Even today, Motional Feedback is used by High End audio designers.

Even today, at the age of 86, Piet is an active member of MFBfreaks.com, the home of Motional Feedback collectors.

Motional Feedback (MFB) is the name of an active High Fidelity loudspeaker system which was developed by the Dutch Philips brand in the early 1970s.

The SQ-65 featured a motional feedback (MFB) circuit, a patented development by Lux that incorporates the motion of the speaker cone into its feedback control system.

Although the Motional Feedback technology had been experimented with for several years, Philips was the first company to successfully create a working prototype and create a commercial product line of loudspeakers and equipment.

Product Manager of the Philips High Fidelity group, Piet Gouw, was responsible for the launch of most of the Motional Feedback loudspeakers and other High Fidelity equipment.