On Wed, 26 May 2004 22:10:50 GMT, "Richard Tomkins"
wrote:

Has any manufacturer ever designed/built a loudspeaker that reversed the
functions of the voicecoil and permanent magnet, such that the permanent
magnet was attached to the speaker cone and the electromagnet was the
stationary magnet?

Would add substantial moving mass which is usually unwanted.

What about having the voicecoil on the outside rim of the speaker rather
than on the inside? Has this ever been done?

Most dome tweeters. Some have attempted this with larger drivers.

Instead of using a single voicecoil in the center, how about one on the edge
and one in the middle?

If you could control the drive in a coordinated way.

How about a dual voice coil, one being driven and the second providing
feedback like a closed servo loop?

Old hat.

Kal