Deus Audio Tesseract 18 – 18" Reference Infra-Bass Subwoofer Pair

18-inch driver. 137.6 dB peak output. 32mm one-way Xmax. Extension below 10 Hz.

The Deus Audio Tesseract 18 is a reference-grade 18-inch infra-bass subwoofer engineered specifically for high-end two-channel audio. Rather than prioritizing maximum output alone, Deus designed the Tesseract around extremely low distortion, transient accuracy, mechanical isolation, and seamless integration with reference loudspeakers. Deus Audio Machines

At its core are Deus's IsoCore™ motor, Monolith Matrix™ enclosure, carbon-fiber composite cone, TrueTemp™ voice-coil monitoring, and a fully isolated system architecture using dedicated amplification and bass management.

IsoCore™ Ultra-Linear 18" Driver

The patent-pending IsoCore™ motor topology is designed to precisely shape and stabilize the magnetic field throughout the driver's stroke, maintaining linear behavior as excursion increases.

The 18-inch driver provides an exceptional 32mm / 1.26 inches of one-way Xmax at 82% BL. Its dual-core carbon-fiber composite cone maintains pistonic behavior with a first cone-breakup mode at 409 Hz. Deus Audio Machines

Monolith Matrix™ Enclosure

The Tesseract's Monolith Matrix™ enclosure is a four-layer cast epoxy structure incorporating carbon fiber, Sorbothane®, constrained damping, and mass loading.

Deus further isolates the driver through a single-point mounting system, with Sorbothane isolation used between the driver, enclosure, and floor interface. The zero-fastener enclosure architecture is designed to minimize resonance, stored energy, and mechanical vibration reaching the room or returning to the driver. Deus Audio Machines

Infrasonic Extension Below 10 Hz

With its Linkwitz Transform applied, the Tesseract 18 reaches 23.7 Hz at -3 dB, 17 Hz at -6 dB, and 9.7 Hz at -10 dB.

Native response without DSP is 28.7 Hz–343 Hz at -3 dB. The sealed enclosure uses a 12 dB/octave low-frequency rolloff, allowing natural room gain to extend its response deeper in-room. Deus Audio Machines

Up to 137.6 dB Peak Output

Deus specifies maximum output of 137.6 dB peak and 134.6 dB continuous at 1 meter, 2π anechoic.

The Tesseract also achieves 96 dB sensitivity at 2.83V/1m, while its published preliminary CTA-2010 measurements demonstrate low distortion across the operating range. Deus Audio Machines

TrueTemp™ Direct Thermal Monitoring

TrueTemp™ measures voice-coil temperature directly rather than estimating it mathematically.

This provides real-time thermal data to the companion amplifier's protection architecture, allowing the system to manage thermal conditions under demanding operation while preserving performance. Deus Audio Machines

Engineered as a Complete Two-Channel Bass System

The Tesseract 18 is designed to operate as part of a complete Deus architecture with a dedicated Bass Manager and AMP L1 amplifier, each housed separately to isolate sensitive signal processing, amplification, heat, and vibration. Deus Audio Machines

The Bass Manager provides full-range signal pass-through, precision crossover integration, boundary compensation, and delay compensation, allowing the Tesseract to integrate with high-end main loudspeakers without compromising the primary signal path. Deus Audio Machines

Technical Specifications

Preliminary CTA-2010 Performance

Deus currently labels these CTA-2010 figures preliminary, so I would retain that wording in the Shopify listing rather than presenting them as finalized certification data. Deus Audio Machines

Multiple Tesseract 18 Systems

Deus recommends one, two, or more Tesseract 18 subwoofers per listening space, with distributed placement available to address room modes and create more uniform low-frequency response. The enclosure can also be configured to stack as many as three Tesseract 18s. Deus Audio Machines

That makes the platform particularly interesting for reference two-channel rooms where the objective isn't simply more bass, but consistent bass response across the listening environment.

Deus Tesseract 18 at The Grid HiFi

At 325 pounds per subwoofer, the Tesseract 18 deserves the same level of system engineering as the reference loudspeakers and electronics around it.

The Grid HiFi can design a complete Tesseract system around your main loudspeakers, room dimensions, listening position, amplification, crossover strategy, acoustics, isolation, and calibration, including multi-subwoofer configurations where appropriate.

Complimentary White Glove Delivery is included.

Building a reference two-channel system? Call The Grid HiFi at (713) 218-8120 to discuss the Deus Audio Tesseract 18 and complete system integration.