Selection of Soundproofing Materials

1. Difference Between Soundproofing and Sound Absorption

  1. Soundproofing Materials

    • Function: Block sound transmission through dense structures (e.g., walls, doors, windows).

    • Key Metric: Mass law (higher density and weight improve soundproofing).

    • Examples: Soundproofing mats, lead sheets, concrete, gypsum boards.

  2. Sound-Absorbing Materials

    • Function: Reduce reflections and reverberation by absorbing sound energy via porous structures (e.g., studio walls).

    • Key Metric: Noise Reduction Coefficient (NRC; higher values indicate better absorption).

    • Examples: Polyester fiber panels, rockwool, fiberglass, perforated wood panels.

Note: Sound-absorbing materials alone cannot fully block noise; they must be combined with soundproofing materials.


2. Common Soundproofing Materials and Applications

1. Soundproofing Mat (Mass Loaded Vinyl, MLV)

  • Features: High density, flexibility; often paired with gypsum/wood boards.

  • Applications: Wall/ceiling layers, pipe wrapping, floor vibration damping.

  • Advantages: Flexible installation, ideal for small spaces.

2. Soundproofing Wool (Fiberglass/Rockwool)

  • Features: Porous structure for absorption + soundproofing; requires sealing layers (e.g., gypsum boards).

  • Applications: Ceiling/floor filling, HVAC duct insulation.

  • Caution: Rockwool fibers may irritate; ensure proper sealing.

3. Polyester Fiber Acoustic Panels

  • Features: Eco-friendly, customizable colors/shapes; primarily for absorption.

  • Applications: Home theaters, conference rooms, music studios.

4. Damped Soundproofing Boards

  • Features: Multi-layer composite (dense board + MLV + gypsum); excellent noise blocking.

  • Applications: Professional studios, KTVs, equipment rooms.

5. Soundproof Windows/Doors

  • Windows: Thermal-break aluminum frames + double-pane glass (≥12mm air gap recommended).

  • Doors: Soundproofing wool core + silicone seals.

  • Applications: Buildings near roads/highways.

6. Vibration Damping Materials

  • Examples: Rubber pads, spring isolators.

  • Applications: Floor impact noise reduction, machinery vibration control.

7. Low-Frequency Noise Solutions

  • Issue: Low-frequency noise (e.g., elevators, AC units) penetrates easily.

  • Solutions: Lead sheets + MLV + air gaps, or specialized acoustic dampers.


3. Key Factors for Material Selection

  1. Noise Type

    • High-frequency (voices, instruments): Absorption + sealing.

    • Low-frequency (vibrations, machinery): Dense materials + damping.

  2. Budget

    • Budget-friendly: Fiberglass + gypsum boards (moderate effect).

    • Professional: Damped boards + damping structures (high performance).

  3. Eco-Friendliness

    • Prioritize polyester fiber, formaldehyde-free gypsum; avoid exposed fiberglass.

  4. Space Constraints

    • Small spaces (e.g., apartments): Thin MLV (3–5mm) + decorative layers.

    • Large spaces (e.g., factories): Multi-layer composite walls.


4. Recommended Solutions for Common Scenarios

1. Home Bedroom

  • Walls: Gypsum board + MLV (or soundproofing wool).

  • Windows: Double-pane glass + PVC frames.

  • Doors: Solid wood + weatherstripping.

  • Floor: Carpet + rubber underlay.

2. Recording Studio/Home Theater

  • Walls: Polyester panels + bass traps (triangular corner units).

  • Doors/Windows: Professional seals + laminated glass.

  • Ceiling: Resilient channels + soundproofing wool.

3. Industrial Equipment

  • Enclosures: Lead-lined casing + internal absorption.

  • Pipes: MLV wraps + metal cladding.

  • Vibration Control: Spring isolators under machinery.


5. Installation Tips

  1. Sealing: Use acoustic caulk for gaps to prevent "sound leaks."

  2. Layered Design: Combine dense layers, absorptive layers, and air gaps.

  3. Fire Safety: Use fire-rated materials (e.g., rockwool, magnesium boards) in public areas.


6. Common Myths

  • Myth 1: Egg crate foam panels block noise → Only absorb sound, not block it.

  • Myth 2: Thick curtains stop low-frequency noise → False; pair with soundproof windows.

  • Myth 3: Soundproofing one wall is enough → Noise travels through floors/ceilings.


Conclusion: No universal solution exists. Tailor materials to noise sources and budgets. For critical projects, consult acoustic professionals.