Piano World Home Page Forums Our Most Popular Forums Piano Forum Duplex-like thingies on Bösendorfer, Grotrian, Petrof, Samick, and Nordiska

In early October of 2005, when Piano*Dad announced the delivery of his new Grotrian-192, the discussion turned to the "duplex-like" scale of the Grotrian and folks offered various theories/speculations on what those "duplex-like" thingy contribute to the tone of the Grotrian. Piano*Dad and piqué posted pictures Grotrian-192' "duplex-like" sections, and Derick posted pictures of his Bösendorfer Imperial-290's "duplex-like" section. That discussion is at: http://www.pianoworld.com/ubb/ubb/ultimatebb.php?/topic/1/11877.html

I have since noticed that other pianos also employ this similar design element. Hence this post.

I reference Piano*Dad, piqué, and Derick's pictures here as visual aids:

From Piano*Dad's Grotrian-192, notice that there is a curved pressure bar between hitch pins and bridge and the string segments in between the two are not muted:


Another Grotrian-192 picture by piqué's, shows the same thing as Piano*Dad's picture:


Derick's Bösendorfer Imperial-290, also no muting felt between pressure bar and bridge:


And in Piano*Dad's thread, some speculated over what that design element may or may not have contributed to the tone of the Grotrians and Bösendorfers.

Well, recently I looked at that sections on grand pianos by Petrof, DongBei/Nordiska, and Samick and noticed the following:

Petrof models IV, III, and II -- no duplex, no pressure bar between hitch pins and bridge, the segments of the treble strings between the hitch pins and bridge are not muted (but those string segments of the tenor sectionis muted).

DongBei/Nordiska 5', 5'5", and 6'1" -- has pressure bar between hitch pins and bridge with unmuted string segments between pressure bad and bridge, just like Grotrian-192 and Bösendorfer Imperial-290 shown above EXCEPT those string segments of the tenor sectionis muted.

Samick 5'7" -- has pressure bar between hitch pins and bridge with unmuted string segments between pressure bar and bridge EXCEPT those string segments of the tenor sectionis muted.

So, at least for the treble and high-treble sections, the Bösendorfer Imperial and Grotrian-192 are very much like Nordiska 5', 5'5", 6'1" and Samick 5'7" in that they (1) use a pressure bar between hit pins and bridge, (2) leave the string segments between pressure bar and bridge unmuted.

(Please correct me if the above is factually wrong.)

Any one has got any more interesting theory on the magic and benefits of unmuted back scales with pressure bars?

The unmuted strings between the hitch pins and the top section of the bridge resonate sympathetically.

You can hear the effects with and without the extra harmonics by muting the upper register using a band of tuners felt.

The extra harmonic sounds that come from these unmuted sections are similar to adding salt to food.

You will taste something with the right amount of salt, but not know it is there - yet it tastes very satisfying. If that same thing were to have much less salt, it would become bland, and you would miss the flavor of the salt. That is what duplex (triplex, mixture, whatever) scaling sounds like to me.

On a separate note - I have noticed piano manufacturers have alternate ways of going after the "salt".

Some use the system as shown in the Bösendorfer picture.

Some (like Yamaha) have a system where individual capos are placed in the duplex section to give each area a specified pitch by uniformly/accurately setting the string length. This is supposed to give a cleaner sound. These capos correspond to each note, and fit three strings each. Since the individual capos are not tuneable, I think over time this design loses some of it's intended effect. But again, it is salt.

Some, like Fazioli, take it even further. Fazioli has a system like Yamaha's. However, each capo piece can be scooted forward or backward to assist in the rough tuning of that area.

I am sure there are more systems, but they all are going after the same thing. Salt.

axtremus, and all, you'll be interested to know i received an answer from grotrian on this matter of the duplex scale.

to the best of my understanding (remembering that there is a bit of a language barrier even among fluent speakers because of the technical terms), whether or not grotrian has a "duplex" scale depends on how you define the word duplex.

grotrian maintains that this is not a technical term and that the term "duplex scale" is a name patented and owned by steinway. therefore, they call what they do a mixture scale, as others use names like resonators, triplex, and so on for the same feature.

but, there is also a technical difference.

