Passive speakers require an external amplifier to drive them and are favored by professionals for their customizable sound and ability to pair with different amps. Historically, passive speakers have been the standard for live sound setups, offering flexibility in choosing the right amplifier to suit specific needs. Leading models include the Yamaha CBR series, JBL EON series, QSC K series (also available in powered versions), and Electro-Voice ELX series. These speakers are known for their reliability and sound quality, often used in medium to large venues where a powerful, high-fidelity sound system is required. Their flexibility and scalability make them popular in various live sound environments.