need help or advice for constructing a powerfull signal generator.

[username]

i need help building a powerful signal generator or amplifier that can produce a clear sine wave signal from 1 to 20,000 hertz. i have an experiment i plan on doing involving infra-sound, and maybe later for powering a large acoustic transducer. the experiment involves using car sub-woofers, the "bling bling gangsta" ones that operate at 1000 watts then putting them in a hermetically sealed enclosure about 3/4 the size of a closet so that i can observe the effects of infra-sound. as you may or may not know the amplifiers they make for car audio don't work well below 20 hertz, in fact i tested this and at 10 hertz the signal was distorted and the amplifier overheated immidiatly, i already have the sub-woofers and the enclosure. i don't want to spend thousands on an amplifier that can do this, is there any way around this? i was thinking of getting a variable transformer then rectifying its output and using a signal generator to drive a IGBT so that it converts the DC from the variable transformer into a sine wave corresponding to the voltage output of the variable transformer and the intensity and frequency of the signal generator. however i don't know if that will work or not (i don't know very much about transistors so im probably wrong). i need advice on this. help will be greatly appreciated!

[Arex_x]

Hello.
A bit late answer.

From what I know about IGBTs , (not much really. Have newer used them.) they are not particularly linear.
They are from what I understand mostly used for switching. Mostly.
If I come across something like what you are looking for I'll try and remember to post it here.