Grotrian wrote: "the big difference with our mixture scale is that each of the string parts between bridge and hitch pin has another length so that they are not able to be tuned to the same frequency, even if someone tries to do so. This causes not the “tone of a duplex” but the “colourful noise of the mixture” scale. And please believe us that we tried both and know well abut the difference."

so, my reading of this is that grotrian does have a duplex scale as we in this country understand it, as a generic term. they do not have a duplex scale in the sense of the design patented by steinway and called by that name. their design is different.

i like angelino jazzer's explanation of it as the "seasoning" in the tone. good metaphor!

There are NO duplex scales in the pictures shown.

None of the pianos mentioned by AX function as having duplexes. It isn't also just a "language" issue and any patents that Steinway had are long, long expired. Any company that makes a piano with a duplex scale can call it a duplex scale in much of the same way that all car tires are called "tires".

For that reason piano makers that actually use duplex scale designs call them...well, duplex scales and not triplexes, resonators or anything else.

The reason Grotrian doesn't call it a duplex scale is because it isn't.
I don't think anyone should try to convince companies like Grotrian to call something that isn't a duplex scale…a duplex scale, or to imply that they don't call it this way because of a language barrier.
These companies decided NOT to incorporate a duplex scale because of one reason or another.

Pianos that are single strung all the way to the higher treble usually don't have tunable duplex scales as space is limited.

Steinway, Yamaha C, Kawai RX and Baldwin have fixed, non-tunable duplexes. Steinway used to have instruments with movable front duplexes on their vintage grand models A, B, C ,D but eliminated these as years went by and are now using fixed duplexes.
The baby grands models O, L, M, S never had tunable duplexes.
Mason & Hamlin, Fazioli and Estonia have tunable duplexes.

If you pluck the part of the string between the bridge and the pressure bar that is supposedly the "mixture scale", in comparison to the same section on a piano with a real tunable duplex scale you'll hear a much more audible sound on the instrument with the duplex scale.
MUCH more audible.

Mason, Fazioli and Estonia all have tunable duplexes called aliquots. They use the more conventional loop stringing in the treble where there are duplexes, and then move to either single stringing for the wider sections of the piano, or to a 2+1 system (one loop and one single) that will retain the more important advantages of the single stringing.

Bluthner, that (in a way similar to Bosendorfer and Grotrian) wanted to go all the way to highest note with single stringing, solved the space problem by adding a fourth "aliquot" string that is sympathetic to the other strings (it isn't struck by the hammer) in much of the same way that the duplexes do.
The affect on the Bluthner is more pronounce though and it is easier to tune the string to react differently to the other three strings.

In the Bluthner, as well as in the Mason, Fazioli or Estonia the Affect is most noticeable when the key is struck with force. When playing pp there is less difference and excitement of the fourth string or the aliquot section then when playing FF.

Many, me included, like the duplex scale and believe it creates a fuller and more colorful treble with more projection.
Others like to criticize the system and may prefer an instrument without it.

It certainly seems though, that the critics of the duplex scale system are getting to be in the minority, as in the past few years there has been what looks like a "mad rush" of European manufacturers to redesign their pianos with duplex scales (I wonder if the success and recognition of modern pianos such as Estonia or Fazioli had anything to do with it).

C.Bechstein (their concert grand, the B-210 and the M/P 192), Seiler and Schimmel all came up in the last couple of years with newly designed instruments that incorporate duplex scaling.
Bosendorfer too, introduced a few years ago a new concert grand, the model 280 that has at least front duplexes.

I hope this somewhat clarify the issue.

The understring pressure bar provides a smooth, even bearing point so that one can control the downbearing on the bridge. It also looks nice. The effect on the sound is pretty minimal, as one can tell by comparing a piano that has this feature and one that does not. Same with pianos that have the backscale muted or not, a comparison you can try if it is unmuted. Same goes for duplex scales, aliquot strings and all that other stuff which provides so much marketing hype.

What makes a good piano is good overall design, good overall workmanship, and after that, good maintenance.

BDB,
Duplex scale IS a part of the overall design.
It's interesting to know that you can't tell any difference, but many people, once listening to a Bluthner with a blocked aliquot string can tell the difference easily once the block is removed. Further more, many can tell the difference by listening to the sound when the string is in perfectly in tune to the other strings, and when it is tuned somewhat higher.
It always saddens me when someone like you can't tell the difference and can't appreciate the work that I do on the Bluthner treble, gradually tuning the aliquot string from being perfectly even with the other strings, to being higher then the others as we get to the top.
Luckily, at least by my experience, people like you that can't tell the difference are in overwhelming minority.

