School of Physics Lecture Demonstration Manual

Wf-3 Helmholtz Resonators

Published: Wednesday 15 March 2006 - Updated: Thursday 31 March 2011

Aim

To demonstrate a Helmholtz resonator, i.e. an acoustic device that exhibits mechanical resonance with small damping.

Apparatus

Diagrams

Click on pictures to enlarge.

Helmholtz Resonator Diagram

Description

 A Helmholtz resonator consists of a volume V fitted with a short open neck N. The air in the neck functions like a piston and the air in the cavity as a spring.
 The frequency f, of the free vibrations of the air in the neck is given by
 N = (c / 2 Pi) * SQRT (S/lv)
 

Safety notes

Electrical safety 

Maintenance 

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