Pianotech

  • 1.  Another Ronsen voicing question

    Registered Piano Technician
    Posted 12-07-2018 21:07
    Hello all,
    I am installing a set of Ronsen Weickert hammers, and I was curious about any prevoicing they may need.  According to the voicing protocol sheet by Dale and Ray, they recommend a lacquer treatment in the staple area on all Ronsen hammers.  For those of you who work with these hammers often, do you do this?  What are your usual procedures?
    I have hung one other set of Weickerts, on an old small Harrington grand, and I did minimal filing before installation, and no lacquer or needling.  They sounded very warm and round, and the customer was happy with the tone.  I'll probably touch up the voicing as they play in.
    This current set is going on a small 1931 Knabe.  Any suggestions?
    Thanks!
    Laura Wright, RPT
    Ivory Keys Piano Service

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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  • 2.  RE: Another Ronsen voicing question

    Registered Piano Technician
    Posted 12-08-2018 05:02
    Play it by ear haha. I don't routinely lacquer these hammers at all. Why would you if it doesn't need it? Judge after installation. I just put on a set of new Ronsen Bacon felt hammers on an older Steinway M and I needled it down just slightly in the midrange, did nothing in the bass and treble but did lacquer the top 3 hammers. Other times I've had to lacquer from about F5 up. It really depends on the set and the belly. Don't use lacquer unless you must and then decide where it needs it and apply only what is needed.

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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 3.  RE: Another Ronsen voicing question

    Posted 12-08-2018 10:13
    One size never fits all, because you don't know if you agree with the tonal assumptions the suggestions are based on. I don't do this and I use Bacons almost exclusively. I even stopped lacquering the top of the molding from the side on Bacons, which are less dense than the Weikerts. 

    Also keep in mind, your little Knabe is in a venue, ie a living room, and probably a small living room, where a kinder and gentler (GW's phrase) sound is what probably 98% of the world would love to hear. Its not a concert hall. And...the sound will be mostly for private personal enjoyment of the pianist. So the sound produced for the person sitting at the keyboard is most likely the listening position to be prioritized, rather than prioritizing an audience physically removed from the keyboard. Those are two different sound destinations and two different sound pressure requirements. The point of a small Knabe is not excessive power. Driving them to an extent that tries to mimic large piano power makes them sound ridiculous. It has the potential to rob the owner of the sweetness that most home pianists who own these petite pianos value.  


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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 4.  RE: Another Ronsen voicing question

    Posted 12-08-2018 11:10
    Brilliantly said! Thanks, Jim.

    "Also keep in mind, your little Knabe is in a venue, ie a living room, and probably a small living room, where a kinder and gentler (GW's phrase) sound is what probably 98% of the world would love to hear. Its not a concert hall. And...the sound will be mostly for private personal enjoyment of the pianist. So the sound produced for the person sitting at the keyboard is most likely the listening position to be prioritized, rather than prioritizing an audience physically removed from the keyboard. Those are two different sound destinations and two different sound pressure requirements. The point of a small Knabe is not excessive power. Driving them to an extent that tries to mimic large piano power makes them sound ridiculous. It has the potential to rob the owner of the sweetness that most home pianists who own these petite pianos value."


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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 5.  RE: Another Ronsen voicing question

    Registered Piano Technician
    Posted 12-08-2018 11:21
    Actually, this piano is in a very large "living room", the common room in a very large and exquisite Colorado guest house.  However, it will probably only be played by guests for their own enjoyment, so I agree that the sweet sound is what I'm after.
    Thank you for your responses!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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  • 6.  RE: Another Ronsen voicing question

    Registered Piano Technician
    Posted 12-08-2018 11:39
    Laura,

    This subject will likely garner many tone building techniques incorporated by as many technicians.

    Here's Roger's take on this subject.

    I believe there is too much emphasis given to the formulation of tonal color, i.e. hardener placed here and there with a dose of needling on the shoulder or crown to accomplish the perfect tone we carry in our head.

    I believe, for the most part, the tonal color is built into good quality hammer and emphasis is best placed in building the attack profile. We often forget the piano is a percussion instrument, and as such we need to concentrate on the percussive aspect of the piano.

