real thing." But enjoyable, uplifting, even soul-touching? Absolutely.