Robert Estrin - piano expert

What is a Tension Resonator System?

Learn about this unique piano technology

In this video, Robert talks about a technology developed by Mason & Hamlin Pianos back in 1902. The technology is still unique to that piano brand and not found on any other piano.

Released on May 25, 2016

Share this page!
Post a Comment   |   Video problems? Contact Us!
DISCLAIMER: The views and the opinions expressed in this video are those of the author and do not necessarily reflect the views of Virtual Sheet Music and its employees.

Video Transcription

This is Robert Estrin at and The question today is, "What is a tension resonator system?" That's a fancy term, isn't it? Well, we're going to break it down for you. Tension resonator system is sometimes dubbed "the spider," And it's actually, if you had to guess right now, you're probably wondering with bated breath what I'm going to say next. It's actually a technology developed by Mason & Hamlin. This concert grand, built in 1902, has the tension resonator system. Why is this so significant? Well, to understand the value of the tension resonator system technology, first of all, you have to understand something about the nature of how pianos produce their tone, then I'll get into what the tension resonator system is.

The piano produces its sound with a very thin membrane of wood called the soundboard, and without the soundboard, even a massive piano like this nine foot, four inch Mason & Hamlin, you wouldn't hear across the room. That's right. It's the potential energy of that soundboard. What creates the potential energy is that it's actually built under tension, creating a slight upward arching referred to as "crown," and that is what is essential in a piano. And even brand new pianos vary one to the next in the architecture, in the amount of crown, and how it imparts the tone.

A piano where the soundboard flattens out and there's no longer crown has a dead sound. The tones don't last, so you'll play a note, and it's gone in a matter of seconds, where a piano with excellent crown will sing. The tone will last a long time. So it's very desirable.

Well, how do companies assure that crown is maintained over the years? Well, one way is to have very massive inner and outer rims, as this Mason & Hamlin piano has, but they go even further. If you look underneath a Mason & Hamlin piano, they have this spider-looking device. It's actually made out of metal, and it supports the rim at several points. So that's why these instruments, even from a hundred years ago, can still have vibrant soundboards with excellent crown, because the massive rim, combined with the tension resonator system helps to keep the crown longer than in regular pianos. It's a tremendous patented technology that only Mason & Hamlin pianos have, and next time you see a Mason & Hamlin, climb underneath and check it out. It is a sight to behold.

Thanks for the great questions. Again, Robert Estrin at and
Post a comment, question or special request:
You may: Login  or  
Otherwise, fill the form below to post your comment:
Add your name below:

Add your email below: (to receive replies, will not be displayed or shared)

For verification purposes, please enter the word MUSIC in the field below

Comments, Questions, Requests:

Fulvia * VSM MEMBER * on May 25, 2016 @6:09 am PST
Very interesting. I wonder why other manufactureres have not adopted this "spider" ?
Robert - host, on May 25, 2016 @11:45 am PST
Mason & Hamlin invented the technology and hold the patent for the Tension Resonator System.
Questions? Problems? Contact Us.
Norton Shopping Guarantee Seal