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One and all. I'm looking at a 7 ft grand, and this particular brand sounds great in the base, but has a tubby, thuddy, muffled sound at the tenor break on f#,g,g#,a,a#,b, then it clears up again, and sounds really good. These notes are not copper wound, but have 3 strings per note. I've had the first instrument ("new") replaced, and the replacement (directly from the factory) sounds the same in that spot. I've been told by one technician, that it's hard to keep the sound even in that spot on the larger grands. Is this true? Does that mean ANY brand would have the same problem?

Thanks for any insight!

You don't say what brand--just out of curiosity, what is it?

No, this isn't the case with every grand. Some stringing breaks are quite undetectable in a well-scaled piano. Different makers approach the switch from the overstrung bass wiring to the understrung tenor and treble differently. Some use wound bichords, then wound trichords, then unwound trichords, while others proceed directly to unwound trichords. Other factors come into play as well, but I've often heard techs say that it can be quite tricky to smooth out the break on those that switch directly to unwound trichords.

Thanks Norman...

You said it can be quite tricky to smooth out that tenor break. This implies it's an inherent aspect of the instrument's scaling, and not bad hammers, or strings, etc. So what does the tech have to do to bring the sound up to par with the rest of the neighboring "good" strings?

The hammers are Renner blues, and aren't supposed to be doped because chemical hardeners destroy the felt. Can the hammers be needled to make the sound brighter, and will that have to be done continuosly, and further, will those particularly hammers eventually break down and have to be replaced?

Thanks again for your advice!

I would have hoped a tech would have weighed in here before now. I am not a tech, just someone who enjoys reading the technical discussions of the PTG group in their own forum, where I've seen considerable discussion about this issue. Perhaps our discussion bumping this up will get someone to answer your questions from a more experienced perspective.

My own guess, and it is just that, is that the transition from the wound bass to the unwound trichords is most noticeble due to the relative brightness of the trichords compared to the wound bass strings. I would think the first step to minimize this uneven transition is to regulate the piano well, adjusting the attack of the hammers with appropriate capstan height and letoff, to get as close as possible to a similarity of tone by that manner first. Then I would anticipate that a tech would probably voice the hammers in the tenor region by needling them to alter the attack of the hammer on the strings in a manner that allows perhaps more of the "partials" to emanate from the strings, instead of the "fundamental" pitch dominating so prominently. This would give a smoother transition across the break. The wound strings by their nature likely produce a bit more seemingly textured tone due to the production of partials, along with the fundamental pitch. The unwound tenor and the apparent abrupt break are probably due mostly to a much higher proportion of fundamental pitch to partials in those, so bringing out some of the partials in that range, in a rather graduated manner through an octave or two, would smooth that transition.

You did not say what kind of piano this is, and I'm a bit unclear about the sequence of events you described. It sounds like the current piano is a replacement for a previously delivered piano. I also infer that the reason for the exchange may have been an effort to correct disatisfaction with a similar problem with the original. That's why I'm interested in the make. Particularly as any techs reading here will have a much better understanding of the issue based on their collective experience if you can tell us the make and model. Some models are predisposed to such issues and often as not, there's a fairly typical approach to achieving satisfactory results.

With a new piano under warranty, I would anticipate the manufacturer and your dealer to prescribe the course of action. I would expect that to begin with one or more rounds of regulation and voicing. Was that not suggested or tried with the first piano before the unusual step of replacement?

I'm also curious if this unsatisfactory break from bass to tenor occurred after a fair bit of playing. Renner blues are hard to begin with, but all hammers harden up with compaction that occurs with regular play. This may well lead to a brightening in the most heavily played middle octaves, which may make the break more readily apparent than it may have been at the outset. It may be in such a case that fairly regular hammer voicing might be required to keep the piano sounding more uniform.

In some cases, it may ultimately be necessary to "rescale" a piano's wiring to effectively minimize such an abrupt break, but that's generally the approach for a piano whose design scale is inherently problematic due to initial design. That would involve restringing a portion of the scale with a gauge of wire different than the production piano arrived with. I would not expect any manufacturer or dealer to consider that except as a last resort.

I would say it's a matter of scaling. Those are really stiff, thick and long treble wires north of the break, perhaps too stiff, thick and long. That region may be better served by rescaling with some additional wound strings. However, I'm not a scale designer, perhaps that is a foolish idea for some reason.

