Reflex SB221

High power sub bass enclosure
Previous slide
Next slide

Product Overview

The Reflex SB221 is a high power sub bass enclosure.


• Components: 2 off 21″ cone drivers

• Directivity: Omni-directional

• Max SPL: 143 dB

• Weight: 95 kg

Reflex SB221 Product Description

The Reflex SB221 is a high-power sub bass enclosure designed to operate over the 34 – 95 Hz pass band. The Reflex SB221 has a range of applications within both touring and fixed installation. It may be combined with MQ, or Optima range products within fixed installation or used as a ground stacked infra sub bass for larger Optima array systems.

The cabinet houses a pair of 21” long excursion cone driver’s with neodymium magnet structures which are loaded into a twin chamber band pass structure. The enclosure is manufactured from 18mm birch plywood and coated in a heavy duty polyurea finish. The cabinet front has a protective steel grill coated in a water-resistant powder coat finish which has an acoustically transparent filter medium bonded to its back surface. Each cabinet has eight handles and the option of rear panel mounted castors. The cabinet base has polyethylene runners and the cabinet top panel housings to aid stacking cabinets in vertical columns. Three cabinets in a vertical stack have the option of being used in a cardioid mode with the bottom cabinet inverted.

Electrical connection to the cabinet is via two parallel linked Neutrik NL4 MP connectors mounted on the rear panel, which allows direct connection from an Eflex Q20 system amplifier. An additional Neutrik NL4 on the front grill allows connection when a cabinet is inverted in cardioid mode.

All Inspired Audio products are designed as an integrated solution complete with system amplifier options from the Eflex range. The Eflex units provide DSP preset functions, networked software control of operating parameters and output drive power. An Eflex Q20 will drive one SB221 enclosure per output channel. 

NOTE: The SB221 cannot be driven by the Eflex Q5 or Q6 system amplifier.

Made In Britain 300px WHT

Reflex SB221 Specification

2 off 21″ cone drivers

Frequency response:
34 – 95 Hz

Sensitivity: 2.8 V/1m (Peak):
102 dB (143 dB)

Power (RMS/Peak):
3400 w (13600 w)

2 ohms


Operation mode:
Active pass band

3 off Neutrik NL4 MP

Wiring protocol:
Direct input/Link: 1+/1-

Weight (Packaged): 
95 kg (99 kg)

Dimensions (mm): 
1100w x 590h x 780d

Reflex SB221 Downloads

Specification Sheet

Reflex SB221 Elements

Reflex SB221

Ground Stacked Bass


The Reflex SB221 is a high power twin 21″ bass enclosure.

Eflex Q20

System Amplification


The eFlex range of advanced DSP amplifiers powers our entire product range.