Frequency Reading (Hz)

Many people ask me about the Hz (Hertz) in my posts so I decided to give a brief explanation.

Every object vibrates when subjected to an external excitation, a table tennis racket is no different. The excitation produces several modes of vibration, each with its own deformed shape. In a TT blade the two modes that matter the most are the 1st (flexural mode – first pic) and the 6th (membrane mode – second pic). To measure the first mode specialized equipment is required, however the membrane mode is related to the pitch we hear when we bounce a ball on the blade, so it is easy to measure. This can be done by using a spectrum analyzer app on your phone. But how does this relate to TT blades? Well, a stiffer material will vibrate at a higher frequency, and generally speaking, stiffness is related to speed. So, higher Hz -> More stiffness -> More speed. Of course this is just a general assumption, many other variables play a part in the speed of a blade, but this method gives a nice reference point, especially when comparing blades with a similar structure.