Felt for Soundproofing: Benefits of PET Felt & Wool Felt

Why felt for soundproofing is so effective

Felt is one of the most effective materials for sound absorption. The mode of operation is based on the porous, fibrous structure: When sound waves hit felt, they penetrate the material and are converted into thermal energy there by friction between the fibers. The denser and thicker the felt, the more sound energy can be absorbed.

High-quality acoustic felts achieve a sound absorption coefficient (αw) of 0.9 – this means that up to 90 percent of the incident sound energy is absorbed. For comparison: Smooth walls reflect almost 100 percent of the sound, which leads to echo and unpleasant room acoustics. Covering just 15 to 20 percent of the wall surface with acoustic felt can noticeably improve room acoustics.

Another advantage of felt is its versatility. Unlike heavy insulation panels made of mineral wool or foam, felt can be easily cut, attached, and removed if necessary. This makes it particularly attractive for soundproofing in rental apartments, where structural changes are often not permitted.

PET felt: The sustainable standard for modern acoustic solutions

PET felt is made from recycled polyethylene terephthalate fibers – usually from old PET bottles. Through a special process, these fibers are cleaned, melted, and processed into a dense, stable non-woven fabric. The result is a material that is not only acoustically convincing but also ecologically sensible.

Technical properties of PET felt

The quality of PET felt can be assessed based on several parameters. The grammage (density) indicates how much material was processed per square meter. High-quality acoustic felts have a density of 1500 to 2000 g/m². The Felt Acoustic Panels 30x30 from Aeco Sound®, for example, achieve 2000 g/m² with a material thickness of 15 mm – significantly more than many competing products with only 1000-1200 g/m².

This high density ensures better sound absorption, especially in the middle and high-frequency range (500-4000 Hz), where human speech lies. At the same time, the material remains dimensionally stable and does not warp over time. The surface is often treated with a special seal that makes the material water-repellent and colorfast.

Benefits of PET felt at a glance

Particularly in sensitive areas such as children's rooms or bedrooms, freedom from pollutants is a decisive criterion. PET felt does not emit volatile organic compounds (VOCs) and is suitable for allergy sufferers. You can learn more about the application in various rooms in our guide on soundproofing in the apartment.

Wool felt: The natural alternative with tradition

Wool felt is made from natural sheep's wool fibers and has been known as an insulating material for centuries. Through fulling – mechanical processing under heat and moisture – the fibers interlock and form a dense, stable material. Wool felt has a long tradition in building acoustics and is still used in special applications today.

Acoustic properties of wool felt

Wool felt absorbs sound similarly well to PET felt, albeit with slightly different frequency behavior. The natural fibers are somewhat more flexible and can dampen particularly low frequencies well. For music rooms or home theaters, this can be advantageous if bass frequencies are problematic.

However, in practice, wool felt rarely achieves the same density as high-quality PET felt. Typical values are 800-1200 g/m², which reduces absorption performance compared to 2000 g/m² PET felt. In addition, wool felt is significantly more expensive to produce and more susceptible to moisture.

Comparison: PET felt vs. Wool felt

For most applications in living and working spaces, PET felt is the better choice. It combines high acoustic performance with practical properties and a sustainable approach. Wool felt remains an option for special requirements or when a completely natural solution is desired.

Non-woven fabric for soundproofing: Delimitation and areas of application

The term "non-woven" (Vlies) is often used synonymously with felt, but strictly speaking refers to a broader spectrum of textile sheet structures. While felt is created by fulling, non-wovens are produced by various processes – such as needling, gluing, or thermal fusion of fibers.

In soundproofing, various types of non-wovens are used. Acoustic non-wovens made of polyester fibers strongly resemble PET felt and are often marketed as "acoustic felt". Other non-wovens, such as those made of glass fibers or mineral wool, serve more as an insulation layer in wall and ceiling constructions. For subsequent measures without structural interventions, textile non-wovens made of PET are the most practical solution.

The self-adhesive soundproofing for the wall is typically based on highly compressed PET non-woven with a self-adhesive back. This combination enables tool-free installation without drilling or screwing – ideal for rental apartments or temporary solutions.

Installation and application of acoustic felt

Attaching felt for soundproofing is incredibly simple and requires no craftsmanship experience. Depending on the product and substrate, various installation methods are available.

Self-adhesive felt panels

The easiest variant is self-adhesive acoustic panels. The back is provided with a high-quality adhesive layer that adheres to almost all surfaces – wallpaper, plaster, wood, tiles, glass, or metal. Installation takes place in a few steps:

First, clean the wall surface thoroughly to remove dust and grease. Then peel off the protective film from the back of the panel and press it firmly into the desired position. For optimal adhesion, press the panel for about 30 seconds. The panels also adhere to cold walls and can be removed without residue if necessary.

Self-adhesive panels are particularly suitable for office spaces, home offices, and living areas. They can be arranged flexibly – whether as a geometric pattern, in rows, or as an accent wall behind the desk.

Installation with adhesive or fastening

Heavier acoustic solutions, such as the combination of felt and wood slats, require more stable fastening. The Wood Acoustic Panels from Aeco Sound® weigh about 5.2 kg per panel and are attached with mounting adhesive, screws, or nails.

Mounting adhesive offers the advantage that no visible fastening points are created. The adhesive is applied to the back of the panel, then it is pressed against the wall and fixed for a few minutes. This method works on all load-bearing substrates. Alternatively, screws or nails can be used, which enables residue-free removal – important for rental apartments.

Cutting and customization

One of the greatest advantages of acoustic felt is its easy workability. With a conventional utility knife or cutter, the panels can be cut precisely. This allows you to easily cover even difficult areas such as corners, cutouts for sockets, or sloping walls.

