Thunky Steinway Monochords

[David Love]

The customer has no real complaints about the tone until it gets down to the
monochords.  Will dropping the core wire diameter on the mono's necessarily
cause a bump at the bichord transition?  Unfortunately, though this piano is
fairly new, this kind of change probably can't be considered a warranty item
so the customer may be out of pocket for it, though I haven't checked all
warranty sources yet.  

David Love
davidlovepianos at comcast.net 

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Overs Pianos
Sent: Thursday, June 01, 2006 3:21 PM
To: Pianotech List
Subject: Re: Thunky Steinway Monochords

>What is the likelihood that the thunky sound of the low monochords on a
>Steinway (B) will be improved significantly by simply rescaling those 8
>notes to thinner core wire and double wraps.  And if I do that, what
problem
>might I create with the blending between the bichords and the monochords?
I
>have a customer who is complaining about the tone at that end (fairly new
>piano).  I have not yet seen the piano so I haven't checked the bearing at
>that end which, I suppose, might also be a contributing factor. 
>
>David Love
>davidlovepianos at comcast.net


Indeed, the downbearing would be an area to check. However, the bass 
scale can be significantly improved by revising the core/cover 
diameters. With an A1 speaking length of only 150 cm, the standard 
1.6 diameter core wire is guaranteed to ensure that the bass will be 
all bark with little in the way of fundamental. The English eye will 
top off the stiffness picture to ensure that not much is happening.

We re-scale the B's bass such that A1 has a 1.25 mm core with an 
outer wrap diameter of 6.0 mm. This will reduce the inharmonicity of 
the B's note A1 (I4) down to around 0.4 cents below the A1 
inharmonicity of a standard model C. A looped German eye will improve 
the flexibility of the low a bass a little more. But you may need to 
design an increase in stiffness from A1 through to E8 , so that the 
transition to the first bichord doesn't hit you in the ear too much.

By the way, there was talk on the list a couple of weeks ago about 
the merits or otherwise of double looping German eyes. I've done 
tests which indicate that there is a benefit to using the double loop.

While both are adequately capable of withstanding string tension 
without undoing, the single looped eye has a tendency to tighten down 
on the hitch pin as string tension is applied. This makes getting the 
eye off the hitch very difficult should you wish to twist a bass 
string further. The double eye, when made using an appropriate 
technique, will not tighten down on the hitch, and can easily be 
removed if necessary. I suspect that the increased friction of the 
second loop reduces the tension on the string knot. This, it would 
seem, is why the double loop doesn't lock down onto the hitch. I 
think it makes the double loop worth the trouble.

Ron O.


-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
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Web http://overspianos.com.au
mailto:ron at overspianos.com.au
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