Frequency modulate 18KHz carrier with 3KHz audio signal.

[TimJohnson]

I want to frequency modulate an 18KHz carrier with a 3KHz audio signal. Can Dexter (or any other tool) do this?

Why?
Here is why.
I want to implement a poor man's sound projector. This is a device that can project sound across a room. The listener hears the sound from a direction other than the true source. Practical applications include "surround sound" without physically placing speakers all around. Targeting a single or small group of users in a crowd without sending the message to the whole crowd.

Current commercial sound projection systems cost upwards of USD $3,000.00 and use non-standard audio components including high-voltage pizeoelectric crystal transducers that put out a frequency modulated carrier of 200KHz with a 20-20KHz audio signal. This gives high fidelity, but at high cost.

I don't need high fidelity so a 1-6KHz audio signal is enough. Most of the power will be in the 3KHz +/- 1KHz frequency range. Supertweeters that can handle 200 watts at 30KHz can be purchased for $10.00. Unfortunately, cheap amplifiers are hard pressed to handle even 20KHz (someone tell me if the know of a "cheap" [under $100] amp that can handle 30KHz or more, please). All I need now is a way to modulate a high frequency (17-30KHz) carier with a 3KHz audio signal.

Can Dexter do this?
Is there another product around that can?
Thanks to everyone in advance for your help.
I will let you all know what develops.