The rectangular panels from Aeco Sound® (30 x 30 cm) can be joined seamlessly and form a continuous surface without visible transitions. Unlike hexagonal designs, which often leave gaps, a homogeneous, visually calm surface is created here.

Areas of application: Where felt for soundproofing works best

Acoustic felt is versatile and improves room acoustics in almost every environment. The effect is particularly clear in rooms with many hard, reflective surfaces.

Living and working areas

In the living room, acoustic felt reduces disturbing echo and creates a pleasant conversation atmosphere. Particularly when placed behind the TV or music system, it prevents echo effects and improves sound quality. In home theaters, felt ensures a cinema-like sound experience without disturbing reflections.

In the home office, good acoustics are crucial for concentration and video conferences. Acoustic felt on the wall behind the desk absorbs keyboard noise and voices, so you are understood more clearly in online meetings. Also in open-plan offices, strategically placed felt panels improve speech intelligibility and reduce noise levels.

Music and creative rooms

For music rooms, rehearsal rooms, and recording studios, controlled acoustics are essential. Too much echo distorts the sound, too little makes rooms sound dead. Acoustic felt helps find the balance. The combination of wood slats and felt, as with the Wood Acoustic Panels, is ideal: The slats scatter the sound and prevent flutter echoes, while the felt absorbs excess energy.

In gaming rooms and streaming rooms, acoustic felt ensures professional sound quality during recordings. Viewers and listeners perceive the improved speech intelligibility positively, which increases the quality of the content.

Public and commercial spaces

In restaurants, cafés, and hotels, good acoustics contribute significantly to the feel-good factor. Acoustic felt on walls or ceilings reduces the noise level and enables relaxed conversations. In waiting areas, medical practices, and therapy rooms, it creates a calming atmosphere.

Also in educational institutions such as schools and kindergartens, acoustic felt improves learning conditions. Studies show that children are more attentive in rooms with good acoustics and understand teaching content better. The Wall protection panels made of acoustic felt offer a dual benefit here: They protect the walls from damage and simultaneously improve room acoustics.

Special application: Wall protection with acoustic insulation effect

An innovative further development is wall protection panels that combine mechanical protection and soundproofing. These panels are made of highly compressed acoustic felt (1500 g/m², 9 mm thickness) and protect walls from impacts, scratches, and abrasion.

Typical locations are garages (protection against car doors), hallways and stairwells (protection against furniture transport), behind beds and sofas (wall protection), and as dart protection behind dartboards. The panels simultaneously reduce up to 80 percent of the noise generated on impact – such as slamming doors or bumping into objects.

The self-adhesive back enables quick installation without tools. The panels are water-repellent and can be cleaned with a damp cloth. You can find more information in our article on wall protection made of acoustic felt.

Placing felt correctly: Tips for optimal effect

The effect of acoustic felt depends not only on the quantity but also on the placement. Sound waves behave in rooms according to physical laws that you can utilize.

Identifying reflection points

Sound propagates in a straight line and is reflected on smooth surfaces. Particularly problematic are opposing parallel walls that generate flutter echoes. Place acoustic felt on at least one of the parallel walls, ideally offset, to interrupt these reflections.

In rooms with high ceilings, ceiling installations are also sensible. Sound that is reflected upwards contributes significantly to the overall echo level. Self-adhesive felt panels can be easily attached to ceilings and are particularly effective there.

Area calculation and distribution

As a rule of thumb: At least 15 to 20 percent of the wall surface should be covered with absorbent material. For a 20 m² room with a 2.50 m ceiling height (wall area approx. 40 m²), this corresponds to about 6 to 8 m² of acoustic felt.

Distribute the panels as evenly as possible in the room, instead of concentrating everything on one wall. A symmetrical arrangement looks visually harmonious and ensures balanced acoustics. Combinations of different products – such as wood panels as an eye-catcher and felt panels as a supplement – create interesting designs.

Care and longevity of acoustic felt

High-quality acoustic felts are designed for longevity. The special surface sealing makes them water-repellent and colorfast. Dust and light soiling can be removed with a damp cloth or vacuum cleaner (soft brush).

In contrast to foam, which becomes porous and discolored over time, PET felts retain their shape and color for years. They are UV-resistant and do not yellow. The sound absorption also remains constant because the fiber structure does not change.

For heavily used areas such as kindergartens or public spaces, regular cleaning is recommended. The panels are robust enough to withstand frequent wiping without being damaged.

Cost-benefit analysis: Is felt for soundproofing worth it?

Compared to structural measures such as facing shells, drywall construction, or special acoustic ceilings, felt for soundproofing is a cost-effective alternative. Self-adhesive felt panels cost approximately 40 USD per piece, while wood acoustic panels are available starting at 86 USD for a 2-piece set.

For a typical 20 m² room, you need about 6 to 8 m² of acoustic surface, which corresponds to material costs of approximately 260 to 850 USD – depending on the chosen product. Additionally, there may be mounting adhesive or fastening material for about 20 to 50 USD. Professional craftsmanship costs are eliminated since installation can be done independently.

For comparison: A facing shell with drywall and insulation quickly costs 110 to 220 USD per square meter of wall surface including material and installation – for a 20 m² room, that's 4,400 to 8,800 USD. Additionally, several centimeters of room depth are lost. You can learn more about structural alternatives in our article on materials for soundproofing.

The investment in acoustic felt pays off through improved quality of life, higher concentration in the home office, and better sleep quality. In commercial spaces, good acoustics measurably increase customer satisfaction and employee productivity.

Frequently Asked Questions (FAQ)