Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum string wrap ratios

Hey this is for you string scale designers out there.

I am trying a new bass string company. My scale calls for a string wrap ratio of 4.9 in the bottom notes(A1 = L-1108mm Core-49 OD-241). Stringmaker is uncomfortable with anything over 3.6. Does that seem awful low to you?
I always thought staying under 5.0 was ok for singles, and staying under 3.0 for bi's were ok.

Thanks for your feedback

I'm no expert on this subject and can't comment on the validity of 3.6 being to low, but as you increase the ratio over 3, you significantly reduce the volume and sustain you will be getting from the string, although the harmonic purity will be good for your efforts. It is not a linear relationship so maybe the stringmaker is aware of this. With a high ratio (reduced core surface area), it becomes more difficult to properly secure the wrap also...I believe hex core strings were born out of this problem to help stave off unraveling in higher ratio applications.

Are you sure that you and your string maker are using the same method to calculate the ratio?

Are there any string makers out there who can make a bass string with this information?
1108mm speaking length
hitch to bridgepin 84mm
hitchpin to winding 99
hitch to agraffe 1191.
.049 core .241 O.D.?

Then you got the job.

You will likely want to get a measurement for the length of fore string from the agraffe to the tuning pin also to complete the information. String makers typically want to minimize the length at which they chuck the string at when winding wrap in order to keep proper tension on the core.

Mapes says not to go below .051
So now that's a 4.7 ratio. That's a heck of a lot closer than 3.6

I've never gone below .051 myself, and I tend to favor the monochords to have a thinner core and thicker wrap, because I think it sounds cleaner and clearer. I'm no expert on the ratios either, but I have heard the comment about loose windings if the ratio is too big because there is not enough purchase.

I think you are talking about J. D. Grandt as the string maker. I looked up A1 for a Steinway B I finished about a year ago that he had made the strings for. The bass was rescaled by Arno Patin. The core was 1.4mm. and the outer wrap was 4.8 mm. That's a ratio of 3.43. Here's the thing: The core wire was the Paulello Type O wire, and the % Practical Breaking Load was 42.31.

My desire would have been a smaller core at the outset, but the bass strings on this B were the best that I have ever heard on a B - rich, sonorous, clean, and clear. So the world is a little bigger than I thought it was.

What make and size piano is this for?

I don't think volume is really an issue for your desired ratio, as long as the bass is scaled evenly and to the rest of the scale. Generally, the monochords are the loudest part of the bass, and the bass is louder than the rest of the piano.

As far as I am concerned, even if Mapes would wind that .051 core, they will not get my business. The quality of their strings is pedestrian, and audibly inferior to JD Grandts.

That broadened my horizons. I think the wild card here that may be the important influencer is the use of the Type O core wire.

I would 100% agree with this. I took a tour of JD Grandts facility years ago and its top notch along with his equipment being state of the art, as is the quality of wire they use. Been in business a long time, knows his stuff, and I like the way in which he terminates and secures the windings. Occasionally he posts on here in this forum.

Thank you William,
This is for a piano I am designing. A 5'1" grand. I'll have to look into the Paulello wire, seems to be a lot of interest. I am changing the core to 51 most likely.

I'm also going back and study some old 5'1" scales.
Anyone out there have any small grand scales I could study?
I would need Length, Diameters, in the bass- core and outer diameter.
There must be someone out there besides myself that saves that stuff!?
Email perhaps best.

Oleg just sent me the Fenner Bass string book. Good read so far. By the way, I have always depended on "Some thoughts on the design of Bass strings" by Richard M. Brown PTG Journal August 1998. I like the way he lays out a "map" that makes it easy to understand.

I have done 4 pianos with the Paulello wires, all with JD Grandt bass strings with the Paulello cores. A Steinway B, a Bechstein C (7' 3", 56" Ivers & Pond upright, and now an 1893 Mason & Hamlin Screwstringer. My impression for each has been that the pianos could never have been scaled this well or sounded as good as they do with any other wire. Coherent and balanced, and beautifully blended.

As I have done my own scaling using this wire, I have become more aware of its strengths and potential for the least compromised scaling. It seems to me that this would be especially true for a small piano, which is a low tension scale because of the short speaking lengths. And, as you know, there are significant compromises in such scales.

The Paulello wire is foremost wire of the very highest quality available in the world. That is true for any of the 5 wire sizes. Even if you used but one type (M) it would be better sounding. But that does touch the potential of the wire.
The history of the evolution of piano wire follows the metallurgy that made higher and higher tension wires possible with the advancements in metallurgy. 200 years ago piano wire and the scales for the pianos were low tension because that was what was possible then. Throughout the 19th century tensions rose as the wire got better.