Some of the best sounding pianos I've heard progressed from plain treble tricords to wound tricords above the break to wound bicords. That's how the old Mason & Hamlin AA was, and I have always said that's their best sounding piano.

Regards,

Rick Clark

Much thanks Norman, Rick.

Unfortunately...or fortunately (depends how you look at it), I'm not at liberty to mention the make or model because of the ongoing warranty efforts in effect right now, and I'd rather keep it to myself because they're trying very hard to satisfy me, and I respect that kind of after sale service. Ultimately I'm sure it will be tolerable, and I can't throw out the baby with the bath water anyway...the instrument is magnificent, and I love its sound and touch, and believe in things working out.

Again my thanks.

You can type the make and model backwards so it can't be indexed by a search engine.

Besides, you are asking for advice, not indicting anyone.

In reading your first post I was thinking of 2 simple possibilities: String leveling and seating to the bridge. Coupled with that, of course, would be the hammer surface. If the hammer is striking at an angle, and not hitting all the strings with comparable force, the effects may be similar to what you wrote about.

Good luck on the piano! I hope they find the issue.

That's been my experience as well.

Speaking of wound strings above the break, I had always thought I didn't like them, or if I thought they were ok, I didn't like them above A2 or so. That was until I played an 1898 9'2" Knabe with wound trichords above the break from F2 to C#3. That was an awesome piano.

The bass/tenor break area is extremely difficult to make even in any piano. There are several things affecting the transition. First, remember that the bridge is like a transducer that converts the vibrating string energy into the soundboard for amplification. The bass and treble bridges are attached to the soundboard at different locations and are often of different construction. Also, in most piano designs, the bass and treble bridges are not connected.

For example: A#/26 and B/27 are often found at the break. Although the keys on the keyboard are directly adjacent, the spot on the soundboard where their string energy is focused can be over a foot and a half apart! Number 26 is attached on the right end of the bass bridge while #27 is on the left end of the treble bridge. It is really no small accomplishment to make those two tone qualities match. Designers will use wound or unwound strings on the tenor side for the sole reason of making a smooth transition, but as you can see, string scaling is only one part of the equation. About all most technicians can do once the piano is in your home, is hammer voicing and basic tone regulation. Most technicians don’t have the experience to improve a piano with rescaling. Besides, the designer has probably already tried everything we can think of.

Renner Blues were created to duplicate a traditional hammer design that was lost many years ago. Proper needling should bring out the best in them, however they were developed as a generic replacement product. I do not believe that they are specifically customized to enhance weak areas of any particular scale. Of course Renner makes them according to the piano manufacturers specifications but any custom voicing is up to the piano company. With that in mind, chemical hardening may not be out of the question. I would work directly with the piano companies service department until you reach a result you can live with.

Phil B. Glenn, RPT
National Service Manager
Young Chang Acoustic Pianos
(800) 874-2880 x110

To Opus31no2, it might be worth the manfacture of the piano to send you to their factory to try out all their stock so as to find the piano of your dream/choice.

It is nice that the list now has the technical representation from Young Chang, Kawai and Samick.

NB. to Phil, I thought the soundboard acted as a transducer

Even though we are talking about mechanical to mechanical energy, not mechanical to electrical, for our sake we can say that, anything that converts input energy into output energy can, in theory, be called a transducer. So yes, the soundboard converts the input from the bridge into something that we can hear, so in a broad sense is also a transducer. For most of us non-engineer types, I have found that the analogy of the string being the voice, the bridge being a microphone and the soundboard being the amplifier/speaker gives a clear mental image. The actual physics of the process is something I'll leave to those that can grasp it.

Phil B. Glenn, RPT
National Service Manager
Young Chang Acoustic Pianos

Again, thanks to all replies...much appreciated.

Here I come late as usual... but I got to sleep in, and you all obviously didn't!

Angelino, Phil, and Rick all bring up wonderful points.

