[CAUT] Snarly bass, was RE: Rubenstien Piano

[John Delacour]

At 1:42 pm -0600 4/3/07, Ron Nossaman wrote:

>>Single wrap strings. Double wrap strings sound better, My mentor 
>>uses double wraps.
>>  Keith Roberts
>
>I much prefer double wrap monochords too, but what string winder can 
>do double wraps for 9' pianos? They don't want to go below 0.017 for 
>an inner wrap, when a D sized string wants 0.015">0.011", or 
>thereabouts. Going from the original 0.063" re-bar to an 0.051" core 
>wire helps a bunch though.

Speaking as long-established string-maker and restorer, and without 
commenting on the tonal pros and cons of double-covered and 
single-covered strings, I am interested to hear that "they" "don't 
want to go below 0.017", which would be our 0.45mm.  There is no 
practical reason why a thinner under-cover cannot be used, though 
very few pianos have been designed to require it.  Notable exceptions 
are BlŸthner grands and older Brinsmead vertical-strung pianos that 
have several pairs of double-covered bichords.

I will look at the D scale lengths tomorrow and see what would be 
required.  What core and tension would you want on note 8, presuming 
you are not increasing the number of singles to 10 or 11?

I must say that working with a soft copper under-cover less than 
0.45mm is not without risks when you work with certain ratios since 
the under-cover can get over-crushed and lead to a faulty product, 
which no string-maker is happy about given current prices of copper. 
A soft iron under-cover is at far less risk of crushing, and many 
German makers used to use iron under-covers.

It's also worth noting that you will get a difference in harmonic 
spectrum according to the ratio of top-cover to under-cover -- the 
lower the acceptable ratio chosen (some ratios are not acceptable) 
the more flexible the string will be.  End-loading of the string will 
also favour the fundamental etc. etc.

You are, of course, welcome to consult with me free of charge and 
even to try a string or two!

JD