Passive vs. Active Speakers

Passive speaker cabinets are cabinets that must be powered with an external amplifier.
Active speaker cabinets have a built in amplifier.  They do not require an external amplifier.
Every Seismic Audio cabinet, with the exception of the RSG Series, is passive and requires an additional power amplifier.
The RSG Series is the only active Seismic Audio speaker cabinets.

Daisy Chaining

Most Seismic Audio speaker cabinets have two jacks on them.  One jack is used for connecting the speaker to the amp and the other can be used to connect a second speaker off the first.  This process is commonly referred to as "daisy-chaining."  It doesn't matter which jack is used for either connection.

When you daisy chain speakers, this is what happens:
If you connect two 8 ohm cabinets together, it cuts the ohm load in half.  Therefore, two 8 ohm cabinets hooked together would be a 4 ohm load.  If you connect four 8 ohm cabinets together, it would be a total of 2 ohms.
It is not recommended to daisy chain two cabinets with different ohm loads. Example: Do not connect a 4 ohm cabinet with a 8 ohm cabinet.  It will result in an uneven power distribution between the two cabinets.
Be sure to check the minimum impedance rating of your amplifier before daisy chaining your speakers.  Dropping below the recommended ohm load on your amplifier can result in damaging to the amp and or speakers.