Originally posted by Opus31no2:
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! [/b]
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.