• BASSO21-A_front
  • BASSO21-A_HighAngleR
  • BASSO21-A_HighAngleL
  • BASSO21-A_side
  • BASSO21-A_rear


21" Direct Radiation Active Subwoofer

Compact 21" active subwoofer, with high output linear response from to 25Hz, for portable professional sound reinforcement systems and very deep LF demanding installations. Designed to operate as an “Infra” VLF extension of the rest of the BASSO Series subwoofers as well as a stand-alone subwoofer, ideal for the reproduction of deep-bass-heavy music styles and for AV and Broadcast applications.


BASSO Series models allow the user to choose the most adequate subwoofer for any given situation from within a family of products with common finish, design solutions and performance philosophy as well as shared rigging and transport accessories.
BASSO21-A is a high-density direct radiation subwoofer that brings the genuine 21’’ deep sound out of a very compact rugged cabinet, built with high quality birch 18 mm birch plywood, 2mm steel grille and IDEA Aquaforce wheather-resistant, durable coating.
This powerful, multipurpose subwoofer produces a clean linear audio signal that couples naturally with large two-way loudspeakers like LUA15, EXO15 and EXO18 and flown or stacked with EVO line-arrays in larger systems but BASSO21-A has been carefully tuned to deliver the optimal performance from 21’’ premium quality transducer thanks to the four symmetrical ports that allow for extremely linear excursion of the woofer with minimal distortion and high response in those regions where sound is rather felt than heard.
This extended frequency response reaches 29 Hz adding BASSO21-A “Infra” capabilities in large systems and applications those sub-sonic qualities are required.
BASSO21-A can also be served (on demand) with BASSO rigging structures, allowing for stacked and flown configurations.


  • Bass reflex design
  • 3.2 kW Class-D integrated power module
  • 24-bit 48kHz DSP
  • 4 selectable presets
  • Premium European High Efficiency custom IDEA Transducer
  • Neutrik® PowerCON and XLR connectors
  • Rugged and durable 18 mm birch plywood construction and finish
  • Durable Aquaforce paint, available in standard textured black or white,
  • Turn-key Factory Amplifier/DSP dedicated configurations
  • 36 mm pole cup and four integrated handles
  • Compatible rigging accessories (optional)
for stacked /flown configurations EVO Line-Array systems


  • High SPL A/V, portable professional sound reinforcement and touring
  • Main or distributed subwoofer system in Pubs, Lounges, Bars and clubs
  • Infra extension to other BASSO series subwoofers
  • Broadcast Studios and Screening rooms
Enclosure design Bass Reflex
Transducers 1 × 21″
Class D Amp Continuous Power 3.2 kW
DSP 24bit @ 48kHz AD/DA
4 selectable active LPF cuts
SPL (Continuous/Peak) 132/138 dB SPL
Frequency Range (-10 dB) 29 – 80/100/120/140 Hz
Frequency Range (-3 dB) 30 – 65/80/100/120 Hz
Dimensions (WxHxD) 600 × 600 × 950 mm
Weight 72.7 kg
Audio Signal Connectors
AC Connectors 2 x Neutrik PowerCON® (I/O)
Cabinet Construction 18 mm Plywood
Grille 2 mm perforated weatherised steel with protective foam
Finish Durable IDEA proprietary Aquaforce paint coating process
Handles 4 integrated handles
Feet/Skates 4 rubber feet
Installation Top 36 mm Pole-mount socket
Accessories Riggin Frame (RF-600)
Riggin System (RS-BASSO-L)
Wheels (WH-04)
35 mm Pole (K&M-21336)
Rain Coat for power module (RC-BASSO-M+RC-BASSOD-F)

* Specifications may be subject to change without notice.


Spare Parts

  • S21-41-8 | Woofer 21″
  • R-S21-41-8 | Membrane for Woofer 21″
  • AMP-DIGIMOD-3004PFC2 | Power Module
  • HSM-01 | Heat Sink medium
  • PM-DIGIMOD3004-PC2 (Power module + interface + DSP LITE + Heatsink)