[pianotech] Sound from strings

Andrew & Rebeca Anderson anrebe at sbcglobal.net
Tue Mar 31 03:44:25 PDT 2009


There is some prep in new instruments that should be done that may  
minimize the noisy partials.

Of-course a careful regulation should be done prior to any voicing.

Before tuning, tighten the string curve around the hitch pins and  
seat, gently on the back scale bearing.

When pulling a new instrument up to pitch, go back through and see if  
it stayed there.  Take a cloth and actually push down on the speaking  
length to make sure the tension rendered through the bridge to the  
backscale.  Then follow this with a vigorous drumming: activate the  
damper pedal and paddle your way across the compass back and forth a  
couple times.  Scares the customer but again it loosens up the bridge  
to render tension across it.  Retune as may be necessary.  Listen for  
zings from poorly shaped damper wires coming into contact with the  
excited strings.

Some new pianos will not have their strings all the way down on the  
bridge (or even on the correct bridge pins!).  Gently drift the  
strings down keeping in mind that deforming the much softer maple  
bridge will contribute to noise a lot.  Gently push the speaking  
length of the string back against the bridge pin which in some cases  
tighten the curve a little.  Level the strings up front by lifting on  
lower ones.  A string level gauge can help but you may also place some  
thin cloth across the top of the jacks which will allow you to stop  
the hammers on the strings with a gentle stroke down on the keys.   
Pluck the strings and if there are any open strings lift the ones that  
aren't until all are stopped by the hammer (this presumes that the  
hammers have already been shaped to remove any cupping).  It may be  
necessary to file the hammer to fit the strings if the agraffes are  
cock-eyed (even on S&S) or the hammer is mis-shapen, be prepared to do  
both lifting and shaping.

Another source of noise is damper whooshing.  Cut-off excess damper  
depth on the bi and tri-chords.  Use damper parallel pliers to  
compress where necessary.  If the piano is new out of the box, give a  
day or two on its feet before you concern yourself with how the  
dampers sound.  Listen for damper wire zings on test blows.

On some pianos I will lift strings on both sides of the capo and seat  
them on their front bearings to clean up duplex noise.  Some duplex  
voicing with lacquer or duplex tuning with string couplers may be  
desirable.

If there still is too much noise, voice the hammers giving special  
attention to the shoulders to provide a cushion under the firmer  
kernel at the strike point.  Shoulder voicing tends to emphasize the  
first partial and weaken the higher ones.  It is also done to increase  
the perceived volume (loudness) of a note.

You can make a lot of difference to a new piano.

When miking a piano you do not want to point mikes right at the strike  
point on the strings.  Try aiming them at the bridge if the rear  
duplex isn't too noisy, just forward if it is.  I do mike my pianos  
from underneath.  This does require the trapwork to operate silently.   
I point one mike up at the upper mid treble bridge and one at the  
lower mid bass bridge and adjust balance while someone is playing.

Good luck and have fun!
Andrew Anderson


On Mar 31, 2009, at 4:22 AM, Renee Ingeberg wrote:

> I wrote some days ago about the sound coming from the strings in a  
> grand piano, after the sustain pedal is depressed. The question came  
> from a customer in one of the studios where I tune. I have heard,  
> from a very good technician here that putting microphones under the  
> grand can be a solution but that is another subject...
> I have noticed that the amount of sound coming from any instrument  
> varies in this respect and there can be a substantial amount of  
> noise coming from new instruments.  I tuned a new grand the other  
> day and there was more sound coming from the strings, when the pedal  
> is lifted, than from an old grand, for example. So I am wondering  
> what the cause of this could be.  Any suggestions are welcome.
>
> In the latest Journal, there were some really good articles on aural  
> tuning. I especially liked the mention of creativity, being in  
> contact with the piano and 'coloring'. Over the years and tuning all  
> sorts of pianos, it's really a matter of trying to 'conceal' or  
> cover up the inconsistencies and making the best possible result.
>
> Renee
>




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