Frame, Back Posts, Inner Rim

Function and Construction

• There are two types of support in a Yamaha grand piano: the back posts radiating diagonally from the centre, and the curved inner rim. The soundboard is attached to the top of the curved inner rim.
• The frame, back posts and inner rim act together as a single unit to support and withstand the combined tension of the strings.



Major Points

• The proper matching of the back posts, inner rim and frame together with the soundboard and strings is of highest priority in a Yamaha grand piano. Working together, they create a synergetic effect.
• The casting of the frame uses the latest V-process casting technology, responsible not only for the strength of the Yamaha frame, but also a very accurate reproduction of the pattern and a smooth surface finish.
• The material used for the support members has been carefully selected, taking into consideration not only their strength, but also how their resonance values match with the strings' vibrations.
• The back posts feature a radical design. The centre of the assembly is securely fastened to the "tone collector", joining the wooden support members and the frame into a single unit.
• The tone collector acts as an acoustical mirror, that collects and reflects the vibrations into the tone producing area of the grand piano.
• The wooden support members have been firmly fastened together with dovetail joinery, a most strong and durable construction method.