Most speaker cabs have 2 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 known as "daisy-chaining."

Without going into a drawn-out technical explanation, here's what happens:

When you connect speakers of the same impedance, divide the rating of the individual speakers by the number of speakers to get the overall impedance load. For example, two 8-Ohm speakers will result in a load of 4 Ohms (8 Ohms ÷ 2 = 4 Ohms). Daisy-chaining four 8-Ohm speakers will result in an overall impedance of 2 Ohms (8 Ohms ÷ 4 = 2 Ohms).

Daisy-chaining speakers of different impedances results in strange impedance values, and difficult calculations to determine what the value is. It also results in uneven distribution of power between the speakers. I would not recommend daisy-chaining speakers with different impedances.

When daisy-chaining speakers, you need to be careful that the resulting impedance is equal to or greater than the minimum impedance rating of the amplifier (see our section on Impedance matching).