PASHKULI irrefutable?
I think there’s a mixture here of some good recording practice and quite a lot of cargo-cult engineering.
A good room: yes.
Experiment with mic placement and actually record test passages: absolutely.
Check the complete dynamic range and listen carefully for phase/comb-filter problems when combining multiple mics: yes.
But I don’t understand why the rest follows.
A grand piano isn’t four loudspeakers called bass, mid, upper-mid and treble. The strings excite bridges and a very large soundboard, and the radiation pattern is extremely complicated and frequency dependent. One of the reasons a grand sounds like a grand piano at some distance is that all of this integrates acoustically.
So starting with four close microphones and reconstructing the piano afterwards seems rather backwards if the objective is a natural piano recording.
Likewise, why is removing the lid automatically correct? The lid is part of the acoustic design of a grand and changes its radiation into the room. You can absolutely record lid-off if that’s the sound you’re after, but it isn’t some objectively superior configuration.
The bit I disagree with most is “phase align” the six microphones.
Phase-align them to what, exactly?
You have a physically huge source, different strings in different locations, a vibrating soundboard, four close microphones, two distant microphones and hundreds of frequencies. You can time-align the arrival from one chosen location or transient. That doesn’t somehow phase-align the entire piano.
And if the distant pair exists specifically to capture the room, why would I necessarily want to time-align it to the close microphones anyway? The delayed direct sound and early reflections are part of the information that creates perceived distance and depth. Removing that delay can partially destroy the very spatial information you’re trying to capture.
Same problem with covering the frame in fluffy material and carpeting the floor. What specific audible problem has been measured or identified that we’re fixing? If there’s a bad floor reflection, fine — deal with it. But if I’ve paid for a beautiful acoustic room, I’m certainly not going to start covering reflective surfaces just because reflections exist.
“No microphone stands” being important also needs an explanation. Good stands and shock mounts are used on excellent recordings every day. Hanging microphones can be useful for sight lines, access or isolation, but there’s no obvious acoustic principle by which a microphone becomes better because its cable comes from the ceiling.
Likewise, secure your cables so they don’t transmit mechanical vibration. Fine. But dressing every cable in fluffy sleeves so it doesn’t become a resonating “string” sounds rather like a solution looking for a problem.
For a natural solo grand recording I’d start almost exactly the other way around:
Find the position where a very good stereo pair already captures the piano as a coherent instrument in the room.
Then ask what is missing.
If I need more attack, definition or control, add close mics. If I need more room, add an ambience pair.
Six microphones might eventually be the answer. But “six microphones” shouldn’t be the premise.
The fundamental difference is that I’d try to record the piano, whereas your (100% unproven) approach seems to record a collection of piano components and then try to reconstruct the piano afterwards.