Same goes regarding the affect of the tunable aliquots once muted.

Then we agree on this. (We agree on much more but I don't often pipe in just to say so.) In the other thread, regarding the Grotian and duplex in general, I said:

My old Chickering concert grand has the little individual bearing bars behind the bridge and ahead of the hitchpins, which are each independently moveable and not cast as a group as is seen on many pianos, and not a single continuous bearing bar as on still others. (I had moved one of them a long time ago to get a more pure unison.) A couple of weeks ago after my long-distance move, I went through the piano tightening all screws and seating all strings to the fore and aft bridge pins before the post-move tuning. I was surprised to find that on the trichords and bichords, the back section between the bridgepins and the hitchpins were of various pitches, but in a very precise and ordered manner. Each single string of a unison group had a distinctly different pitch in the rear duplex, with the left-most being lowest and the rightmost highest on every single set, with a very precise pitch interval. As I realized that, I only then understood the possible complexity of duplexing and the way that little bit can contribute to the strength of those upper partials of a note. I strip muted the rear duplex as an experiment. I found the sound to be acceptable, but lacking ever so slightly something I'd call "presence" for lack of a better word. Muting of the front duplex gave similar results."

And:

"If I were a betting man, I'd bet that by "mixture scale" what they mean is that the "speaking portion" and "non-speaking" portions of their strings are scaled to arrive at what they consider to be a good harmonic blend, without trying to augment the portion referred to as the speaking portion with a front and/or rear "duplex" (which by its nature seems more apt for the label "mixture"). "Unified" would probably be a better word than "mixture" for what they're doing. Anyway, my money's on that sort of meaning. I just don't see anything there that looks like duplexing as it's commonly thought of. (I'd still like to hear Del's thoughts about duplexing in general [or Dale Fox's expansion on what he said earlier]. I can understand why it might be an impractical idea given the difficulty of good execution in many ways and also why it'd be no fix for failure to get the speaking portion of a scale right in the first place, but what I'm wondering is that if it is done right and merely augments an otherwise well-executed scale, if it could be advantageous (even for the tech who might bill plenty of hours to tune the duplexes, however tedious and annoying that might be.) Dale's reference to "energy-robbing" hints in a direction I might understand and concur with if expounded upon, but can't just yet given the sketchy picture so far. In my ignorance, I'm wondering if it were executed right, if there's the possibility that the duplex might reinforce the upper partials of the speaking portion of the string, if properly tuned (kind of like the way unisons flatten or sing depending on how they're tuned)."

Bluthner's approach seems the most common-sense to me, avoiding as it does the difficulty of tuning a short string section to upper partials to achieve the same end of adding presence when you lay into a key with more force.

I'd be interested in hearing Dale Fox expand on his phrase "energy robbing" and addressing how that may differ between conventional styles of duplexing versus Bluthner's fourth string aliquot. (I'm still thinking that if duplexing is done right, it would not be robbing, but augmenting, though I can readily see where it would be robbing if done badly or not tuned carefully.)

However it's done, I prefer my duplexes properly tuned, unmuted, and ready to sing when I lay into the keys. What you call "color", I'm calling "presence". I don't doubt that the texture they add is part of why I prefered the Chickering concert grand to an S&S D, which to my ears sounds cold and colorless by comparison, however lovely a voice it is in its own right. When I lay into the keys, I want presence, or texture, not just additional volume. I think good duplexing gets that without resorting to volume alone to make the treble sing over the tenor or bass, keeping the tone from being shrill or piercing while still getting added projection.

*I* can hear the difference. But I have good ears.

BDB said, "What makes a good piano is good overall design, good overall workmanship, and after that, good maintenance."

I think that's quite true, but I think a good scale design can include duplexing but duplexing is no fix for a poor scale. And it seems to me to add to the complexity of even a good design and therefore certainly requires even better workmanship, and after that, even better maintenance. Otherwise it could only be a detriment. But given those, you might be "cooking with gas".

Ori wrote "If you pluck the part of the string between the bridge and the pressure bar that is supposedly the "mixture scale", in comparison to the same section on a piano with a real tunable duplex scale you'll hear a much more audible sound on the instrument with the duplex scale.
MUCH more audible."

