Modern soundproofing materials make a substantial difference to cabin noise levels in classic MGs without altering the look of the interior. Original-specification sound insulation in cars of this era was minimal, the MGA in particular used felt underlay only beneath the front floor and tunnel carpets, and the open-cockpit roadster was always a noisy car at speed. Adding modern soundproofing to the floor pan, transmission tunnel, inner wheel arches and bonnet underside reduces road, exhaust, drivetrain and engine noise reaching the cabin and produces a noticeably more refined driving experience. This category covers fitted kits, individual sheet materials, ancillary supplies and the application tools needed for a clean installation.
Tailored Soundproofing Kits
Pre-cut soundproofing kits are available tailored to specific MG models, including kits cut for the MGA interior, the MGB and MGB GT, and the Midget. These take the work out of cutting and fitting individual panels, with each section sized and shaped for a particular floor pan, tunnel and inner panel layout. Kits are typically constructed from jute or composite material with a crumb polyurethane base layer formulated to resist oil contamination, important on cars where small fluid leaks from the gearbox, axle or steering can reach the underside of the cabin floor over time. A separate bonnet soundproofing kit is offered for the MGB, die-cut to fit and supplied with self-adhesive backing for straightforward fitment.
Dynamat Xtreme, Sheet Materials
Dynamat Xtreme is a self-adhesive vibration-damping sheet material widely used across the classic car restoration field. It works by isolating panel vibration, the principal source of body-borne booming and resonance felt and heard inside a car at speed, and is applied directly to the inner faces of the floor pan, transmission tunnel, inner wheel arches and rear bulkhead. Dynamat Xtreme is supplied in pre-packaged kits sized to common application areas (door pack, speaker pack, wedge pack, bulk pack) and as individual sheets in three thicknesses suited to different applications: 1/8 inch, 1/4 inch and 1/2 inch for heavy-duty barrier work. The packs allow the right quantity to be ordered for the area being treated.
Dynapad, Dynaliner and Dynatape
Dynamat Xtreme is the first layer in a three-stage soundproofing approach. Dynapad is a heavy-duty barrier material used where the maximum reduction in airborne noise is required, typically on the floor pan and bulkhead, and is applied over the Dynamat Xtreme base layer. Dynaliner is a self-adhesive thermal-acoustic foam used to maximise both heat and noise insulation, fitted as the third layer over Dynapad or directly over Dynamat Xtreme depending on the level of treatment required. Dynatape is a foil tape used to seal the joints between sheets and around fixings, ensuring the layered system performs as a single continuous barrier rather than a patchwork of overlapping pieces.
The three materials work together rather than as alternatives.
Application Tools and Supplies
Dynamat Pro Roller is a hand-held roller used to bed the self-adhesive sheet material down firmly onto the panel surface, proper rolling is essential to achieving full adhesion and the maximum vibration-damping effect. Dynamat application gloves in a range of sizes protect hands during fitting, since the sheet edges can be sharp and the adhesive aggressive once trimmed. Both items are inexpensive but make a noticeable difference to the quality of the finished installation.
MGA Application Notes
For the MGA specifically, the most beneficial areas to treat are the floor pan (driver and passenger footwells), the transmission tunnel, the propeller shaft tunnel and the inner wheel arches. The roadster benefits noticeably from rear bulkhead treatment, while the coupé, which is inherently quieter than the roadster, sees the biggest gains from floor pan and inner wheel arch treatment to reduce road roar transmitted from the rear axle area. Soundproofing is most easily fitted with the interior carpet out and the floor pan exposed, so this work is best combined with a carpet renewal. The MGA Interior Soundproof Kit provides pre-cut sections sized to the MGA's layout, removing the need to cut individual sheets for each panel.
Installation Approach
Three rules apply to soundproofing installation. First, surfaces must be clean, dry and free of rust before adhesive-backed sheet material is applied, adhesion is permanent if done correctly, but compromised by contamination on the panel surface. Second, the material must be rolled firmly into the panel using the application roller, pressing by hand alone does not achieve the required bond. Third, all joints between sheets must be sealed with foil tape so that the assembly performs as a single continuous barrier.