Vibration analyser takes the ear out of speaker development

Citation

(1998), "Vibration analyser takes the ear out of speaker development", Sensor Review, Vol. 18 No. 2. https://doi.org/10.1108/sr.1998.08718baf.009

Vibration analyser takes the ear out of speaker development

Vibration analyser takes the ear out of speaker development

Keywords Acoustic, Ometron, Vibration

Ometron's VPI 4000 vibration pattern imager has transformed acoustic design from a "voodoo rite" into a science, according to top US audio speaker company Mackie Designs.

Although conceived as a development tool for the world's leading automotive and aircraft designers, the VPI 4000 has been used by Mackie Designs in its acoustic laboratory as part of a development programme to find the ideal sound system.

Specialising in developing speakers for recording studios, Mackie Designs turned to the VPI 4000 for help in transforming its theoretical ideas for an active monitor ­ an internally-powered rather than a passive speaker ­ into a precise, powerful and completely neutral sound system.

Instead of employing the traditional highly-subjective "tweak and listen" approach to speaker design, Mackie development engineers used the VPI 4000's scanning laser vibrometry to give a clear picture of exactly what was happening on the surface of the speaker.

Mackie Designs' chief executive Greg Mackie compares the VPI 4000's use of fast Fourier-transform vibration analysis to develop his company's HR824 active monitor with that of the oscilloscope in electronic design.

"The VPI 4000 has proved its worth in selecting and optimising the HR824's transducers", he says. "It produces accurate, instant images of the vibrations that occur in a transducer dome or cone at any given frequency."

The VPI 4000 uses a low-power laser to scan the surface of a vibrating component from a range of a few millimetres up to 200 metres or more. It produces full-field vibration maps at selected frequencies within seconds through fast-Fourier transform analysis of the surface data.

Vibrating surfaces can be unprepared and poor reflectors, and they can also be complex in shape.

For further information contact: Ometron Division, Image Automation Ltd, Kelvin House, Worsley Bridge Road, Sydenham, London SE26 5BX, UK. Press contact: Richard Atkinson on +44 (0)181-461 5566.