The McCauley M421 is a quad 21-inch subwoofer built for uncompromising ultra-low frequency reinforcement in the most demanding environments. Four high-excursion 21-inch neodymium transducers with 6-inch voice coils deliver immense headroom and tightly controlled response, reaching confidently into infrasonic territory. With a frequency response of 20–85 Hz (-3 dB) and usable extension from 16–120 Hz (-10 dB), the M421 produces authoritative, musical low end that retains definition at extreme levels.
Engineered for scale and reliability, the M421 achieves up to 143 dB continuous (155 dB peak) at 1 metre, pairing seamlessly with modern high-output amplification thanks to robust power handling in excess of 12,000 W continuous (24,000 W peak). Its design supports deployment as a single high-impact enclosure or in larger arrays where uniform coverage and consistent low-frequency impact are essential. Built to tour-grade standards, it offers the output, clarity and resilience required by professional rental, touring and premium fixed installations.
Choose the M421 when you need extreme low-frequency extension and clean, controlled impact for arenas, festivals, large-format clubs and high-end installs.
Includes
- McCauley M421 Quad 21-inch Subwoofer | Ultra-low bass
STAGE9.3.100.000


