The default/native operating mode is 20 Hz with all ports open. The 20 Hz mode provides the most muscular and powerful presentation at the most common bass frequencies and offers usable in-room low end reproduction down to about 17-18 Hz.

If one port is shut off and the Subwoofer Tune on the amplifier is set to 16 Hz, the subwoofer delivers usable low-end reproduction down to about 13-14 Hz. There is a slight decrease in maximum output power at the more common bass ranges in this regard when the deeper 16 Hz mode is selected, but many enthusiasts find this trade-off worthwhile when diving deeper into the infrasonic region for DVDs and certain pieces of music (such as an acoustic pipe organ).

When all ports are closed and the Subwoofer Tune on the amplifier is set to ‘Sealed’, the subwoofer begins to drop off around ~32 Hz and has a wide/gradual roll-off profile. This less steep roll-off is often an excellent match for the acoustics of a smaller room with a lot of ‘room gain’ (or rising bass response). In such a smaller room, the Sealed mode can often reveal a usable low-end response down to 15 Hz or even deeper!

In short, SVS’s variable tuning options offer the enthusiast ultimate flexibility in tuning and deep extension to meet the demands of varying room sizes, playback levels and listening applications.