Reflex SB121

High power sub bass enclosure
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Product Overview

The Reflex SB121 is a high power sub bass enclosure.

• Components: 1 off 21″ cone drivers

• Directivity: Omni-directional

• Max SPL: 137 dB

• Weight: 55 kg

Reflex SB121 Product Description

The Reflex SB121 is a high-power sub bass enclosure designed to operate over the 34 – 95 Hz pass band. The Reflex SB121 has a range of applications within both touring and fixed installation. It may be combined with products from the iQ or MQ ranges within fixed installation, or used as a ground stacked infra sub bass for larger Optima array touring systems.

The cabinet houses a single 21” long excursion cone driver with neodymium magnet structure which is 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 four handles and the option of rear panel mounted castors. The cabinet base has polyethylene runners and the cabinet top panel housings to aid cabinets when stacked 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 either two parallel linked Neutrik NL4 MP connectors on the rear panel, allowing a direct connection from an Eflex Q20 system amplifier. An additional Neutrik NL4 MP on the front grill allows connection from an Eflex Q20 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 two SB121 enclosures per output channel.
Made In Britain 300px WHT

Reflex SB121 Specification

1 off 21″ cone drivers

Frequency response:
34 – 95 Hz

Sensitivity: 1w/1m (Peak):
99 dB (137 dB)

Power (RMS/Peak):
1700 w (6800 w)

4 ohms


Operation mode:
Active pass band

4 off Neutrik NL4 MP

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

Weight (Packaged): 
55 kg (59 kg)

Dimensions (mm): 
700w x 590h x 695d

Reflex SB121 Downloads

Specification Sheet

Reflex SB121 Elements

Reflex SB121

Ground Stacked Bass


The Reflex SB121 is a high power single 21″ bass enclosure.

Eflex Q20

System Amplification


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