DEI Under Carpet Sound Deadening Layer - 48in x 54in

Silence Road Noise and Heat With DEI Boom Mat Under Carpet Sound Deadening Layer

The DEI 50101 Boom Mat Under Carpet Sound Deadening Layer is an 18-square-foot (54" x 48") two-material acoustic mat engineered to cut road noise, vibration, and heat transfer in any vehicle. Placed under carpet, on firewalls, or on any interior panel surface, the 50101 delivers a 5.6 dB(A) reduction in cabin noise, which DEI rates as a 25% improvement over leading competing products. The dual-layer construction pairs a flexible mass loaded barrier on top with an industrial-grade acoustical marine foam underneath, addressing both airborne sound and structure-borne vibration simultaneously. Whether you are building a custom interior, restoring a classic, or simply trying to make your daily driver quieter, the 50101 is the large-format under carpet material that gives you the most coverage per roll. DEI recommends layering the 50101 over Boom Mat Damping Material for the quietest possible result.

Key Features

• DEI 50101 Boom Mat Under Carpet Sound Deadening Layer, 54" x 48" (18 sq. ft.)
• 5.6 dB(A) noise reduction, rated 25% better than leading competitors
• Dual-layer construction: flexible mass loaded barrier (1 lb/sq. ft.) over industrial acoustical marine foam
• Reduces road noise, engine noise, vibration, squeaks, and rattles
• Provides thermal insulation to keep interiors cooler in summer and warmer in winter
• 3/8" thick for significant noise and heat attenuation without excessive bulk
• Installs under carpet, on firewalls, floors, and interior panels
• Can be mechanically fastened or adhered with Boom Mat Hi-Temp Spray Adhesive
• Universal fit, works in any car, truck, SUV, or custom vehicle build
• Designed to be used alone or over Boom Mat Damping Material for maximum NVH elimination

Specifications

What's Included

• 1 x DEI 50101 Boom Mat Under Carpet Sound Deadening Layer (54" x 48", 18 sq. ft.)

Frequently Asked Questions

The 50100 is the smaller 24" x 54" (9 sq. ft.) version of the Boom Mat Under Carpet layer. The 50101 is the larger 48" x 54" (18 sq. ft.) version, offering twice the coverage. Both use the same dual-layer mass loaded barrier over marine foam construction. Choose the 50101 for floor and firewall coverage in a full-size truck, SUV, or van, or any build where you want to minimize cuts and seams.

The 50101 works as a standalone sound deadener and thermal insulator and will provide meaningful noise reduction on its own. However, DEI recommends using it as a second layer over Boom Mat Damping Material for the quietest possible result. Boom Mat Damping Material addresses panel resonance and vibration at the metal surface, while the Under Carpet layer handles airborne noise and provides a thermal break. Together they create a comprehensive acoustic and thermal barrier.

DEI rates the 50101 at a 5.6 dB(A) reduction in cabin noise, which they state is a 25% improvement over the leading competitor's product. A 5.6 dB reduction is perceptually significant, as every 3 dB represents a halving of acoustic energy. For a vehicle with significant road, tire, or exhaust noise intrusion, this is a noticeable improvement in interior sound quality.

Yes. The Boom Mat Under Carpet material is designed for automotive interior applications including firewalls, floors, and door panels where moderate underhood heat exposure can occur. The marine-grade foam bottom layer provides thermal insulation in addition to acoustic damping. For extreme underhood heat applications, DEI recommends adding their Boom Mat Damping Material first and topping with the Under Carpet layer for a dual thermal and acoustic barrier.

The 50101 can be installed by mechanical fastening or with DEI's Boom Mat Hi-Temp Spray Adhesive (part 10490). For flat horizontal surfaces like floors, mechanical fastening or weight from the carpet itself is typically sufficient. For vertical surfaces like firewalls and door skins, using the Hi-Temp Spray Adhesive ensures the material stays in position during installation and for the life of the vehicle.

Yes. The 50101 cuts easily with sharp scissors or a utility knife. The large 18-square-foot format gives you plenty of material to work with when trimming around floor cutouts, seat bolt locations, and irregular panel shapes. Score the mass loaded barrier side and flex to cut cleanly, or use heavy-duty scissors for a single-pass cut.

Yes, especially when installed over the floor and firewall. Trucks and body-on-frame SUVs typically have minimal factory sound deadening compared to unibody cars, and the large-format 50101 is an efficient way to cover the cab floor, transmission tunnel, and firewall in a single application. Combined with Boom Mat Damping Material on the metal panels, the 50101 can produce a dramatic improvement in interior sound quality for pickups and full-size SUVs.

DEI (Design Engineering Inc.) stands behind the quality of their Boom Mat product line. Contact DEI directly at their support line or through their website for specific warranty terms and any installation questions specific to your vehicle or application.

Installation Instructions

1. Remove seats, carpet, and any trim panels as needed to expose the bare floor and firewall areas you intend to treat.
2. Clean the floor surface thoroughly and remove any existing OEM sound deadening, rust, or contamination. Allow to dry completely.
3. Measure and mark cut lines on the 50101 mat using the surface area dimensions. Use a sharp utility knife or heavy-duty scissors to trim to shape.
4. For flat floor sections, lay the 50101 foam-side down and press firmly into place. Use mechanical fasteners if needed to secure edges.
5. For vertical surfaces such as firewalls or door skins, apply Boom Mat Hi-Temp Spray Adhesive to both the panel surface and the mat back, allow to tack, then press firmly into place.
6. Overlap seams by 1" where multiple pieces meet to eliminate acoustic gaps.
7. Reinstall carpet over the completed mat layer. The 3/8" thickness is designed to allow carpet to reinstall cleanly without requiring seat or trim adjustments on most vehicles.
8. Reinstall all trim, seats, and hardware. Test for any squeaks or rattles before returning the vehicle to service.