A little reality. Three strings each putting out 100dB equals 104.7dB. Two strings each putting out 100dB equals 103dB.
Original Message:
Sent: 09-29-2025 11:46
From: Alan Eder
Subject: Upright Soft Pedal System Function
The "una corda" or "shift" pedal on grands does attenuate the volume of sound produced but, if working optimally, should accomplish more than just a reduction in decibels. Introducing parts of the hammer strike point that are not compacted like the string cuts in the rest position produces different tone, ideally in gradients. Most classical pianists rely heavily on this to produce the most expansive total pallet possible from a given instrument. Pianist Frederic Chiu has spoken extensively about this in forums geared towards piano technicians.
------------------------------
Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
------------------------------
Original Message:
Sent: 09-28-2025 20:52
From: Geoff Sykes
Subject: Upright Soft Pedal System Function
Wim --
I don't think it was designed for that purpose, but I use it for that purpose myself, on pretty much every upright I see, every time. Very useful for that, indeed.
What I learned was that original grand piano design had a single pedal for sustain, and later a second pedal, for soft, or unacorda, was added. (That second/left pedal is called unacorda because at the time pianos only had two, not three strings. Shifting the hammers over from bichord, two strings, to unacord, one string, made for a very large, 3db, change in loudness. Today, with the unicorda pedal shifting from a trichord to a bichord only makes for a 1-1/2db loudness change. Hardly noticeable.), Now that third, middle pedal, as I was told, is an American invention of no defined use. It was added purely as a marketing feature so that salespeople could say that American made pianos were better because they had a third pedal. (They could go up to 11. 😁) As we all know, that middle pedal gets used for many things depending on manufacturer and model. Sometimes it's bass damper lift. Sometimes it's sostenuto. In uprights it can get really weird. Most of the time it's for a practice rail but I've seen older ones where the right and middle pedal do exactly the same thing. Sometimes they do so by using two separate connecting rods. Sometimes the two pedals are simply tied together at a single connecting rod. I've even found some where the middle pedal exists but isn't hooked up to anything other than a spring so it feels like it's doing something.
------------------------------
Geoff Sykes, RPT
Los Angeles CA
Original Message:
Sent: 09-28-2025 18:16
From: Wim Blees
Subject: Upright Soft Pedal System Function
In my opinion, the soft pedal on an upright piano was only developed for us technicians to check for sluggish hammer flanges. Push the right pedal to disengage the dampers, and then slowly press and release the left pedal. When the hammer rail comes back, it will instantly identify any sluggish hammer flange. lol
Wim
Original Message:
Sent: 9/28/2025 5:43:00 PM
From: Geoff Sykes
Subject: RE: Upright Soft Pedal System Function
My ¢¢ --
I have never been able to make the soft, or left, pedal do anything that I can hear on either an upright or a grand. On the other hand, I know I don't play well enough to make it do what it's supposed to do in the first place. When I hear good players, on either an upright or a grand, use it I can definitely hear the difference. The customers that I have that have mentioned their inability to hear a difference, uniformly don't have the skill to play softly in the first place. Many mistake it for a way to make the piano overall quieter, like when using a practice, or middle, pedal on an upright. It's easy to spot a customer who uses it this way on a grand, as the hammers will start to wear flat instead of developing grooves. As Alan suggested, if what the customer wants is to use it like a practice rail, and the piano does not already have one, then you need to install one as an add-on, like he described. If they want to use that pedal to make a phrase they are playing more quiet then they just need to learn how to play more quietly in the first place, and then add that in. It's deliberately a subtle difference to start out with, but knowing how and when to use it helps.
------------------------------
Geoff Sykes, RPT
Los Angeles CA