As I mentioned in the previous post, even though Japanese roads are generally smooth and quiet, road noise can still be noticeable, especially in smaller cars like kei cars or compacts.
If you want a quieter ride, adding some noise reduction materials in the right spots can make a big difference.
1. Key Areas to Focus On
- Floor & Footwells – Main path for vibrations from tires and suspension.
- Trunk & Rear Bulkhead – Reduces noise reflection from the rear.
- Wheel Wells / Fender Liners – Tires generate a lot of sound here.
- Doors & Pillars – Thin panels transmit sound easily.
2. Materials for Noise Reduction
High-End (Best Performance)
- 制振材 / Butyl-based damping sheets – Great for reducing panel vibration.
- Popular in Japan: RealShield (レアルシルト), Amon kits (エーモン).
- Ideal for floors, doors, and trunk panels.
- 吸音材 / Thick acoustic foam or felt – Absorbs sound inside cavities.
- Often included in Amon kits or bought separately at car shops.
Mid-Range (Affordable DIY)
- Thin butyl sheets + felt – Easier to handle, decent noise reduction.
- Can be combined in key areas (floor + trunk + doors) for effective results.
- Available at Cainz (カインズ) or other Japanese home improvement stores.
Low-Cost (Budget-Friendly)
- Carpet scraps, dense felt, or bubble wrap layers – DIY-friendly and surprisingly effective in localized spots.
- Great for testing areas before investing in more expensive materials.
3. Tips for Effective Installation
- Focus first on areas where vibration enters the cabin.
- Cover as much metal surface as possible without interfering with moving parts.
- Combine damping + absorption for the best effect: damping stops vibration, absorption reduces the noise that enters the cabin.
- Start with small sections, test the effect, and expand gradually.
- For Japan-based readers: most of these materials are easy to buy at home improvement stores or specialized car shops, making it convenient even for DIY beginners.
In the next article, we’ll explore real-life results: which areas made the biggest difference and how it feels driving after applying these materials.