(Airy scale questions)

[Ron Overs]

Stephen and list,

Stephen wrote:

>I was wondering about something. I know of a piano
>that has a 56" A1 string length.
>
>My question is --
>
>Where would you say the bass/treble break would be and
>what note would the lowest plain trichord be on such a
>piano?
>
>I will say that the wound bichords start at note G
>(11) (there are 10 wound monochords).


>Oh I also forgot to say you can answer based on where
>the break is on current pianos with similar string
>length....

While the piano is possibly a grand of around 6'6" (if it is indeed a 
grand), I can't see the utility of your question. As Del said, the 
break could be anywhere. Furthermore, consideration of the speaking 
length alone is not enough. The back scale length is just as 
important as speaking length when designing a scale. Very often, 
designers choose speaking lengths which are inappropriate for the 
length of the piano. There's no benefit in having a 140 cm A1 
speaking length in a 185 cm piano if the bridge is practically 
sitting on the inner rim with a lousy 100 mm back scale, only to 
sound more like a xylophone than a piano (no, the suspended bridge 
will not help either, it will hinder the tone further). A well known 
contemporary manufacturer recently revised their 185 cm grand (out in 
length from 183) to these specs only to make the bass response worse 
than that of the previous design. And while the sales folk will 
'rabbit on' about the longer bass string, its performance will only 
prove to be like the sales person's knowledge, sadly lacking.

You are obviously interested in learning more about piano scales and 
scale design. While it is encouraging to see that you are interested, 
as a preference to wasting bandwidth on the pianotech list with 
questionable questions, I would recommend that you set up a 
spreadsheet with which to enter scale measurements from a range of 
instruments (one sheet for each piano). You will learn far more by 
collecting a range of scales and reflecting on the trends of 
inharmonicity, impedance and percentage of breaking strain, and their 
influence on tunability and stability. Since 1985, when I started 
analyzing scale designs, I have collected nearly sixty different 
scales from pianos ranging from Yamaha's U1 to the Fazioli 308 (I'm 
not really interested in scales from 'pianos' smaller than 121 cm, 
since they're not really pianos). Yes, for most scales I recorded 
every speaking length and the diameter of core and cover, including 
also the number of unison strings per note (which is required for 
calculating impedance).

Don't assume that the better designed scales will be found in the 
top-end pianos. Some of the so called high end pianos have some of 
the poorest scale designs. The sooner we (the industry) cease to make 
assumptions about certain contemporary designs, and their merits or 
lack of, the better.

If you haven't the resources to set up a scale analysis spreadsheet 
and if you use Microsoft Excel on either Mac or IMB type computers, 
send me a request by email and I will send you a couple of sample 
spreadsheets as an attachment to get you started (don't forget to let 
me know which type of computer system you use - I will need to know 
to choose the appropriate type of data compression).

As it happens, today (Sunday Sydney time) I am designing a new scale 
for our Overs 225 grand piano, which has ambitions to grow into an 
all-Australian-made 230 cm (7'6") grand piano.

Regards,

Ron O

-- 
Overs Pianos
Sydney Australia
________________________

Web site: http://www.overspianos.com.au
Email:     mailto:ron@overspianos.com.au
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