What can cause a metallic woosh (or spring) sound on high notes?

[Kobi]

Hello,

I recently bought a new PX-S1000, and noticed a distinctive metallic whoosh sound when playing high notes (it is especially noticeable at higher than G6).
This sound is probably intentional because when I set the tone to an electric piano I get a clean sound, but all types of grand pianos have this whoosh sound. It is also there when using headphones.
I tried canceling it (turned off resonance which is also related to high keys, key up and down sounds, even pedal sound), but that effect is still there.

To describe it better, it's like a little mechanical "bump" or spring when the high notes are played.

Anyone knows what that sound is, and how to turn it off?

Thanks!

[Brad Saucier]

It is normal and the sound of a real piano.  The upper notes on a real piano do not have dampers that stop the strings from ringing out.  Since a piano is a percussion instrument, you're hearing the felt covered hammers strike the metal strings.  It creates a percussive metallic sound.  

[Kobi]

Wow, thanks! Didn't know that... It's good that it's suppose to make this sound (that's what I guessed too). Still, do you know if is there a way of turning it off? For example, I thought the pedal effect was distracting coming from headphones so I disabled it, but I couldn't find anything related to this.

[Brad Saucier]

It can't be turned off.  Whenever you play a key, you're hearing an audio recording of a real piano played back at CD quality.  The sound is in that recording.