I must diagree. I don't hear any difference in volume between my old Steinway M and my Grotrian in terms of volume, when I pluck these "duplex" elements.

The reason that Ori and others (myself included) like the duplex sound is because the scale designs that use it are too mellow without it. Grotrian stated in the same email to Pique that their design achieves brilliance through the use of a higher tension (thicker string) as well.

My old M had pressure plates that were moveable between the bridge and the hitch pin. Moving these was the accepted method of "tuning" them according to my (then) piano technician. Why does Ori say the S&S duplexes are not tunable?

Why do technicians refer to all speaking lengths that are not struck as duplex segments?

I can understand Grotrian's reservation about using the term, given their history in court with S&S. But I find it strange that people would only refer to the plate configuration of the Stenway as a "duplex" and then in the same paragraph refer to the Boesendorfer "front duplex". This also is a resonating string element (tuneable or not Ori?) that is not struck.

Ori - what is your exact definition of "Duplex"?

Grotriman,
I wrote:
If you pluck the part of the string between the bridge and the pressure bar that is supposedly the "mixture scale", in comparison to the same section on a piano with a real tunable duplex scale you'll hear a much more audible sound on the instrument with the duplex scale.



The part I want you to notice is the TUNABLE duplex scale. Maybe I should have said tunable twice and since I didn't, I can see how you got confused. Better yet, I should have said INDIVIDUALLY tunable duplexes.

The Steinway M never had a true tunable duplex scale.
Not in the front and not in the back. It does have a duplex scale though, and the design is a part of the iron plate in the front, and made of a somewhat moveable plate on the other...but when this plate is moved the whole section has to move and the movement range is very limited in comparison to instruments with true individually tunable duplex scale. In fact, on the Steinway, the movement range is so limited that it can hardly change affect when moved.

The part of the string that is meant to sympathetically respond to the speaking length of the string ( or the duplex segment) is much shorter then you'd find on modern instruments with tunable duplexes such as the Fazioli and the Estonia.
If you pluck this part on a piano with a tunable duplex scale the difference will be very audible.

Obviously this discussion is almost impossible to have in an Internet forum. One should have access to different pianos and be able to see and hear the results of the different designs and approaches.
I definitely know that I'm not articulate enough to convey ALL the possible combinations and differences maker take regarding this, or other technical aspects.

What I can say, is that for me, the true individually tunable duplex scale offers control.
While changing aliquots to different sizes and location in the front duplex scale, I can create an affect similar to make up...eliminate certain things that I may find objectionable or bring out certain things that I like.
The rear duplex is something that I like to think of more as clothing. The color can be changed and controlled by moving the Aliquots.

It is very clear to me that there are those that are not used to work with tunable duplexes and don't feel that they have any advantage. Some even feel that the duplex may cause unwanted harmonics and rings.
It is definitely my preference though to have tunable duplexes and I believe that some techs can make a good use of these.
Of course, the more experience one has with these systems the better they get in using their advantages. If one doesn't usually work with these, they may miss what I think as the advantage and feel quite the opposite, in much of the way that tech's that don't install Dampp- Chaser systems tend to criticize them.

The fact is though, that they have much less experience with tunable duplexes and although may be very knowledgeable techs their opinions are contradicted by the piano designers of modern times at Mason, Estonia, Fazioli and also now obviously C.Bechstein, Schimmel and Seiler.
I'd like to add that I'm not sure if the aliquots are tunable or not on these newly designed C.Bechstein, Schimmel or Seiler (can’t remember which had what when I saw the pianos), but they do incorporate now a duplex scale in their designs.

As for your last comments, I’m not sure I understand them…but in any case,
Your Steinway has a front and back duplex scale.
The front is fixed and the back, although can be moved very little in sections is not really tunable. Bosendorfer designed their last Concert Grand 280 a front duplex. I’m not sure if it is fixed or not. The single stringing at the higher octaves, as appear on the Bosie and Grotrian will usually leave no room for rear duplexes.

I understand now that when hoping to clarify things at my last post I probably made a mistake. There are too many possibilities and variations to go over them all here.

AAARRRGGHHH!!!

I appreciate all your comments and didn't even know you were speaking of the front duplex part when speaking of "tune-able".

But really there has to be a simple definition of duplex out there. Somewhere!

