| I've noticed this phenomenon on many pianos. I think it's due mostly to the acoustic properties of the instrument. Everything below middle C or so has the full power of the piano's soundboard behind it. Unless the piano is voiced brightly that low-middle range can come across as unbalanced.
I'd also say that there is a certain amount of perception involved. What may sound normal and even "warm" in real life can sound different than we expect when heard in isolation on a recording.
Looking at some of Neumann’s frequency response charts, I notice that the directionality in their omni mics starts happening around 2kHz and doesn't get extreme until between 8 and 16kHz. The piano's highest C comes in at just over 4kHz, so any pitches affected by the change in directionality will mostly be overtones. It's hard for me to believe that missing out on a lot of reflected, soft overtones could affect the sound that much.
Anyway, this is all just speculation off the top of my head. I could be totally wrong! |