Pair a single 12" subwoofer from our wide selection with Q-Logic's QLT-.8512sx truck enclosure. Made of 5/8" HDP (high density particleboard), with a 1-1/4" thick front panel of 5/8" MDF (medium density fiberboard) and 5/8" HDP, the box features reliable locking-joint construction, and is impeccably upholstered with durable gray carpet.

Since subwoofers' basket design and bolt patterns vary greatly by brand, Q-Logic's ingenious QxRing allows you to customize the box opening to accommodate a wider range of woofers. The box also comes with round, pressure-fit grilles, polyester fiber stuffing, gold-plated binding posts, and speaker leads (pre-wired to the terminal cup) with quick-slides for easy connection to your woofer.

This box is designed to fit behind the seat in your pickup. Some truck boxes may not fit in a standard cab with the seat pushed all the way back, so please measure the planned installation area to ensure fit. 1-year warranty.

Key Specifications:
  • holds one 12" subwoofer
  • .85 cubic foot internal volume
  • dimensions:
    • width: 25-1/8"
    • height: 15-3/16"
    • bottom depth: 7-11/16"
    • top depth: 5-1/4"

Why do I need an enclosure?

An enclosure is simply the box that houses your sub; sealed and ported enclosures are the most popular types. A sealed enclosure is usually smaller in size, sacrificing a little volume level to deliver more accurate bass. The ported enclosure features a vent which allows bass waves to escape from behind the mounted sub, augmenting the bass coming off the front of the sub. Ported boxes are louder, bigger, and a little less accurate. Every sub works best in the size and type of enclosure that's recommended by the manufacturer, so make sure you match your sub with the right box.

Hands-on research

What's in the box?

Download owner's manual

  • Single truck-style enclosure
  • 1 Plastic mesh grille
  • 1 Silver plastic grille frame (installed)
  • 1 Plastic Q-Ring (installed)
  • One 2' length of speaker wire (with 0.205" female quick slides on both ends)
  • Eight 1" self-tapping screws
  • 1 Polyfill batting
  • 1 "U-Channel" rubber strip
  • 2 Strips of self-adhesive foam
  • Instruction/Warranty sheet

Product Research


Materials: The box is constructed of 5/8" HDP (high-density particleboard) with a section of 5/8" MDF (medium-density fiberboard) adhered to the back of the front panel. The section of MDF provides the mounting surface for the woofer. Both materials resist flexing and have anti-resonant qualities. MDF is used as the mounting surface for the woofer because it accepts screws better than HDP. Having superior rigidity and anti-resonant qualities, HDP is used for the rest of the enclosure.

Design: For strength, Q-Logic uses a full dado groove on the front, back, top, and bottom panels. The side panels are glued, then locked into these grooves. The edges of the front, back, top and bottom are joined at an angle, so there's more surface area for the special glue that bonds them. The side panels of the box are recessed 0.5". The enclosure is covered with durable gray carpet.

Q-Ring Woofer Mounting System: The Q-Ring is a multi-diameter woofer mounting adapter. Mounting tabs on the Q-Ring center the woofer in the mounting hole. To accommodate various woofer cutout diameters, the mounting tabs on the Q-Ring can be trimmed.

Plastic Grille Frame: The speaker and grille mount in a recessed plastic grille frame in the front of the enclosure. The recess is 0.685" deep and has a diameter of 12.985". The maximum woofer frame diameter is 12.723", because a 0.131" gap is needed around the woofer frame to mount the mesh grille.

U-Channel Rubber Strip: The "U-Channel" rubber strip wraps around the edge of the grille and provides additional security when mounting the grille. 

Spring Posts: The spring posts, located on the rear of the enclosure, will accept bare wire, pin connectors, banana plugs, and dual banana plugs.

Brackets: Brackets (not included) are recommended for more secure mounting.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

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