Date: August 15, 2000 at 11:26:33
From: Rob Mort, [ppp47-stgermain.isdnet.net]
Subject: Motional feedback

Does anyone have any practical experience with design of amplifier circuits for a motional feedback subwoofer? I cannot find any reference to such speakers on this site or any of the links quoted. This method promises many advantages - small size, crisp response compared with reflex designs, low frequency and high linearity. I am considering constructing a design from an article in Electronics & Wireless World magazine from 1997 which uses a second voice coil on the driver as a sensor. Has anyone else built this design? The circuit does not seem to be optimised - I am looking for alternative approaches. Opinions & views on motional feedback in general would be appreciated.