The Paulello wire mirrors those types of wire. From the lowest breaking point to the highest, the Paulello wire goes from Type 2, to 1, to 0, to M, to XM.

Short scales suffer from low tension and low breaking points in the bass and tenor. This can be addressed with wound strings, but there are limitations to what the wound string scaling can do to raise the tension and have the breaking percentage in a range of acceptable tone. What is different about the scaling with the Paulello cores in the bass is that you can substitute a wire type other than the M type (the rough equivalent of Mapes or Roslau wire) with a wire of a lower breaking point (usually type 0). This raises the breaking percentage higher and into a range where the string sounds better because the 0 type wire is at a higher breaking percentage. I think you would be surprised how much difference this can make to improve the tone, particularly in the monochords. And how well this can blend with the bichords if scaled thoughtfully.

This is no less useful in the plain wire, particularly in the tenor section. You can substantially raise the breaking percentage of the whole tenor while maintaining the same wire sizes and tensions of your scaling, just by substituting different wire types - type 1 once you have moved from whatever wound bichords you may put on the tenor bridge, and from there type 0 until a transition to type M is most beneficial. The best results will come by rescaling with breaking percentage as the foremost consideration, and changing wire types where the scale dictates. But this will not be very much different from the decisions you make in your scaling considering tension, inharmonicity, etc.

I will even be so bold as to say that, no matter how good the scaling of your piano is (and I will assume it is very good), it can still be improved by the substitution of the Paulello wire and using breaking percentage protocols. The level of improvement that I have seen in all the pianos done with this wire allows me to say that with some confidence.

WilliamTruitt,
Thank you for taking the time to explain that. I appreciated it.
I will look into the Paulello and program the 'different" breaking strain percentages and compare the difference. Strangely that sounds like fun!
Thanks again.

Very useful information William, thanks for taking the time to share it. I am restringing a Steinway L in the next few weeks and was considering my options as the budget is good for this project.

Hi William,
Would you have any sound samples of the Paulello?

Hi Chernobieff and Emmery as well:

I am sorry to say that I do not have any sound samples, or I would share them.

As for scaling with this wire, Arno Patin (who was the importer of this wire until recently) sells an Excel spreadsheet that is quite extensive, allowing you to calculate % Practical Breaking Load, blank inharmonicity, bass inharmonicity, tension, loudness, and other things. I have a list of Paulello wire sizes and types that JD Grandt carries, along with the Deagan Copper wrapping sizes. That way I can scale the bass using exactly the materials that he has on hand. This spreadsheet calculates the %PBL for each wire type and size. There are also extensive graphing functions that are part of the database. It is well worth having and gives me consistent and predictable results. You can reach Arno at arnopianos@aol.com. He is a real gentleman and you will find him great to deal with.

As for the wire, you will have to order it from Stephen Paulello in France because there presently is no importer. That is less of an inconvenience than you might think - even when I ordered the wire from Arno it was shipped from France and I usually got it in about 4 days. It is also more expensive. Depending on the wire type, 2 to 3 times what we pay for Roslau. It is well worth it. And you will need more wire sizes and types. I've been buying it as new scalings ask for an addition. I'm up to 29 sizes and types presently, and expect I'll have everything I may use in the mid 30's.

There is a lot of information about the wire still on Arno's website arnopianos.com and also on Stephen Paulello's website stephenpaulello.com.

You can contact me privately if you want me to run some things through my spreadsheet for you.

One other thing that I should make note of pertaining to the various wire types - the wires with the lower breaking percentages are not as stiff as modern wire. Those of you who restring would immediately notice that the type 1 wire handles differently, and is more flexible than modern wire, as is the type O. The type O is less flexible than the type 1 and not as stiff as the type M.

Let me also add that when the breaking percentages change with the wire type, the tension does not change, nor does the inharmonicity. Perhaps a bit of you get your cake and can eat it too. I think the inharmonicity of the wire itself is lower than Roslau or Mapes, due to the higher standards of manufacture and greater consistency.

Changing the gauge of the wire, no matter what type it is, will change the tension and inharmonicity without changing the percentage of the breaking strength. There is no relationship.

My comments were not directed to changing the wire gauge - only what happens when the wire type is changed. You will see that if you reread my comments carefully. Depending on the criteria used, one can choose to change the wire size when rescaling with Paulello wire, and that will change the tension and inharmonicity, just as it would with other makes of wire.

William, do you get concerned about higher incidents of string breakage with use and age, when you increase the breaking point percentages as you do? Are their certain models/sizes/ brands you would not consider the changes because of this?