I went from jbl pro performer sats with a slave subwoofer to a pair of Mirage frx 7 floor standing. I now relalize that I have BASS with movies and music. I am looking to add more BASS with a sub. I have mirage center , infinity inwalls as rears, sony stre845 receiver, and toshiba sd1710 dvd player. My room is 20 X 15. I would prefer( actually my wife would) a smaller size if poss. I need to stay under 500. 75% ht and 25% music. Help please! Happy Holidays!