Sealed Subwoofer Box

Compact design for deep, precise bass – perfect for audiophiles seeking accurate sound..

Looking for tight, accurate bass response? Our sealed subwoofer boxes are built for precision sound reproduction. Compact and efficient, these enclosures are designed to deliver clean low-end that works across all music styles. At Audio Intensity, every sealed box is CNC-cut, internally braced, and carpet-finished for lasting durability. Free shipping and a 2-year warranty come standard.

Sealed Subwoofer Box

Universal Sealed Subwoofer Box

Subwoofer Specific Sealed Boxes

Down Fire Sealed Subwoofer Boxes

Vehicle Specific Sealed Subwoofer Box

A close up of the internal bracing of the performance series box

Built for Precision. Engineered for Strength.

Proline-X sealed subwoofer boxes are proudly made in the USA, combining expert craftsmanship with next-level construction methods. Each enclosure uses precision CNC machining and advanced joinery techniques, including dado and V-bit construction. These methods lock panels together more securely than basic butt joints, creating a rigid, unified structure that resists flex and distortion, even under high-output conditions.

This high-precision build quality is especially important in sealed enclosures, where airtight integrity directly affects bass response and accuracy. Proline-X enclosures deliver clean, controlled, low-end performance that stays true to your music by minimizing panel movement and air leaks. Whether you're building a daily driver or a competition-grade system, the strength and consistency of a Proline-X box ensures dependable performance for years to come.

Close up of the new proline x terminal cu

Details That Matter. Performance You Can Hear.

Attention to detail at every level separates Proline-X from ordinary subwoofer boxes. Woofer-specific models include threaded inserts at the mounting points, allowing you to secure your subwoofer with machine screws instead of wood screws. This means no stripped holes, no air leaks, and easy serviceability down the line.

Every enclosure also features a custom-designed Proline-X terminal cup—built in-house for reliable, high-contact connectivity that won't loosen over time. Inside, each box is prewired with a 12-gauge oxygen-free copper (OFC) speaker wire chosen for its low resistance and clean signal transfer. These minor upgrades add real-world benefits, giving you a tighter connection, lower signal loss, and better sound quality. With Proline-X, you're not just buying a box but investing in a better audio experience.

All About Sealed Subwoofer Boxes

A sealed subwoofer box is the top choice for music lovers who want clarity, accuracy, and tight bass. Unlike ported designs, sealed enclosures focus on controlling cone movement, producing low distortion and a smooth response across frequencies.

Our Proline-X sealed boxes are engineered for efficiency in smaller airspace, making them ideal for cars, trucks, and SUVs where room is limited. They work exceptionally well with subs from Alpine, Image Dynamics, and Audiomobile. Each enclosure is precision-cut, dado-joined, and tested for airtight performance.

If you’re looking for more output, check out our ported enclosures. For space-saving installs, explore our shallow mount solutions. But for pure accuracy and musicality, sealed boxes remain the go-to choice.

Audiomobile Encore 12 inch Sealed Down Firing Subwoofer Enclosure|ProLine X|Audio Intensity

Sealed Subwoofer Box

Frequently Asked Questions

What is a sealed enclosure?

What sizes are available for sealed enclosures?

What materials are used in these enclosures?

What is the benefit of using a sealed enclosure?

Why is an airtight seal important in a sealed subwoofer box?