Take a hard look at the 1.HSU STF-3... Flat to 25 HZ bass, and an excellent sounding unit. 2. SVS PB1-ISD... Flat to 20 Hz, slightly bigger than the STF-3, which gives the deeper bass. 3. SVS 20-39 PCi ... flat to 17 Hz, much bigger than either, though the size is in its 39 inch height...

All are $599... all are excellent !