technical specifications

M421Product Group: Touring Class System Type: Subwoofer, Quad 21"

pRoDUct DescRiptionThe M421 sets a new standard for low distortion, high impact, bass reproduction. The M421 has a continuous power handling capactiy in excess of 12,000 W (24,000 W instantaneous peak) and a measured peak output of 143 dBSPL at 4m within its operating band. With a flat response from 20 to 100Hz and a total weight under 490 lbs., the M421 delivers an unprecedented level of low frequency engery for its size.The revolutionary design features four 21” long excursion neodymium motor transducers with 6” voice coils that exhibit near linear BL product through the entire range of cone motion. The drivers are configured in an isobaric connection and coupled to an FEA optimized acoustic transformer. With integrated handles, casters, skids, travel dolly, and optional flyware, the M421 is the most versatile and powerful sound reinforcement subwoofer to date.

• Touring Sound Reinforcement• House of Worship• Theatrical Sound Reinforcement• Stadiums and Arenas• Theme Parks • NightClubs and Concert Halls

applications

The enclosure is constructed of multi-ply void-free birch hardwood plywood and is coated with a weather and wear resistant ProCoat™ polyurea hybrid finish. Components in the front of the enclosure are protected by a flat grill made from perforated 11 gauge steel that is coated with heat cured epoxy powder. All rigging and hardware is weather protected with a heat cured epoxy powder coat finish.

constRUction

• High Efficiency, SPL• Integrated Casters and handles• Integrated Locking Skids• Weather and Wear Resistant

featURes anD aDVances

peRfoRmance paRameteRs physical pRopeRtiesSystem Type

Frequency Response-10dB

+/- 3dB

Sensitivity

LF

Maximum SPLLF

Power RatingsLF 1 - AESLF 2 - AESLF 2 - AESLF 2 - AES

(4) 21" Cone Transducers, 6" Voice Coil, Neodynium Motor

3000W @ 8Ω

3000W @ 8Ω

3000W @ 8Ω

3000W @ 8Ω

111dB @ 2.83V 1 m

(cont. / peak)

Weight

Dimensionsinches

centimeters

Enclosure Material

Hardware

Finish

TransducersLF

Connectors

Optional Accessories

5/8” Multi-ply Birch Laminate

Neutrik™ NLT8**required for maximum output due to connector maximum voltage rating.

(Black is standard, White and / or Custom Colors Available)Procoat™ Polyurea-Hybrid Weatherproofing

23.10 h x 73.40 w x 44.00 d 58.67 h x 186.43 w x 111.76 d

486lbs / 220kg

Integrated Locking Skids on Two FacesInstall Version Available w/o Casters and Handles

149dB / 155dB calculated 1m ground plane143dB measured 4m ground plane pink noise processed 20 - 85Hz

16Hz - 120Hz20Hz - 85Hz

Subwoofer, Quad 21"

M421 Dolly, M421 FlyKit, Mb421 Rigging Frame

Dimensional illUstRations

aRchitects anD engineeRs specificationsThe subwoofer loudspeaker system shall incorporate four 6" (152.4 mm) voice coil, long excursion neodymium motor, 21" (533.4 mm) diameter transducers, mounted in an isobaric pair configuration and coupled to an FEA optimized acoustic transformer for maximum low frequency response. The horizontal and vertical beam width for a single unit shall be omni-directional in the operating band. Directional characteristics can be achieved with an array of multiple cabinets.

The unprocessed system frequency response shall vary no more than ±3 dB from 20 Hz to 85 Hz measured on axis. Each transducer shall produce a Sound Pressure Level (SPL) of 111 dB SPL at a distance of 1 meter with an electrical input of 2.83V, and shall be capable of producing a maximum peak output of 143 dB SPL on axis at 4 meters.

Each low frequency transducer shall handle up to 2000 Watts of amplifier power (per AES Standard AES2-1984-r2003) and shall have a nominal impedance of 8 Ohms. Certain configurations of multiple cabinets will facilitate even higher capacities.

The loudspeaker enclosure shall have a maximum weight of 486 lbs.(220 kg) and shall measure 73.40" (1864 mm) wide, 23.10" (586 mm) in height, and 44" (1117 mm) in depth. The structure of the enclosure shall be constructed of 12-ply void-free birch hardwood plywood and shall have a weather and wear resistant ProCoat(tm) polyurea hybrid finish.

Input connectors shall be two Neutrik NLT8 locking connectors, each connector is wired in parallel. Optional 3/8"-18 UNC threaded mounting/suspension points can be provided upon specification. Components in the front of the enclosure are to be protected by a grill made from perforated steel that is coated with heat cured epoxy powder.

The high performance subwoofer loudspeaker system shall be the McCauley Sound model M421.

23.45595.50

0.256.35

4.0" Swivel Castors

73.801874.52

44.001117.60

49.331252.99