Soundproof panels are typically made from a core of dense, porous material like fiberglass, mineral wool, polyester felt, or open-cell foam, wrapped in acoustically transparent fabric and sometimes supported by a wood or metal frame. The specific materials vary depending on whether the panel is designed to absorb sound (reducing echo and reverberation) or block sound (preventing noise from passing through a wall or ceiling).
Fiberglass and Mineral Wool Cores
Fiberglass and mineral wool are the most widely used core materials in professional acoustic panels. Both are fibrous, porous materials that trap sound energy as it passes through the tiny air pockets between fibers. That friction converts sound waves into a small amount of heat, effectively absorbing noise rather than letting it bounce around a room.
Fiberglass panels are lightweight, widely available, and perform well across mid and high frequencies. Mineral wool (sometimes sold under brand names like Rockwool) is denser and heavier, which gives it an edge at absorbing lower frequencies. Both materials can achieve very high Noise Reduction Coefficient (NRC) ratings, a scale from 0 to 1 where 1 means the material absorbs virtually all sound hitting it. Panels made from either material in 2-inch thickness commonly score between 0.8 and 1.0 NRC, making them standard choices for recording studios, home theaters, offices, and auditoriums.
Open-Cell Polyurethane Foam
The egg-crate or wedge-shaped foam tiles you see in studios and podcasting setups are made from open-cell polyurethane foam. During manufacturing, a blowing agent (usually water) creates bubbles inside the polyurethane as it cures, producing an interconnected network of tiny open cells. That open-cell structure is critical: it lets air move freely through the foam, which is what allows it to absorb sound. Closed-cell foam, by contrast, traps air in sealed pockets and reflects sound rather than absorbing it.
Acoustic foam is inexpensive, easy to cut, and simple to mount with adhesive. It works best on mid-to-high frequency sounds like speech and music reflections. It’s less effective at low-frequency rumble, which is why bass traps (thicker, denser foam or fiberglass panels placed in room corners) are used alongside standard foam tiles. One drawback: basic polyurethane foam can be flammable, so panels intended for commercial spaces are treated with fire retardants or replaced with inherently fire-resistant materials like fiberglass.
Recycled PET Felt
One of the fastest-growing materials in the acoustic panel market is PET felt, made primarily from recycled plastic bottles. Used bottles are collected, compressed, shredded, and melted into plastic flakes. Those flakes are mixed with a small percentage of virgin plastic fibers and pressed into sheets that look and feel like traditional felt. The resulting material is porous enough to absorb sound effectively while being rigid enough to hold its shape without a frame.
PET felt panels are popular in modern offices and restaurants partly because of aesthetics. They can be dyed in a wide range of colors and cut into decorative shapes, doubling as design elements. They’re also lightweight, contain no formaldehyde or glass fibers (making them safer to handle than fiberglass), and carry environmental appeal since each panel diverts plastic from landfills. Their sound absorption isn’t quite as high as dense fiberglass at the same thickness, but for controlling echo in everyday spaces, they perform well.
Mass Loaded Vinyl for Sound Blocking
Most acoustic panels absorb sound to improve the acoustics inside a room. If your goal is to block sound from traveling between rooms, the key material is mass loaded vinyl (MLV). This is a thin, flexible sheet, typically 1/8 to 1/4 inch thick, made from vinyl infused with calcium carbonate to make it extremely dense. It weighs between 0.6 and 2 pounds per square foot despite being so thin.
MLV works on a simple principle: the denser and heavier a barrier is, the harder it is for sound waves to push through it. Because the material is limp rather than rigid, it also resists vibration, which makes it particularly effective at blocking low-frequency sounds like bass, traffic noise, and mechanical hum. Installers typically hang it directly against wall studs or ceiling joists, where its flexibility allows it to drape loosely. This “limp mass” behavior helps it absorb energy from larger sound waves that would vibrate right through a stiff panel.
Newer versions use polyolefin elastomer (POE) instead of traditional PVC. POE-based MLV doesn’t contain plasticizers, doesn’t emit volatile organic compounds as it ages, and is considered non-toxic even if burned.
The Fabric Covering
The fabric wrapped around an acoustic panel isn’t just decorative. It needs to be acoustically transparent, meaning sound waves pass through it without being reflected or distorted before reaching the absorbent core. If the fabric blocks sound, the panel’s performance drops significantly.
Acoustically transparent fabrics are tested under standardized methods that measure how much sound passes through the fabric into a foam core versus how much the fabric itself reflects or absorbs. Common options include polypropylene weaves, recycled polyester, wool felt, and wool-flax blends. When shopping for panels or building your own, a quick test is to hold the fabric up to your mouth and blow through it. If air passes through easily, sound will too. Tightly woven materials like canvas or vinyl will reflect sound and defeat the purpose of the panel.
Frames and Structural Support
Many acoustic panels use an internal wooden frame, typically made from pine, poplar, or similar lightweight hardwoods, to keep the core material rigid and provide mounting points. The core insulation sits inside this frame, the acoustically transparent fabric wraps around the outside, and the whole assembly hangs on a wall or suspends from a ceiling. Some higher-end commercial panels use extruded aluminum frames for durability and a sleeker profile.
Frameless panels also exist, especially those made from PET felt or rigid fiberglass boards that are stiff enough to hold their shape on their own. These are typically glued or clipped directly to a surface.
Fire Safety Ratings
Any acoustic panel installed in a commercial building, school, or public venue needs to meet fire safety standards. In the United States, panels are tested for surface burning characteristics and classified into three tiers. Class A panels have the lowest flame spread (rated 0 to 25) and are required in most commercial applications, including offices, restaurants, theaters, and hospitals. Class B (flame spread of 26 to 75) and Class C (76 to 200) are acceptable in some residential or low-occupancy settings but are less common in professional installations.
Fiberglass and mineral wool cores are naturally fire-resistant and easily achieve Class A ratings. Polyurethane foam, PET felt, and fabric coverings may need fire-retardant treatments to qualify. If you’re buying panels for a home studio or personal space, fire ratings are still worth checking, especially if you plan to cover large wall areas with combustible material.
Choosing Materials by Goal
- Reducing echo and reverberation: Fiberglass, mineral wool, PET felt, or acoustic foam panels absorb sound within a room. Thicker panels (2 inches or more) handle a wider range of frequencies.
- Blocking sound between rooms: Mass loaded vinyl adds the dense, heavy barrier needed to stop noise transmission. It’s often combined with absorbent materials for a dual effect.
- Budget projects: Open-cell foam tiles are the least expensive option and work well for speech-frequency absorption in home offices or podcast setups.
- Aesthetic spaces: PET felt panels offer the best combination of sound control and visual design flexibility, available in colors and custom shapes without needing fabric wrapping.
- Maximum performance: Dense mineral wool cores wrapped in Class A fire-rated fabric, mounted inside hardwood frames, represent the professional standard for studios and performance venues.