Dear Rkerv: I agree with Kthomas: Velodyne.
My advise is for two of them not only one: two units are necessary for not to loose the stereo effect, remember that the low bass rerpoduction is not only the fundamental frecuencies but the harmonics too.
Two DD-15 will be out of your high budget, but you can buy ( second hand ) two HGS-15 or two HGS-12 for that money. The Velodyne HGS series have the same sound reproduction performance than the DD series, the differences between them are the easiest way to blend the subwoofers with the main speakers: with the DD series you can do it in an very profesional and cientific way and you can " tailored " the in room response and with the HGS you have to do by " ear ".
Regards and enjoy the music.
Raul.