Interesting point about pyschoacoustics! I've never haad someone comment that a real piano sounded fake, they will say a real piano sounds bad, but not fake. While a virtual instrument (whenever you mention it was a virtual instrument), is discussed in terms of real or fake rather than good or bad. Perhaps in 20-50 years, the perception that it's not "real" will go away. I think the Steingraber transducer project is a great step in that direction!
A few other thoughts on some external factors that change how metallic sounds a piano sounds (and these are just thoughts). Certainly, there could be many internal differences which exist between what PTQ emulates and how a physical instrument sounds, but I suspect that the reasons for differences in how metallic the sound becomes as volume increases that we're discussing are less related to the PTQ engine but more in the microphone placement and other factors.
1. Microphones and microphone placement
This is a huge consideration that is often overlooked with emulated instruments, sampled instruments, and physical instruments. How near and far a microphone is, how many microphones, what array/configuration of microphones is used, how much delay compensation there is, what pickup pattern and design of microphone is used, and what fx a microphone is processed through (eq, delay, filtering) are tremendous factors in how a piano will sound in a recording. I love the fact that PTQ offers 5 microphones (but I'd love 6-10 even more for HQ rendering), which emulates--with quite acceptable accuracy--how changing microphone positions can drastically change sound. As microphones are closer to the hammers or the reflected sound from the lid, the more "harsh" or "metallic" the sound tends to be, and as microphones are placed further away, more room sound and "mellowness" are picked up rather than just the attack. This is one of the great challenges of good recording is to place microphones around a piano in a way that improves the sound the performer wants, and the same challenge exists with a virtual instrument. Sample libraries vary greatly in what microphones were used and in what configuration, and while many of the high-end libraries are sampled with excellent microphones in good positions and stereo patterns, it's nearly impossible to "move" the microphone in the mixing stage--just as it's nearly impossible to do after any recording. Different configurations like Decca trees vs XY stereo pairs totally change both how the piano is "picked up" by the microphones and also how it will play back in the sound-stage later. Decca trees (which are rarely used for solo recording but can be frequently used for piano and orchestra) are a traditional soundtrack choice for films, because directionality of the sound from a stereo pair gives an even "wall of sound" which is more dramatic, nebulous, or ethereal. Pop recordings use condenser mics close to the strings, harp, and hammers to give the sound "immediacy" and fit the piano more easily into the larger mix. Classical recordings usually use coincident or AB stereo pairs along with extra room mics, to give as much of a "you are seated in the hall" feeling to the recording as possible. You can try some of these differences out in all versions of PTQ by comparing the different "Recording" and "Player" and "Intimate" in each instrument pack, tend to extensively vary mic placement between them.
2. Recording equipment
To keep this from being as long as #1, tape delay will naturally increase metallic and "warm" sounds in any recording. Whenever recording anything with metal strings (guitar, violin, piano, etc.), magnetic tape--as it's redubbed or transferred in the 1960s through 1980s recording processes--will add a light, scratchy warmth to the recording, which is usually considered desirable for most genres. This is caused by surface of the tape being complex--like photography film--and resulting in slight increases and decreases in the speed at which the sound material is physically recorded to the tape: since there is nothing to physically, globally synchronize the recording at a microscopic level, you get slight artifacts that are perceived as a "warmer" sound. The Horowitz video was recorded with tape mechanisms of the time, which will change the sound--even if slightly. Add to that, video compression and encoding (and transfer from whatever media it was originally on before upload), and the sound we hear (not even including our different speakers, headphones, DACs, etc.) will have been modified significantly from what it would have sounded like to Horowitz on the stage or the audience in the hall.
3. The player
The soloist, and by extension the physical keyboard that is mechanically or digitally transferring the player's motion into data or hammer strikes, makes the greatest difference of all in how something sounds--both at the piano and in the hall. Horowitz was without doubt an incredible pianist, but his technique deserves special attention in this discussion. The "flat finger" technique he is using, is a hallmark of the Old Russian School, where the pad of the finger is used to strike the key and the finger rotates using the metacarpophalangeal joints, allowing for a softer sound and easier legato effect, whereas most Western European schools (especially the German School) favored bending the flexers of interphalangeal joints nearly vertical which gives a faster and more biting attack to the sound. (Though there are many other differences too.) To build power into the sound--to project music into the concert hall--Old Russian School players like him lift their arms and wrists more and use the support of the shoulders and back muscles to bring the entire hand down as a harder/heavier unit, while still striking the key with the pad of the finger (which definitely can make a metallic sound but not as metallic as when the fingers bent). By keeping the fingers flat, the sound is mellower, while still powerful and audible, but also uses less energy than what's required to maintain a similar keystrike with the fingers bent. In theory, this is much like a percussionist choosing a hard mallet or a soft mallet, which changes the attack of the sound and therefore the timbre. Horowitz' energy and ability to keep his fingers that straight is its own essay of his remarkably unique skill, when you compare him to other pianists of the same school (e.g. Browning, Cliburn, or Lhévinne). It's also important to note that how you play in a hall is very different from how you play in a practice room. When Jeffery Brown interview Van Cliburn, he asked why the lid of his piano was closed, and Cliburn responded that all he did when practicing was rehearse the fingering positions and when you played in a hall, the real work started. Why? Because the acoustics of a hall add sufficient resonance that anything that sounds good at home will turn to indiscernible mush for the audience. A good concertizing pianist will play far too loudly with notes far too far apart to compensate for that. This is another reason for the metallic sound in Horowitz: truth to tell, I think they just the mics too close to the piano for the live recording and I've suspected that for years with that particular concert (a terribly common mistake which isn't limited to pianos--Heifetz sounded completely different in the hall than on record because he sounded perfectly even in the hall but stood closer than is generally recommended to the microphone which changed the timbre of his recordings). It's also possible that they still used ribbon mics, which were put too close to the piano (which I believe was an old RCA radio trick that worked for that medium but was surpassed by better tech with small condenser omnis being the modern go-to for pianos). This is another easy one to demonstrate by taking old piano rolls and listening to them using different reverbs and PTQ presets, because you can immediately tell when it's a roll by Godowsky, Rachmaninoff, Horowitz, or Lhévinne--since most of those rolls will sound equally good in a large hall or in small studio setting, while the less experienced people creating rolls will sound best only in small environments, where pianolas were typical.
I would be very curious to find out how if the degree of metallic sound is resolved by mic placement PTQ for those who either want more or less.
- An excellent article on the challenges of mic placement for pianos: https://www.soundonsound.com/techniques/piano-recording
- An excellent resource on orchestra mic placement (though some of their links are broken like their decca tree article): https://www.dpamicrophones.com/mic-univ...-orchestra
- John Browning on the Old Russian School and Horowitz' technique: https://www.youtube.com/watch?v=Eru9FDvUfz4
- Jeffrey Brown's interview of Cliburn which has some discussions of philosophy/technique near the end: https://www.youtube.com/watch?v=d4Z1e6HWV3Y
Spotify:
https://open.spotify.com/artist/2xHiPcCsm29R12HX4eXd4JPianoteq Studio & Organteq
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