B&C Speakers 21 SW 152

A 21" from B&C's range designed for high-energy infra applications

With the 21SW152, B&C offers a 21" speaker focused on "infra-bass," designed to meet the demands of modern sound reinforcement systems: large excursion, high thermal power handling, and efficiency suited for large enclosure volumes. Its positioning clearly targets large capacity sub/infra enclosures where massive acoustic pressure, stable response at high power, and reliability compatible with touring or fixed installations are required.

Intended uses and target users

The B&C 21SW152 is aimed at sound professionals, enclosure manufacturers, integrators, and service providers designing 21" subwoofers for clubs, festivals, concert halls, and large-scale installations. It is particularly relevant if your specifications require solid reproduction below 40 Hz, pronounced physical impact, and good control at high levels, whether in mobile stacks or fixed systems.

With a recommended enclosure volume of 190 liters and a tuning at 33 Hz, it naturally suits bass-reflex designs oriented towards infra bass. The provided parameters (Fs 32 Hz, Qts 0.36, Xmax 15.0 mm) indicate a balanced approach between low-frequency extension and control, with excursion capacity adapted to heavy demands.

Design and performance: what makes the difference in the field

Power handling and stability under intensive use

With 4000 W AES at 8 ohms, this 21" targets configurations with generous and continuous amplification. The AES standard, used to express a "realistic" power rating for audio use, helps to size a coherent system (amplification, filtering, limiters) to preserve longevity under performance conditions.

Large voice coil and Neodymium motor

The 6.0" (153 mm) copper wire voice coil contributes to thermal robustness and maintains dynamics as levels increase. The neodymium magnet keeps weight down while providing a powerful motor structure, which is a tangible advantage for touring enclosures and systems requiring a good power-to-weight ratio.

Excursion and reinforced mechanical components

The Xmax of 15.0 mm is combined with a triple roll suspension to handle the large excursions typical of infra frequencies. The radial cone features a waterproof treatment (front and back), useful when the equipment is exposed to transport stresses, humidity, or varying conditions. The double siliconed spider completes the assembly by promoting mechanical stability and repeatability of behavior at high levels.

Technical specifications

Rackable	No	Type	Speakers
Category	sound reinforcement accessory

Brand / Model	B&C 21SW152	Magnet	neodymium
Nominal diameter	21" (53 cm)	Suspension	triple roll
Nominal impedance	8 ohms	Cone	radial, waterproof treatment front/back
Power handling	4000 W AES	Spider	double siliconed
Sensitivity	96 dB (1 W / 1 m)	Total diameter	547 mm
Frequency response	30 Hz - 1 kHz	Height	261 mm
Fs	32 Hz	Weight	18.5 kg
Qts	0.36	Recommended volume	190 liters
Xmax	15.0 mm	Recommended tuning	33 Hz
Voice coil	6.0" (153 mm), copper wire