JTR Captivator 4000ST | Dual 18" 4000W Powered Subwoofer

Freight calculated by JTR after order entry

The JTR Captivator 4000ST is an extreme-output, ultra-low-frequency powered subwoofer built for reference home theaters and high-performance audio systems requiring enormous bass capability with genuine infrasonic extension. Combining dual high-excursion 18-inch drivers, a built-in 4000-watt RMS DSP-controlled Class D amplifier and a massive bass-reflex enclosure tuned to 10 Hz, the Captivator 4000ST is designed to reproduce the deepest movie effects and demanding musical bass with tremendous authority.

The ST configuration packages this performance into a wide, low-profile 28-inch-high enclosure, making it particularly useful for installations where the taller 4000TL cabinet is less practical.

Dual High-Excursion 18-Inch Drivers

At the heart of the Captivator 4000ST are two 18-inch drivers with 36 mm of Xmax, providing the displacement required to generate exceptionally high output at extremely low frequencies.

JTR's current drivers feature redesigned motor structures with more than a pound of aluminum within each driver's motor and less than 1 mH of inductance. JTR states that the design produces approximately 30% lower distortion than its previous reference drivers.

Both drivers are completely front-firing, providing greater installation flexibility within dedicated theaters and listening rooms.

4000-Watt RMS DSP Amplifier

The Captivator 4000ST incorporates a 4000-watt RMS Class D amplifier capable of operating at up to 95% efficiency.

Integrated DSP is optimized specifically for the subwoofer's drivers, enclosure and port system. JTR's current DSP implementation includes automatic input selection, advanced automatic turn-on and a reduced noise floor.

Connections include both RCA and balanced XLR inputs, along with a 12-volt trigger for integration with home theater processors and control systems.

Bass-Reflex Design Tuned to 10 Hz

The Captivator 4000ST is built to operate where conventional subwoofers begin to run out of usable output.

Its large bass-reflex enclosure is tuned to 10 Hz and uses a substantial slot port designed to minimize turbulence and compression at high output levels.

JTR rates the Captivator 4000ST at an extraordinary:

10.5 Hz – 125 Hz ±3 dB

This allows the 4000ST to reproduce not only traditional bass but also the infrasonic low-frequency information found in demanding modern movie soundtracks.

Wide, Low-Profile ST Configuration

One of the most important differences between the 4000ST and 4000TL is cabinet orientation.

The Captivator 4000ST measures 28 inches high × 58 inches wide × 20.5 inches deep. This wide-format enclosure can be advantageous beneath projection screens, behind acoustically transparent screens, along front theater walls or in other installations where minimizing cabinet height is important.

Despite the different cabinet orientation, the 4000ST retains the tremendous output capability and ultra-low-frequency extension expected from JTR's dual-18-inch Captivator platform.

LF Adjust for Room Integration

The Captivator 4000ST includes JTR's LF Adjust, providing additional flexibility when integrating the subwoofer into different acoustic environments.

This allows the low-frequency response to be adapted for applications ranging from smaller enclosed rooms, where substantial room gain may be present, to environments with less low-frequency reinforcement.

Combined with professional DSP, placement and calibration, this makes the 4000ST an exceptionally capable foundation for sophisticated single- or multi-subwoofer systems.

Baltic Birch Construction

Generating extreme low-frequency output places enormous mechanical demands on a subwoofer enclosure.

JTR constructs the Captivator 4000ST from 18 mm, 13-ply void-free Baltic Birch plywood and heavily braces the cabinet to maintain structural rigidity under the forces generated by its dual high-excursion drivers.

The enclosure is finished in Matte Black Paint and includes a magnetically attached grille for a clean appearance in dedicated theater installations.

Built for Reference Home Cinema

The Captivator 4000ST is designed for serious systems where deep extension and high output are fundamental requirements rather than optional upgrades.

Its combination of dual 18-inch drivers, 36 mm Xmax, 4000 watts RMS and 10 Hz enclosure tuning makes it particularly suited to large dedicated theaters, reference media rooms and multi-subwoofer systems designed to produce powerful, controlled bass across multiple seating positions.

Technical Specifications

Shipping / Freight Notice

JTR Speakers products require additional freight charges. Freight is not included at checkout. After your order is received, JTR will calculate the applicable shipping/freight cost based on the product and delivery destination. An additional freight charge will be invoiced after order entry.

JTR Captivator 4000ST at The Grid HiFi

The JTR Captivator 4000ST brings true ultra-low-frequency performance to reference home cinema in a wide, low-profile cabinet that can be especially useful for screen-wall and dedicated theater installations. With dual 18-inch drivers, 4000 watts RMS of amplification and extension to 10.5 Hz ±3 dB, it is engineered for systems where both tremendous output and genuine infrasonic performance are required.

At The Grid HiFi in Houston, Texas, we can help integrate JTR subwoofers into complete high-performance cinema systems, including subwoofer placement, multi-subwoofer layouts, surround processing, room acoustics and professional system calibration.