Sale unit: one custom underseat enclosure.

Pickup only — this enclosure is not available for shipping. The completed enclosure is configured for local pickup through SMS Car Audio in Marrero, Louisiana.

Build the Enclosure Around Your Truck and Exact Subwoofers

This SMS Precision enclosure is built to order for compatible 2007–2026 Chevrolet Silverado and GMC Sierra Crew Cab trucks. Start with the truck year, choose the subwoofer layout, tell us the exact subwoofer or let SMS verify it, choose the finish, then decide whether you want any optional fabrication upgrades.

The builder keeps the order locked until the required fitment and clearance acknowledgements are complete. SMS reviews the final configuration again before fabrication begins.

Before You Order

• Cab: Crew Cab applications covered by the builder.
• Truck year: Choose the exact year first so the correct enclosure generation and seat-clearance rules load.
• Seat lift: 2007–2018 applications require a rear-seat lift. Seat-lift hardware and cost are separate unless specifically stated. 2019–2026 configurations in this builder do not require the seat lift.
• Subwoofer layouts: 2 × 6.5, 4 × 6.5, 6 × 6.5, 2 × 8, 4 × 8, or 2 × 10-inch.
• Exact driver: Choose the exact subwoofer when you know it. If not, choose SMS will verify it with me.
• 10-inch layouts: Require final subwoofer depth and clearance review before fabrication. Drivers over 6.5 inches published mounting depth receive an additional deep-driver review.
• Not included: Subwoofers, amplifier, wiring, installation, and seat-lift hardware where required unless specifically stated.

Base Enclosure Pricing

The truck generation and subwoofer layout control the enclosure geometry. Base enclosure price is determined by the selected finish, not by subwoofer count.

• Bare Wood — $500
• Carpeted — $650
• Bed Lined — $750
• Vinyl Face — $850

Optional fabrication upgrades are added separately in the builder and shown in the final review before the order is submitted.

Choose the Correct Truck Year First

2007–2013 Silverado / Sierra Crew Cab

Select the exact truck year in this range. These applications require a rear-seat lift, and the builder requires acknowledgement of that requirement before Add to Cart can unlock.

2014–2018 Silverado / Sierra Crew Cab

These trucks use the later enclosure fitment group but still require a rear-seat lift. The lift requirement and separate hardware/cost acknowledgement remain part of the order review.

2019–2026 Silverado / Sierra Crew Cab

For the configurations covered by this builder, the rear-seat lift is not required. The builder therefore does not require the seat-lift acknowledgement for these years.

Choose the Subwoofer Layout Around the System

The layout controls the baffle pattern and exact driver fitment. It is not a simple “more subs is better” ladder. The amplifier, final impedance, electrical support, driver requirements and usable underseat space still have to agree with the system plan.

• 2 × 6.5-Inch: Pair of compatible 6.5-inch subwoofers.
• 4 × 6.5-Inch: Four compatible 6.5-inch subwoofers.
• 6 × 6.5-Inch: Six compatible 6.5-inch subwoofers.
• 2 × 8-Inch: Pair of compatible 8-inch subwoofers.
• 4 × 8-Inch: Four compatible 8-inch subwoofers.
• 2 × 10-Inch: Pair of compatible 10-inch subwoofers with mandatory final clearance review.

Built Around the Exact Subwoofer

Nominal size is not enough to establish fitment. Two subwoofers sold as the same diameter can use different cutouts, frame diameters, baskets, motors, terminals and mounting depths.

If the exact model is available in the builder, select it. If the model is not listed, its dimensions still need verification, or you simply are not sure which version you have, choose SMS will verify it with me. You do not need to stop checkout and guess at dimensions. SMS confirms the exact driver and final clearance before fabrication.

10-Inch & Deep-Driver Clearance Review

Every 10-inch layout requires a final depth and clearance review. SMS confirms mounting depth, basket and motor clearance, seat structure and usable enclosure space before the box is cut.

If the selected subwoofer has a published mounting depth over 6.5 inches, the builder also identifies it as a deep-driver review. A nominal 10-inch diameter does not guarantee underseat clearance.

Choose the Finish

Bare Wood: fabricated enclosure without a cosmetic finish.

Carpeted: conventional finished enclosure surface.

Bed Lined: tougher coated finish for a durable utility-style surface.

Vinyl Face: upgraded visible face treatment when presentation matters.

Optional Fabrication Upgrades

After the required enclosure choices are complete, the builder can show optional paid upgrades such as LED lighting, engraved LED acrylic, 45-degree corners, terminal upgrades, pre-wiring, front-panel engraving and an aero-port upgrade where the enclosure design allows it. Nothing in the upgrade step is required.

Selected upgrades are charged separately and included in the final review total.

What Happens After Checkout

Your order does not go straight into fabrication. SMS Car Audio reviews the selected truck year, enclosure layout, exact subwoofer or SMS-verification choice, finish, required seat-lift acknowledgement where applicable, clearance review and paid upgrades.

If you chose SMS will verify it with me, we confirm the exact subwoofer dimensions and manufacturer requirements with you. For 10-inch layouts or deeper drivers, we also confirm basket, motor, seat-structure and usable-space clearance before cutting the enclosure.

Once the truck fitment, driver clearance, layout, finish and selected upgrades are confirmed, the enclosure moves into fabrication for local pickup in Marrero.

Exact Product Details