There are so many factors that affect sound in any area of the piano. When the problem is over a break, it gets even trickier to diagnose. The obvious is that the problem is the break. But that isn't totally fair to say, as I haven't seen the piano, don't know how it's prepped, or who did the work.
This is where Angelino's points are helpful.
Before approaching the break as a scaling problem, I would make sure that
a) the hammers are shaped properly
b) the hammers are squared
c) the strings are leveled
d) the section is voiced by someone who knows what they're doing.
e) make sure bridge pins are seated
f) make sure strings are seated

As Phil said, you're trying to get the energy from the string to the soundboard through the bridge. You want to do this as efficiently as possible. A few bridge pins not seated in their holes can be cause for a lot of lost energy.
Now I'm not saying that this problem is due to loose bridge pins... I'm just saying that there are a lot of things to check before assuming that it's a scaling issue, and you can't do anything about it.

I'm a firm believer that voicing can cure many problems if the person doing it has enough experience.
To answer the original question, yes there might be problems in the scaling, and yes there may be a way to work around them.
Find someone who's a really good voicer, and make it clear that you want to bring a certain section out. Then see what they can do about it.

KlavierBauer

From your reference to the tenor break starting a F# can we assume this piano has a 21-note bass section? Most pianos being manufactured today of this size do tend to break around F-20/F#21. Breaking at F#-21/G-22 would narrow things down a bit.

In answer to your specific questions:

Yes, it is a difficult area to voice evenly on many pianos of any size.

No, not all pianos have this same problem. At least not to the degree it is musically noticeable. By that I mean it is generally possible to audibly pick out the bass/tenor break by fingering chromatically up and down the scale one note at a time but not be able to hear any discernable tone variation at all while the piano is being normally played.

This is a scaling problem. And when I say scaling I mean the whole of the many disparate elements that go into making up the tone producing mechanism of the piano — the string scale, the soundboard scale, the bridge layout, etc. The problem starts with the stringing scale but does not end there. Nearly all pianos in production today have stringing scales patterned after those that evolved during the 1860s and 1870s. These scales — as with the fortepianos that preceded them — tended to run the long tenor bridge down way down in the scale. Much further than is desirable in the modern piano, it turns out. A better place to break the typical 7’ string scale would be up around B-27/C-28, but tradition is a powerful force to overcome. If this is not done the low end of the bridge must take a hook back, deliberately shortening — called “foreshortening” — their speaking lengths from their theoretical ideal. One of two things must then be done, either the tension must drop or the wire sizes must be made excessively large. In either case the energy mix in the wire is going to deviate substantially from both the bass strings below them and the more properly scaled plain-steel tri-chord strings above them. And herein lies the basis of the problem. But it’s not the only one.

Another characteristic of most of these scales is that the offset between the lowest tenor strings and the highest bass strings is considerably too great. Some try to overcome this problem by using tri-chord wrapped strings at the start of the bass scale. It’s better than nothing, but still a poor solution.

To further compound the problem is the issue of bridge placement. The tenor bridge is typically way over in the back left-hand side of the soundboard, The start of the bass bridge is generally well up toward the middle of the board. The impedance characteristics of the soundboard system (or how readily the soundboard mechanically responds to energy input from the strings) are completely different at the two areas.

Several band-aid patches have been applied to this problem. Some manufacturers try to mask things by looping the end of the tenor bridge down and hooking it up to the low end of the bass bridge — i.e., the “ring bridge”. This will generally help the low tenor but it comes at the expense of the low bass. Others try putting wound strings up on the low end of the tenor bridge. Again, this helps but does not solve the problem. Most try to cope by simply voicing the bejeebers out of the hammers through the low tenor section. None of these solutions really work all that well by themselves but in combination can be acceptable. Some do such a masterful job of balancing a less than desirable string scale scheme against a carefully worked out ribbing scheme as to come up with a musically transparent piano in spite of any inherent limitations of the overall design.

As you’ve probably guessed by now I consider this to be a design problem and one that should be dealt with at the design level. Given a clean sheet of paper (or, nowadays, a blank computer screen) and modern scaling techniques, a piano of any type and size can be designed with a musically transparent bass/tenor break. On several occasions we demonstrated our 122 cm vertical to groups of piano tuner/technicians. Playing note by note across the break rarely did the majority guess it right.

Even within an existing design improvements can be made without resorting to entirely new plate castings. The most effective solution is to simply use a well-designed transition bridge. Short of this the string scale can (sometimes) be modified to incorporate bi-chord wrapped strings on the tenor side of the break.

