Duplex Scale

In percentage, how much sound volume can the duplex scale provide?

Pianoaccordatore wrote:

What do you think?

Curiosity, what is a duplex scale?

I will respond in order.

Sergio, I believe it is difficult to quantify the sound volume of the duplex scale.

If you have or have access to a grand piano, you can realize the importance of the duplex scale by doing this small test: play a note and listen to it carefully. Then attach a small strip of drawing tape to the segments of the duplex string to "silence" it. Then resonate the same note as before and listen. You will notice that the second time, with the duplex scale "stopped," that note will not have the brilliance and resonance of before.

Marcello, the duplex scale is that metal plate placed between the bridge and the plate tip in the grand piano.

Thank you Piano Tuner,

we can assimilate the strings of the very high notes (which are also devoid of dampers) to a duplex scale that does not disturb at all, on the contrary...

Good work, Sergio.

I forgot: in my grand piano, the duplex scale is not adjustable but has a fixed bridge set by the manufacturer.

Pianoaccordatore wrote:

Marcello, the duplex scale is that metal plate located between the bridge and the plate tip in the grand piano bass section.

Thank you

. . . I was also waiting for the response from Pianoexpert. . .

Great Paolo, what do you think about the duplex scale tuning?

Almost all duplex scales are tunable. By moving the plate. By moving the plate or plates, the load on the soundboard is also slightly modified. The Duplex scale is generally tuned to the fifth or the octave. Manufacturer's choice. When removing and changing them, this choice should be respected. Different is the front portion called the "resonator". That is, that front part of the string beyond the nut, in the high notes, which makes the highs more sonorous. See Steinway. Sometimes, however, especially in domestic spaces, over time, a sound is produced combined with a slight "buzz" that is annoying. In that case, one proceeds to partially silence these portions of the string with small felts that can be positioned at the best point of the section. It is a very difficult and thorny subject. Every instrument should be listened to and, before moving the Duplex or performing "silencing," one should evaluate the true causes of a sound that is not well "composed" (old strings, damaged bridge, etc....).

Now I understand why for about 1/3 all the strings of the duplex scale are resting on felt!

I have a 1950s Steinway M and I discovered that the duplex scale of the central choruses is not tuned with the respective strings, but increases by half or a whole tone (meaning at the octave). Despite the backstrings not visibly increasing the timbre, I nonetheless notice that something is out of tune, and I have proof when I isolate the section. I wonder if it might be possible to loosen the strings and reposition the duplex plate at the right point.

I would have it checked by a specialized technician

on a Steinway one perceives some "chirping" sounds, how can I eliminate them? thanks.

You can try inserting some felt "knights" (felt dampers/wedges) beyond the hitch pins. However, you will have a bit less resonance. Perhaps you will avoid the noise. In any case, it is first appropriate to strike the strings at the bridge with a brass rod to ensure perfect adhesion. It is also necessary to check the tuning of those hammers and the perfect leveling of the courses. Also check the condition of the hammers. A hammer that is too grooved, especially in the high notes, causes a "dirty" sound. If then, as a remote hypothesis, the hammer rail had been shaved without respecting the original shape of the hammers (diamond-shaped for Steinway), especially if rounded in the high notes, the sound would become quite imprecise.