Features:

800W RMS / 1600W Program Power: Delivers tremendous sub-bass power output and thermal resilience for large-scale sound reinforcement setups.
8-Ohm Nominal Impedance: Standard professional system impedance for efficient amplifier matching and multi-cabinet parallel wiring.
Large 4-Inch High-Temperature Voice Coil: Wound on a heavy-duty former to manage extreme electrical loads and minimize thermal compression.
Reinforced Long-Fiber Paper Cone: Provides optimal stiffness-to-weight ratio for deep, articulate low-end projection without cone deformation.
Die-Cast Aluminum Frame: Rigid, non-resonant chassis prevents basket flexing and keeps the heavy magnet structure precisely aligned.
Double-Spider Suspension System: Maintains mechanical linearity and cone centering during high linear excursion (Xmax) playback.
Vented Cooling System: Integrated air ventilation channels dissipate heat away from the voice coil gap during long-duration performance.

Specifications:

JBL 18SW3P Subwoofer Specifications

High-power subwoofer for professional use, specifically designed for frequency response from 37 to 150 Hz in vented boxes with volumes between 150 and 250 liters, supporting 800 W RMS (AES Standard or 1,600 W continuous program power) or horn-loaded enclosures.

The magnetic assembly optimized using the Finite Element Method (FEA) results in high efficiency and low weight. The use of a T-yoke with an undercut bottom washer ensures a maximum excursion (Xlim) compatible with its power capacity. This component also features an extended pole piece, which improves magnetic field distribution and heat dissipation, reducing distortion and power compression. Special attention was given to the driver's behavior under mechanical overload conditions, enabling it to withstand severe working conditions without failure.

The 4" (100 mm) 4-layer round aluminum wire voice coil is wound on a fiberglass former with twice the thickness of standard formers, giving the moving assembly high structural rigidity. The non-pressed long-fiber paper cone possesses sufficient mass and rigidity to withstand massive acceleration forces, accurately centered by two spiders made of polyester-cotton fabric.

The cast aluminum frame provides structural rigidity and functions as a heat sink without introducing losses to the magnetic flux. A triple ventilation system (center hole, six holes in the bottom washer, and six windows in the frame) guarantees necessary cooling to sustain high power levels.

Technical Specifications

Nominal Diameter	457 mm (18 in)
Nominal Impedance	8 Ω
Minimum Impedance @ 90 Hz	7.2 Ω
PEAK Power	3,200 W
Continuous Program Power	1,600 W
RMS Power	800 W
AES Power	800 W
Sensitivity (1W @ 1m) average 50 to 150 Hz	96 dB SPL
Power Compression @ 0 dB (Nom. Power)	3.6 dB
Power Compression @ -3 dB (Nom. Power / 2)	2.9 dB
Power Compression @ -10 dB (Nom. Power / 10)	1.3 dB
Frequency Response @ -10 dB	37 to 2,000 Hz

Thiele-Small Parameters

Fs (Resonance Frequency)	37 Hz
Vas (Equivalent Volume)	215 L
Qts (Total Q Factor)	0.41
Qes (Electrical Q Factor)	0.43
Qms (Mechanical Q Factor)	11.51
η0 (Reference Efficiency in Half-Space)	2.42%
Sd (Effective Cone Area)	0.1194 m²
Vd (Displaced Volume)	806 cm³
Xmax (Max Excursion @ 10% Distortion)	6.75 mm
Xlim (Max Excursion before Damage)	21.0 mm

Additional Specifications & Non-Linear Parameters

BL	23.4 Tm
Flux Density in Gap	0.86 T
Voice Coil Diameter	100 mm
Voice Coil Wire Length	48.0 m
Re (DC Resistance)	5.7 Ω
Mms (Moving Mass)	175.8 g
Le @ Fs	9.636 mH
Le @ 1 kHz	4.509 mH
Magnet Material	Barium Ferrite
Magnet Weight	3,440 g
Frame Material	Cast Aluminum
Cone Material	Non-pressed long-fiber cellulose
Net Weight	11,300 g
Gross Weight (with packaging)	12,950 g
Packaging Dimensions (L x W x H)	48 x 48 x 25 cm