None of which will help you very much in your current situation. If the store and/or factory technicians cannot voice the break to your satisfaction it probably can’t be done. You might try bringing in another technician whose voicing skills you know and trust but, in my experience, this probably won’t work either. If you have the opportunity you might ask to try out several other new pianos of the same model. Often simple (and normal) variations in rib stiffness can make quite a difference.

If you otherwise like the piano you might consider contacting a technician who can evaluate the scaling and give you some advice on whether or not altering the string scale across the break might help. An evaluation can be done without altering the piano in any way. And sometimes relatively simple wire changes can make enough difference to make an ugly transition much less bad.

All of this, of course, simply reinforces my long-standing advice to potential piano buyers: don’t buy any piano until you’ve played the specific instrument the dealer is offering to deliver to your home for at least a couple of hours. During this trial run make notes of any regulating and/or voicing problems that you find during this time. If the piano cannot be regulated and/or voiced to your satisfaction before you buy it, well, don’t buy it.

Del

Del wrote:

If you otherwise like the piano you might consider contacting a technician who can evaluate the scaling and give you some advice on whether or not altering the string scale across the break might help. An evaluation can be done without altering the piano in any way.

Great post!! I encounter this problem in many pianos I service. I am a simple country piano tech and most of the pianos I come in contact with are lower end verticals that will never be worthy of altering the string scale. But out of curiosity what are some of the basics of evaluating to determine if changing the string sizes would better a piano and what are some of the rules of thumb for changing string size.

Regards,
Ron

speaking of tenor sections, is it possible to voice an upright, or a < 6 ft grand, to have a tenor tone similar to this audio clip ? (this is a good quality 44KHz 320kbit mp3 stereo recording off an LP, btw... the notes in question are F2 and A#2.)

[/b]


Only very generally. Usually the problem is that the lower tenor bridge takes a hook to foreshorten the scale as was deemed appropriate by piano designers back in the late 19th century.

I will consider changes that will even out unison tension while not entirely trashing any semblance of a smooth inharmonicity curve.

Depending on the piano this may mean simply increasing the diameter of the steel wire used on the last few notes on the tenor bridge. Or it may mean converting a few of them to bi-chord wrapped strings. This generally involves adding a few hitch pins — sometimes tricky to do in a plate still in the piano.

Sometimes the problem is more directly related to the bridge. Specifically the fact that it ends. If the end of the bridge is abrupt the mechanical impedance felt by the strings down toward this end will be considerably lower than it is up a few notes. There is generally not much that can be done to stiffen things up but sometimes adding a bit of mass to the back of the soundboard immediately opposite the last bridge pin set can help. Start with a piece of brass about 1” or 1 ¼” in diameter and about 1” long. Go up or down from there depending on what you hear.

Del

ok... i figured that you'd probably have to add hitch pins when changing trichord plain strings to bichord wrapped strings. But, what do you do with the extra tuning pin hole that's left?

Also, although I can't recall any situation off the top of my head where you'd want to do it, is it ever possible to add an extra tuning pin, like if you wanted to change a bichord to a trichord, for example?

Also, what do you (or anyone) think of the tone of my upright piano on the medium-quality mp3 clips linked here ? (the mp3s were recorded post-restring, post-shoddy-job hammer reshape by me (only my 2nd attempt on moth-eaten hammers) which made them fairly thin but the tone isn't all that terrible IMHO but has room for improvement) also, here's a picture of the piano (not embedded in the thread to prevent it from having to load with the thread and making it too big). (note: the pic was taken a couple years ago before I restrung the entire piano, having the Arledge team scale the bass section, and using the same or similar wire sizes in the steel strings.) The bass/tenor break is at B27/C28 with plain trichords all the way to the break. Tenor bridge is fairly straight at first glance but if you look closely you see a little bit of foreshortening on the lowest several notes. Personally, for the piano itself, I like the break where it is, although I wish I could have plain-wire style tone (if it's possible to voice wrapped bichords on the bass bridge this way) to extend a few notes lower.

1) You either leave it or you plug it. If you plug it you can use an appropriately sized wood dowel. Paint it gold if you want. If the plate is out of the piano you can fill it with steel reinforced epoxy, seal it and paint over it when the plate is sprayed.

2) Anything is possible, but I can't imagine any situation in which I would change a bi-chord wrapped unison to a tri-chord wrapped unison. Indeed, I can't think of any situation in which I would willingly use a tri-chord wrapped unison.

Del