SU221

Structural Engineer Not Included.

Touring Subwoofers SUBIUM

Where to buy

Description

Perfect tonal reproduction—and everything else in the vicinity—the CELTO SU221 delivers a monumental 3600W RMS (14400W peak) with controlled extension down to 28 Hz and impressive 102 dB/1W/1m efficiency. This flagship vented dual 21" subwoofer sets the standard for multi-purpose touring and large-scale permanent installations requiring ultimate low-end authority. Designed for stadiums, festivals, arenas, concert halls, and premium nightclubs where flawless, powerful bass is the foundation of the experience. Twin custom 21" CELTO drivers with ±15 mm linear Xmax and patented DCS cooling system provide extraordinary excursion and minimal compression under extreme demand. Heavily braced Baltic birch plywood cabinet with tongue-and-groove assembly and rubberized PolyUrea finish guarantees dynamic, resonance-free performance. Capable of 137 dB RMS / 143 dB peak SPL with precise, musical character throughout its range. Dual M20 sockets and genuine Neutrik Speakon connectors support flexible array configurations and rapid deployment. Optional padded bag, pole bar, and castor kit ensure touring-ready protection and mobility. The SU221 affirms its position as the pinnacle of the SUBIUM series—delivering bass that doesn't just support the music, it defines it.

Key Features

Multi-purpose touring vented subwoofer
Down to 28Hz and still 102dB/1W/1m Efficiency
Real 3600W RMS power capacity
Premium 2 x 21” LF drivers with massive ±15mm linear Xmax
Patented DCS cooling system for low power compression
Heavy braced cabinet for vibration free dynamic response
Touring grade Rubberized black PolyUrea finish

Applications

Touring Engineered to endure

Technical specifications

Speaker type	Vented Subwoofer
Power Handling (AES standard)	3600 W RMS / 14400 W peak
Nominal impedance	4Ω
Average sensitivity	102 dB / 1 W / 1 m
Maximum SPL (calculated)	137 dB RMS / 143 dB Peak
Frequency response (-6 dB no preset)	28~1500 Hz
Nominal directivity (-6 dB)	Omni in usable range
Cabinet	Marine grade Baltic Birch Plywood Heavily braced with Tongue & Groove
Cabinet finish	Touring Grade Rubberized PolyUrea Black coating Acoustic PU foam behind Front grill
Flying hardware	No
Mounting hardware	2pcs M20 thread socket
LF	2x 21" CELTO 21SW2000-8
Woofer Chassis	Die Cast Aluminium
Woofer Voice coil	4.5" / 115 mm long throw
Crossover	No, active mode only
Connectivity	Genuine NEUTRIK 2pcs Speakon NL4 MP
Speaker size (HxWxD)	588 x 1226 x 805 mm
Speaker Weight	104 kg
Shipping information	117 kg 710 x 1380 x 915
Accessories	CSW221-SBAG (padded cover bag) CPC-70 (pole bar with crank) SUBWHKIT100C (castor wheel kit)

Product files

Name	Category	Type	Size
CELTO_SU221_A0_20250712_WEB_CAD CELTO_SU221_A0_20250712_WEB_CAD	CELTO_SU221_A0_20250712_WEB_CAD	PDF	115.5 KiB	Download
CELTO_SU221_A0_20250712_WEB_CAD CELTO_SU221_A0_20250712_WEB_CAD	CELTO_SU221_A0_20250712_WEB_CAD	DWG	999.1 KiB	Download