James Sweet wrote in news:cX4Mh.11668$e47.4988
@trnddc05:

The problem is that galvos have
physical mass and inertia, so the characteristics are quite different
than that of a vector monitor.

This was my initial thought: too much mass, too much inertia, slow
response.

But loudspeakers are really "linear galvanometers", and their frequency
response is quite good. Might be fun to figure out how to change a mirror
angle with an old speaker.

Old hard drives used a moving-coil in a magnetic field to scan the sensor
across the disk--another opportunity to turn an old part into an
interesting experiment.