Audio Systems: A solid-state loudspeaker?, frequency transducers, sensitive drivers

Question
Hi:

Is there such a thing as a solid-state loudspeaker?

A solid state loudspeaker can directly convert electricity to sound without using a diaphragm.

Is this possible?


Thanks,

Green

Answer
Yes. Not strictly so; but they are calles such by some people.  The most common are piezo electric speakers. Mostly they are made by Motorola and many off-shore makers from China, Korea, Hong Kong and such.

They are very common in PA and professional systems.  They are mostly high frequency transducers and are commonly used as tweeters in 2-way and 2-way systems.

Also, there are some planar speakers that use large, flat diaphrams that are drive by piezo or other voltage sensitive drivers tied to the flat panel.

If you have some reference or who is telling you these things I can direct you more specifically as the body of loudspeaker inventions and types, sizes, applications and such  is very, very broad.

Best,
C

PS: There are a number of projects at various university labs looking a point source transducers of various kinds; some using solid-state stuff, some using other means.  You might find some interesting projects at MIT Media lab; you can google their projects easily at media.mit.edu and so on.