It's passive not active. Active subs have built-in amplifiers, passive ones don't. Active subs are better.
Its "bass" extension only goes down to 60Hz. Most floor-standing speakers (and a few stand-mounters) will go lower than that. My own main speakers go down to 34Hz (my sub goes down to 26Hz).
The SW-1 is not really much of a sub-woofer, to be honest.
The Carnival 2 from Mordaunt-Short is a punchy and substantial speaker which is ideal for bookshelf mounting but comes into its own when you place it on a high-quality stand. You'll be surprised the big, full-spectrum sound it produces rivaling the performance of larger, more expensive speakers...
Developed as a dedicated center speaker, the Mordaunt Short Carnival 5 is designed for best dialogue dispersion. Ideal for entry-level 5.1, 6.1 or 7.1 home theatfree er set-ups, the Carnival 5 is magnetically shielded for interference placement directly on top of or close to TVs.
The Mordaunt Short Carnival 1 is an extremely compact speaker which is suitable for stereo set-ups and is ideal for smaller rooms. It handles an impressive 80 watts and so punches well above its weight, bringing music to life...
The Mordaunt-Short Carnival 6 is an elegant floorstander which is far more potent than its elegant appearance might suggest. The Carnival 6 handles 120 watts and offers awesome low-level performance producing a refined and detailed sound.
The Mordaunt-Short Carnival 3 is a dedicated effects speaker designed for the most demanding home theater set-up, the Carnival 3 features two drive units mounted in the opposing faces of the dipole enabling a full surround sound effect...
Aviano 6 features two 6½" mid/bass drivers for explosive results from music and movies alike. Computer-modelled bracing design and driver supports reduce distortion and vibration to extremely low levels whilst adding significantly to cabinet rigidity...
The Mordaunt Short Carnival 7 is a compact class AB subwoofer that is capable of delivering an impressive 65 watts. Carnival 7 is ideal for home theater set-ups and deals commandingly with low frequencies...
Developed as a dedicated center speaker, the Mordaunt Short Carnival 5 is designed for best dialogue dispersion. Ideal for entry-level 5.1, 6.1 or 7.1 home theater set-ups, the Carnival 5 is magnetically shielded for interference free placement directly on top of or close to TVs.
Aviano 2 features a larger 6½" driver enabling noticeably increased dynamic headroom. Oozing more presence than has ever before been possible from such compact cabinets, Aviano 2 offers a fantastic combination of value and performance...
Mordaunt Short Performance 6 loudspeaker, Audio Merchants