SU121TL G2

Single 21″. Shorts In Danger.

Touring Subwoofers SUBIUM

Where to buy

Description

Shorts-moving impact in a single, sophisticated package—the CELTO Acoustique SU121TL G2 commands 1600W RMS (6400W peak) with exceptional efficiency (103 dB/1W/1m) and extension to 33 Hz via advanced rear-loaded Transmission Line design. This premium single 21" subwoofer excels in touring and fixed applications requiring authoritative yet musical low-end without excessive cabinet volume. Perfect for medium to large venues, theatres, arenas, and high-fidelity systems demanding deep, controlled bass reinforcement. A custom 21" CELTO driver with massive ±15 mm linear Xmax and patented DCS cooling system ensures low power compression and outstanding thermal stability. Baltic birch plywood enclosure with comprehensive bracing, tongue-and-groove joints, and touring-grade rubberized PolyUrea finish delivers vibration-free reliability. Achieving 135 dB RMS / 141 dB peak SPL with pristine tonal accuracy across the spectrum. Dual M20 threaded sockets and genuine Neutrik Speakon connectors enable versatile stacking and integration. Complemented by optional padded cover, crank pole bar, and castor kit for effortless transport and setup. The SU121TL G2 proves that singular focus on engineering excellence can deliver bass that moves more than just air.

Key Features

Rear Loaded Transmission Line subwoofer
103dB/1W/1m Efficiency
Real 1800W RMS power capacity
Premium 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	Transmission line Subwoofer
Power Handling (AES standard)	1600 W RMS / 6400 W peak
Nominal impedance	8 ohms
Average sensitivity	103 dB / 1 W / 1 m
Maximum SPL (calculated)	135 dB RMS / 141 dB Peak
Frequency response (-6 dB no preset)	33~800 Hz
Nominal directivity (-6 dB)	Omni in usable range
Cabinet	Exterior grade Baltic Birch Plywood Heavily braced with Tongue & Groove
Cabinet finish	Touring Grade Rubberized PolyUrea Black coating Acoustic PU foam behind Front grill
Floor monitor use	N/A
Flying hardware	No
Mounting hardware	2pcs M20 thread socket
LF	21" CELTO ACOUSTIQUE 21SW1800-8
Woofer Chassis	Die Cast Aluminium
Woofer Voice coil diameter	4.5" / 115 mm long throw
Crossover	No, active mode only
Connectivity	Genuine NEUTRIK 2pcs Speakon NL4 mP
Speaker size (HxWxD)	850 x 590 x 770 mm
Speaker Weight	76 kg
Shipping information	87 kg 990 x 690 x 870
Accessories	SU121TL-SBAG (padded cover bag) CPC-70 (pole bar with crank) SUBWHKIT100C (castor wheel kit)

Product files

Name	Category	Type	Size
CELTO_CPC-70_A0_20250721_WEB_CAD CELTO_CPC-70_A0_20250721_WEB_CAD	CELTO_CPC-70_A0_20250721_WEB_CAD	PDF	33.1 KiB	Download
CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD	CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD	PDF	37.1 KiB	Download
CELTO_SU121TL_A0_20250712_WEB_CAD CELTO_SU121TL_A0_20250712_WEB_CAD	CELTO_SU121TL_A0_20250712_WEB_CAD	PDF	123.2 KiB	Download
CELTO_SU121TL_A0_20250712_WEB_CAD CELTO_SU121TL_A0_20250712_WEB_CAD	CELTO_SU121TL_A0_20250712_WEB_CAD	DWG	1.0 MiB	Download
CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD	CELTO_SUBWHKIT100C_A0_20250721_WEB_CAD	DWG	740.1 KiB	Download
CELTO_CPC-70_A0_20250721_WEB_CAD CELTO_CPC-70_A0_20250721_WEB_CAD	CELTO_CPC-70_A0_20250721_WEB_CAD	DWG	781.7 KiB	Download