Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum "Fully Tempered Duplex Scale" Tech article coming March

But to be fair, that piano did have some duplex sounds/noise. Which of those words one chose to use would depend on how one wanted to view those sounds aesthetically. Larry was able to massage the duplex conditions to quiet the sound/noise to suite American aesthetic tastes.

In a piano with that many new systems, it would be hard to pinpoint what sound/noise was caused by what system.

I look forward to playing that piano at Larry's Piano World party tomorrow. Any chance you'll be there Roy?

Jim Ialeggio

ROY123,
You described the flexing of the duplex string segment across the pivot termination as wasting energy carried by the struck string segment. The opposite occurs-the flexing of the duplex segment is not wasted energy, it returns energy to the struck string segment as it returns from its displacement. And as long as the duplex T-mode is distant enough from the T-modes of the struck string-almost none of the duplex movement is coupled to the air. Flexing alone of the stiff piano string at the forward termination wastes more energy heating up the wire at that point than a pivot.

The pivot termination greatly helps with making the fundamental stronger. And in the treble the fundamental is KING.

One of the most important parts of a FTDS scale is that the pivot termination conditions are blended and proportioned across the compass in a way never before accomplished. This helps with producing a more even and full tone quality.

For those that are interested, the FTDS patent application can be viewed online at www.freepatentsonline.com/y2013/html

That link does not get to the patent, but a search brings it up.

I have given it a quick perusal, but I am not clear what exactly is being patented, nor what the advantages are supposed to be.

I would still appreciate a recording. I am reminded of the person who visits a shrine at which hundreds of crutches have been left by people who believed that they were cured by prayer at the site. The person also sees a piece of paper that says, "One artificial limb would be sufficient!"

Sorry I didn't make it a link, I don't know how. PW assumed I linked it by editing in the underline.

The advantages have been explained in my previous posts. I have solved the duplex noise issue some notes of the prior art always exhibit.

This is the link to the actual patent.



I am not clear on what the "duplex noise issue" is. As I said, a recording that shows it would be nice. Not knowing what it is, I could not say whether you have solved it or not.

Most problems that seem to be related to duplex scales (or more accurately, the portions of the strings beyond the speaking length) I have found to be due to tuning issues. Some of them are voicing. These are problems pointed out when someone puts something in to mute off that portion of the string. When I pull the mute out, there is usually no difference, or it is something I can improve by tuning or voicing.

BDB,
On every trip to the soon to be closed basement at Steinway Hall in NY-I have seen C&A pianos with felt stuffed into the duplex behind the capo bar. They must be hearing something that they don't want ringing. You said you don't usually notice a problem when you remove the felts and if you do-tuning and voicing fixes it. Troublesome duplex noises are commonly known in the industry. That is the problem I solved.

Problem duplex noises can be reduced by tuning/phasing unison strings/needle voicing/hammer shaping-but these things just mask the problem.

(I would also like to thank you for granting my patent-since your post included "This is the link to the actual patent"-I know you are influential BDB-but I never knew your duties included Patent Examiner") CHEERS

I welcome you to judge for yourself if you can find your way to my shop in Mukilteo, WA. And while you are at it bring your recording equipment and we can make a recording and post it if you like.

I wanted to bring this topic back because today I tuned two 1990's Steinway B's that I regularly maintain and I think the comparison between them may illuminate this topic some more.

Both B's have been completely tone regulated by me some years ago. One B has a capo bar so hard it cannot be reshaped. The other B's capo was reshaped and is soft. (By reshaped I mean brought to a definite V at the string contact point-no radius other than that which the string works into it.)

The treble of the hardened B is ringing like metal. Echoey, chiming, sizzling sounds arise with every note in the capo section. Also, some duplexes are very close to unison with T-modes of the speaking lengths-those notes are the most disagreeable. In contrast, the agraffe section sounds warm and rich.

The other B has a relatively even warmth across the compass. It sounds thrilling when pushed and can whisper with the best of them.

The only significant difference between them is the hard capo. The extraneous, ugly treble sounds from the hard capo are not all just extra strong T-modes. You can hear the pulsing of very fast beats. These beats do not go away when the T-modes of the unison is tuned.

My contention that L-modes can produce audible beats is the only explanation that can be found.

Ed, congrats on your deplex scale innovation. I only tune and service pianos, but I appreciate someone who makes the instrument BETTER!

Thank you Gary for the kind words. If you ever are in the Seattle area please try to find the time to visit my shop. I would very much enjoy showing you my pianos.

