Need a suggestion for manufacturers of an ultrasonic frequency sound device

Thought I would sign up here to see if someone would be able to offer me some direction. Would anyone be able to suggest a manufacturer of equipment that is capable of producing sound waves of the infrasonic type (below 20hz) as well as ultrasonic (above 20k)?

I know this is an off the wall question but I didn't really have any idea of where to start. If not, a suggestion as to where else I might look for this kind of information would be helpful.

This would be in relation to materials testing.

Thanks

 

A sine-wave signal generator, wide bandwidth audio amp and supertweeter and subwoofer.

All of these can be found used on ebay.

Steve N.
Empirical Audio