It's a word we are all using and it appears we are all using it to refer to some slightly different aspect of the piano.

I'm looking for a simple couple sentence paragraph that defines duplex as applied to the piano.

Then I think there will be a lot less confusion about what everybody is talking about.

Ori,

Can you post a picture of the tuneable front duplex on the Estonia that you are speaking about?


Thanks!

Patents expire, but copyrights and trade names do not (unless they go unused and undefended).

Aliquot- A small metal bar or plate that divides the back end of a string into two parts, one of which vibrates sympathetically, creating a duplex scale.
So if there is'nt a duplex bridge or aliquots, there is'nt a duplex scale.

It does indeed, Ori! Thank you very much for your detailed and thoughtful post. I think this helps explain why my two favorite pianos in my search were the M&H and Estonia...obviously, there's something about the sound created with the duplex scale/aliquots that I find enormously appealing. To my ears, the treble on the M&H rings out more clearly over the bass than was true in many much bigger grands I tried.

Can I ask a practical question? Is the tuning process substantially different with a "true" duplex like the M&H? Do you need a technician who has been specially trained?

Grotriman,
I don't know how to post pictures. Maybe one of the many Estonia owners on the site can do it. If none can, I'll try to figure out how to do it later.
It would be nice though if you can post pictures of your front section of the strings between the tuning pins and the capo bar. This way I could tell you at least if there is a difference there or not.

Phlindrome,
As far as I know, Theodore Steinway didn't invent the duplex scale and I don't think he had any copyrights to the name. I believe he only patented his way of doing it and thought of it as an improvement to existing duplex scaling.
I believe this is the reason that on older Steinways have on the plate "duplex scale patent", sometimes with the date of May 14, 1872.

Now, I'm not a lawyer and wouldn't presume to be one, but I think it's reasonable to assume that if Mason & Hamlin, Fazioli, Estonia, C.Bechstein, Schimmel, Seiler, Baldwin, Yamaha Kawai and others that use duplex scale (although in different forms) are free to call it duplex scale without any legal response from Steinway...it would be safe to assume that Grotrian could also call it this way IF they had a duplex scale design.
Since Grotrian DOESN'T have duplex scale design it makes the whole point moot.

I didn't say that there was no difference, just that there was very little difference. If you put a person in a room and played an old Steinway without the duplex, like an M or O from the early 1900's and then an M or O from a couple of years later when the duplex was added, or a couple of Baldwins before and after Acu-Just hitch pins, I don't think that person would be able to tell which was which without looking. Nobody noticed when the duplex aliquots were designed in or out. There are other factors that make differences in a pianos tone that make more of a difference. It isn't an important component of the piano's design.

My memory may be mistaken, but I believe Del called rear duplexes worthless, or something like that. I haven't seen a post from Del for a while--I hope he's still here. Those who extoll the virtues of duplex scales may be reacting more to the sound of a front duplex. Just idle speculation...

Ori: My 290 also has a front duplex, so it's not just the 280. There may also be other Bosendorfer models with front duplexes, I'm not sure.

As I had written in the original thread regarding these rear duplexes or mixtures/whatever in the treble, the tone produced when plucking this area lasts a micro-second. I do not think it adds much, if anything, to the tone of the piano.

Contrast the rear "duplex" with a true front duplex and the tone is much more audible and much more sustaining.

Derick

No, The aliquots on a tunable duplex scale are set when the piano is prepared so they won't really move and do NOT need to be adjusted with regular tunings.
I would suggest though that if a tech is going to change these aliquots or move them for any reason, he'd better know what he is doing.

The fourth tunable aliquot string on a Bluthner does need to be tuned every time the instrument is tuned. This may add 10-15 minutes to the tuning time. The system used on the Bluthner though is the purest and most efficient way to create a desirable sympathetic sound and enhance the treble color and projection in my opinion...
so the extra short time that's required to tune the fourth string is well worth it.
It is also my experience that tech's won't charge anything more to tune a Bluthner then they do for other pianos in spite of the additional 10 minutes...usually they are quite ecstatic to have an opportunity to work on one of these pianos.

It is the front portion of the duplex that is most effective.
Del and quite a few others believe the rear portion of the duplex, unless perfectly engineered, is worthless, draining the speaking portion of the strings of vibrational energy, and more often than not, creating unwanted noise.