Kawai K25 buzzes when sustain pedal is pressed

[tklee]

Hi,

I don't play piano so this question might be really dumb.

This afternoon we received our Kawai K25 piano. I notice something that I didn't notice at the store: when the sustain pedal is depressed, and you hit a higher note, you hear a buzzing that reverbs as long as the pedal is pressed. The middle notes are not as obvious, and the lower notes are not perceptible, but I suspect it's there also. If I hit a note, *then* press on the sustain pedal, I don't hear the buzz.

My analysis says this buzz cannot be avoided since all the dampers are lifted when the sustain pedal is depressed. When you hit a note, all other strings will vibrate somewhat, and that might be where the buzz is from.

Am I right? Or is the instrument insufficiently damped to isolate strings for different notes to avoid such resonance?

Since I don't play the piano, I can't tell if one should ever depress the sustain pedal first before hitting a note or not.

Thanks and best regards,
Teng-Kiat

[Dazzer]

does it still buzz with the pedal down? usually, if i get what you mean, buzzing occurs when there's a loose metallic part somewhere in the piano that resonates to a particular frequency (like a snare drum... annoying) so it would also resonate pedal up or down.

if not, then it may be part of the dampening mechnanism that is resonating?

[quantum]

Also check items near or ontop of the piano.  Eg: the piano lamp.  It is also possible for other items in the room to sympathetically vibrate when a note on the piano is struck.  If you do have such an item buzzing, repositioning it will usually solve the problem. 

[jeremyjchilds]

It is either part of your piano damper mechanism, or it is a single (or group) of notes that has a stringing problem.


Play each note carefully, one at a time. Check to see if there is an individual note that makes that noise.

Five guesses:
1) You may have a bass string with a loose coil
2) you may have poorly adjusted downbearing in your mid to treble sections.
3) your pressure bar may have grooves worn in and may not be seating the string properly
4)Your strings may not be levelled.
5) you May have a section of the bridge that is broken or detatched.

For all of these, you are going to need a tecnician.

Check with your store, they will likely take a look at it...if they are big on customer service...

[tklee]

Thanks all.

Dazzer: when you say "with the pedal down", you mean not pressed or pressed?
             or do you mean "with the damper down"?
             When the pedal is not pressed (damper down), everything is fine. When
             the sustain pedal is pressed *after* a note is hit, everything is also OK.
             There was one note (a C above middle C), that caused my sheet music
             flipper stand to vibrate. I could stop that vibration easily.

Quantum: At this point, there is nothing on the piano. The sound is clearly coming
                 from inside the piano. There could be something in there. But I doubt it,
                 since there is no buzz when the sustain is not pressed.

Jeremy: Wow, I definitely need a tech then. Are you saying there should be absolutely
             no buzz (I hope I am using the right description here, Dazzer's description
             of a snare drum is quite close to what I hear also) when the sustain pedal
             is pressed before hitting a high note?

I'll go to another store to hit a few pianos later during lunch.

Thanks.

[jeremyjchilds]

Did you play each note carefully and slowly?

[tklee]

Thanks all. Besides going to a store again, I also got an RPT to check it out. What I heard was the sympathetic vibration and it's normal.

Best regards,
Teng-Kiat