What makes a Steinway different: Treble Bell

If you’ve ever been curious enough to look at the underside of a Steinway grand piano, you may have noticed a large metal piece that is shaped slightly like a witch’s hat.

This piece of metal is a treble bell. Some pianists will be unfamiliar with this addition to larger Steinway grand pianos and may wonder about its function.

Let’s find out more about what Steinway’s treble bell is and how it helps the largest grand pianos create that signature Steinway sound.

What is a piano’s treble bell?

A treble bell is present in the four larger models of Steinway grand pianos, including models B and D. Made from cast iron, the treble bell is an interesting shape, not unlike a cone.

The treble bell is affixed to the underside of the piano’s rim in a place called the ‘treble bend’ and is connected to the soundboard by means of a bolt.

Interestingly, while it’s called a ‘bell,’ which suggests it’s a sound-enhancing feature, the treble bell is actually designed to cancel out any metal vibrations caused by the piano’s frame.

How does a piano’s treble bell work?

The treble bell serves multiple purposes. Firstly, it ensures that longer grand pianos consistently produce exceptional sound by increasing the plate’s rigidity in the treble section. This is the most difficult part of the piano to get quality sound from, as the strings are the shortest, and the soundboard is the stiffest.

The treble bell pulls the frame down and pulls the rim in, allowing the soundboard to vibrate more freely. This arrangement goes a long way to providing a Steinway grand with that well-known crystal-clear bell-like sound in the treble. This system also helps the piano maintain its shape over time.

How a piano’s treble bell is constructed

A Steinway grand piano’s treble bell is constructed from superior-quality cast iron, which is moulded into shape.

The widest end of the bell is bolted to the metal plate, and the tapered end is connected to the soundboard using a vertical bolt, also known as a bell bolt.

How Steinway’s unique treble bells make for superior sound quality

This large yet hollow piece of cast iron is integral to increasing the rigidity of the plate and therefore allowing the instrument to produce a louder, more sustained sound that is characteristically Steinway.

The piano’s treble bell is closely associated with Steinway grand pianos as it is a crucial feature of our largest models. It is a vital addition contributing to the Steinway grands’ superior sound quality. This commitment to continuous innovation and improvement has ensured Steinway’s grand pianos have remained the most coveted in the world for over 150 years.


What is a treble bell?

A treble bell is a cast-iron piece of metal which is bolted between the soundboard and the frame of larger models of Steinway grand pianos. It offers support and contributes to the crystal-clear, bell-like sound in the treble.

Do you need to adjust a treble bell?

No. The only time a treble bell will need adjusting is if the plate is being reset or rebuilt. If any section of your piano requires rebuilding, we recommend you contact a professional, as a mistake could damage the instrument and cause it to lose its signature sound.
Contact our Piano Servicing or Piano Tuningteams if you require tuning, repairing, or replacement support.

What is the purpose of a treble bell?

A piano’s treble bell is used to provide additional rigidity to the treble area of grand pianos, which is not supported by wooden braces, unlike other sections of the piano. Smaller grand pianos and uprights do not require a treble bell.