4 Ohm speakers will accept more power than 8 ohms, about twice as much. Speakers with lower impedance can handle higher volumes and provide better sound quality because they're able to move air without getting too loud for your room's volume level; this means you won't need any extra amplification or enclosure help from external amplifiers which saves space in your pedalboard! The way we connect our series-wired stack is: 18 volts delivered through one terminal produces equal voltage drop across both wires connected together at 20Kohm terminations.