Uses no active components (transistors, IC's, tubes) and needs no power supply (AC, DC, battery) to operate. The crossover in a typical loudspeaker is of the passive variety. Passive crossovers consist of capacitors, inductors and resistors.
Most domestic 'Hi Fi's' of lower power use what is known as a 'Passive' crossover system, where the frequencies are split after the signal has been amplified.