I designed active sub-woofer systems using postive feedback to achieve a virtual negative DC resistance in the voice coils so as to maximise cone excursion control. The idea was developed in the 1950s and my designs were based on schemes provided by Peter Roberts. I expanded on the principle of cone excursion control using neodymium-boron magnets with 10 times the flux density of the ususl ferrite versions.My biggest sub-woofer system was a 1500Liter twin 18" unit tuned to 6 Hz–perfect for cathedral organ pedal bass and synthesizer reproduction and of course for handling Telarc's CD of Tchaikovsky's 1812 overture at full belt; those canons bottom out most woofers!I designed a smaller system as a TV monitor tuned to 30Hz and with a gutsy sized transformer for punchy bass.

Responsible for production and customer orders.

To develop high quality audio components, testing the theory against the practise and often looking for weaknesses in the design.