    The percussive profile I carry around in my head is that closely related to the marimba. A round and strong attack with a well-defined bottom end and pitch clarity at the top end.

    To accomplish this ideal percussive character I visualize a small localized hard crown and a well-supported bottom end, leaving the untouched midsection of the hammer felt to act as the "spring."

    I harden the shoulders with acetone and key top material (sometimes lacquer) and the crown with lacquer. With the shoulder providing a good solid support, the crown voicing becomes easier and more self-evident to formulate as you apply the lacquer. I apply lacquer that is thick as molasses to prevent soaking too far into the depth of the felt. Once the lacquer has hardened (about 6-8 hours) it becomes easier to adjust the depth of lacquer penetration by adding a drop or more of lacquer thinner to the crown. This technique does take practice, especially ones tendency to over penetrate the felt. I take it in small stages until I get the "feel" of the lacquers' interaction with the felt.

    In the end, my perfect "voiced" hammer will emulate the attack and decay of my conceptual marimba percussive profile.

    Don't over simplify my basic concepts, as there are additional techniques one must have in their arsenal to reach these goals.

    Roger






  • 7.  RE: Another Ronsen voicing question

    Registered Piano Technician
    Posted 12-08-2018 17:56
    We voice for two main reasons: 

    1.  Relationship between attack and sustain phase (I think of as impedance matching)
    2.  EQing.  We can to some degree control timbre or balance of partials, though we are limited to some degree by the characteristics of  the hammer and the belly.  

    The impedance matching phase will be a function of the hammer-belly match, personal taste, where in the scale we're talking about, hammer characteristics including mass and stiffness.  Mass we can change to some degree by either filing, tapering, adding lead, binder clips, etc., and can have a real impact on our the amount of energy delivered.  This is an important consideration in different parts of the scale because stiffness cannot substitute for mass.  We can't get the same bass response by adding stiffness to a hammer as by adding mass, for example.  And we can't add clarity to a treble section by adding stiffness when the hammer is basically too massive.  Different parts of the scale will respond differently to changes in mass and stiffness.

    Stiffness we control by either adding a stiffening agent (like lacquer) or needling.  The goal is to control the amount of energy delivered to the soundboard via the string and that requirement will depend a lot on the impedance characteristics of the belly.

    Timbre or the relative strength (or even appearance) of the partials is more complicated because it combines with impedance matching.  For example, if we are delivering too much energy because the hammer is too heavy then needling it to get the hammer to absorb more energy will help with impedance but the more massive (and now softer) hammer will necessarily damp more high partial energy especially in the treble section.  Needling the felt also compromises the hammers ability to rebound off the string as quickly so it will tend to damp more energy where the period of the fundamental is more closely aligned with the hammer contact time--again, a problem in the low treble section often.  

    Lacquer can also change the dynamics of the hammer rebound characteristics so increasing the stiffness of the hammer doesn't necessarily translate into more "spring like" behavior.  We can stiffen the hammer and increase the high partial energy but it won't be the same partial distributions as using a hammer that is as stiff to begin with but is more springlike in the decompression phase (know as the coefficient or restitution).  The higher the COR the faster that hammer rebounds off the string and the less damping it does.  Lacquer and needling both compromise the COR and thus result in more high partial damping.  A soft very resilient and spring like hammer naturally will tend to produce more high partial energy that a hammer that is made soft by needling.  Over time that problem gets worse (as well as the hammer becoming less stable).

    Thus, there will always be differences in timbre (you can see this by comparing spectrum analyses) between two hammers who achieve roughly the same impedance matching characteristics by means of voicing rather than the natural state of the hammer unadulterated.  Whether one prefers one or the other is another question but it should be clear that you cannot achieve parity from two different starting points.  There will always be differences in the dynamic behavior of hammers depending on how you go about achieving the impedance characteristics that you are after.  Those differences will be evident  when you compare two hammers with two different treatments at various dynamic levels.  Therefore, you are always better off, IMO, starting with the hammer that is as close to what you are after as possible so that intrusions into the structure of the hammer are kept to a minimum and the integrity of the hammer is preserved as much as possible.    





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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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