It is difficult to innovate in such a mature industry such as the piano. But the mystery of what contributes to making an instrument with a great capacity for musical expression is one that intrigues me. When I was young and just starting piano work, I kept looking for some old guy who knew all the elements. I felt sure there had to be someone who understood the physics and engineering. When events evolved that staying in university was no longer necessary to avoid going to Vietnam-I dropped out thinking that "I'll get this piano thing figured out and then I will go back to finish my chemistry degree."

I never found that "old guy" until recently-I looked in the mirror and I was OLD! But I still don't have all the questions answered-and maybe don't even know all the best questions to ask! And I still don't have a degree.

Ed...

Please...

Get this invention recorded properly. It will be worth it. We're all so excited to hear it. Pretty please?

Yesterday a colleague and I were able to check out Ed's freshly remanufactured M&H BB (1970s vintage) which features his FTDS design. This instrument was purchased from Prossers in June of this year for a neighborhood high school performance venue. Prior to that it had received no reconditioning excepting hammer reshaping and periodic regulation. Given Ed's extensive handiwork,(new block, rescaled lower tenor and bass section(Mapes custom made strings with stainless steel wound tri-chords at the tenor/bass break), WNG shanks,Ronsen hammers, key rebalancing, reconfigured bridge thicknesses and other modifications best explained by Ed, I can't say to what extent the FTDS alone is responsible for its substantially improved clarity, power, and sustain in the last two octaves consistent with Ed's claims. I can say that in its unrestored state, from C5 up the treble displayed the problems Ed has enumerated as does the 1971 Mason A we're about to rebuild which has resisted conventional hammer mating/voicing and string leveling remedies. At the very least his FTDS which includes meticulous reshaping of the V-bar, height/alignment of agraffes and counterbearing angle adjustments has effectively eliminated any sizzles, snare drum/buzzes noises. In combination with optimizing strike point and his choice of Ronsen hammers, the tails of which he aggressively tapers to around 5 or 6 mm in the high treble (possible with WNG shanks) to lower mass, I suspect the FTDS contributes in large part to the greatly improved sustain, power, singing quality and color in the upper register. Over a range of dynamic levels the piano's tone was even, full-bodied and orchestral sounding without ever becoming strident even at fff. All in all a marvelous piano now. I will be visiting the music director at the H.S and may have more to report in a later post.

Ed, I hope this is the thread you asked us to revive.

I would like to ask about longitudinal modes and the reduction in energy loss mentioned in the quote below.

Two points: first, do you find that an increase in sustain tends to go hand in hand with a reduction in the sound level of longitudinal modes? Second, have you thought about the energy transfer mechanism at the capo bar, specifically at the surface of the string in contact with the bar where it has "machined" its groove?

Withindale,
Thanks for the questions. I think most of the increased sustain is due to more effective pivot termination-but I haven't tried to separate that out from changes in L-mode energy-and don't really see how I could.

As regards the capo bar-I have done work with temporary modifications to increase horizontal stiffness. I have also experimented with temporary attachment of damping material to it. Many capos are way too flexible out in the middle of the section and this increases hammer knock noise and "wobbles" the vibrating string. This increases the duplex hiss. I am working on a piano now that has a much stiffer V-bar horizontally so when completed that will provide more evidence.

Ed
I was trying to test the hypothesis that a more effective pivot termination not only increases sustain but also reduces the amount of vibrational energy dissipated as L-mode sound at each reflection. That's based on the idea that a less effective termination will restrict the flow of longitudinal waves along the string, generating L-mode sound and noise.

Thanks for the tip about hammer knock noise and "wobbles" in the middle of a capo section, something to check.

L-mode can pass right over the V-bar. And since all three unison strings are ever so slightly unequal in speaking length and the same with the duplex rests-6 different fundamental L-modes can be carried by a unison. These frequency differences can create audible beats. Even though the frequency of the L-modes are above audible range.

The T-modes in the duplex unison can also beat with each other and when the L-mode beats meet the T-mode beats there is a whole lotta sizzling going on. Some of this noise is quite short lived as the L-modes are damped by the bridge. But when you add in capo flexing and bridge rocking another set of L-mode excitation sources start up.

My one NY-minute trip through that basement didn't reveal this but I don't doubt it. Have both seen (and used) these masking techniques in numerous pianos - C&A and others - over the years. The occasional confused look I'd get when explaining to client that "the little piece of felt you see is not a mistake - please do not remove" is still a fresh memory. Thanks for solving the problem.

Is it possible to post the new link to the PTG article? The old one is broken.

Ed,
I wish you much success with your invention, but honestly, I was deeply saddened by your comment above.
I wish to take this precious moment to thank all of the Veterans who put their lives on the line for us to have the freedom to work on and enjoy the piano.