FAQ - Frequently asked questions

Here you will find answers to the most important questions.

How much absorber material do I need for my room?

As a rule of thumb: For a noticeable improvement in room acoustics, we recommend installing absorber panels/elements whose surface corresponds to approximately 30-50% of the rooms’ floor space.

Our free room acoustics app makes it easy to determine the required quantity.
Link to the App:

Practical tip: The perceived noise level is often subjective. You can of course start with a smaller quantity of acoustic material and later add more if needed.

What thickness should I choose for the various products?

For sound-absorbing materials, the rule is: The thicker the material, the better the effect. For high sound levels or for rooms with very high ceilings (over 3 m), choose the thicker version of the material.

For sound-insulating materials, the rule is: A material of 25 mm thickness is sufficient to attenuate noise events in a wide bandwidth of frequencies. Materials of 50 mm thickness add extra absorption efficiency at lower frequencies.

How do sound absorbers work?

All our acoustic products are made of open-cell materials, which perfectly absorbs sound waves. When absorbed, the sound energy is converted into heat energy. This creates the desired effect of less reverberation or noise being heard in a room.

Will soniflex provide me with a quote?

You are welcome to send a non-binding inquiry describing your “noise problem” to sales@soniflex.de. On this basis we can provide you with an individual offer, and you can go from there.

However, you will receive your goods faster if you order directly at our online shop. Our online shop is open for private and commercial customers alike.

Is it also possible to purchase on account?

For commercial customers, depending on the case, we offer the option of a purchase on account up to a value of 500€. Public institutions are supplied on account. Please contact us for more details.

How long is the delivery time?

Within Germany, the goods are delivered in about 5-10 days. For certain products, other delivery times may apply. These are stated on the respective product page.

More details about payment and delivery can be found here: Payment and delivery

How much are the shipping costs?

Within Germany orders of 100 € or more are delivered free of shipping costs.

For order volumes up to 100 €, a packaging and shipping charge of 19.90 € (VAT incl.) applies.

For shipping costs to other countries, please refer to the following table: Shipping Costs and Minimum Order Value

What is the minimum order value?

The minimum order value (value of goods) is 45.00 €, VAT incl. (= 37.82 €, VAT excl.)

Can I return the goods purchased?

Please note the consequences of a withdrawal from the contract: Right of cancellation.

Please return the goods promptly, at all events not later than within fourteen days after informing us in writing of your decision to withdraw from the contract. Please send the goods to return to:

Cellofoam International GmbH & Co. KG - Business unit soniflex
Abteilung QS
Freiburger Str. 44
88400 Biberach

You shall bear the direct costs of the return shipment. Freight-collect shipments will not be accepted by our receiving department.

After processing your return, we will refund the price paid for the returned goods to the payment method you chose when placing your order (bank transfer, PayPal, credit card or direct debit).

The right of withdrawal does not apply to business customers. It applies only to consumers within the meaning of §13 BGB (German Civil Code). If you have placed your order on behalf of and on account of a company, a return of goods / cancellation of the contract is not possible.

Are the shipments tracked?

When your package leaves our company, we will send you a shipping confirmation email. This message will include also a tracking number.

What is the difference between sound insulation and sound attenuation?

Sound insulation means that a noise shield prevents sound events from passing from one room to another. Examples: the insulation of the wall to the neighbor, or the encapsulation of a noisy machine. The purpose of the measure is to build a "dam" around the sound source to prevent the noise from spreading.

Sound absorption means the weakening of airborne sound levels in a room.
- improved speech intelligibility
- reduced noise volume
- reduced reverberation
- optimized room acoustics

Are the sound absorbers combustible?

Depending on the type of material, our sound absorbers have different temperature resistance levels. For enhanced fire protection, fire-resistant fibers may be integrated in the product. Hence, many of our products are classified as flame-retardant.

How can I install the products?

For many of our products, a self-adhesive backing option is available. Please note that self-adhesive absorber materials cannot be removed again without trace. Exception: For our door insulation solution soni PORTA we use a self-adhesive solution that allows the elements to be removed without residue.

In most cases, our sound insulation panels are fixed on the surface with our soni SPECIAL ADHESIVE .

For further mounting options, please see: Accessories


soni VELCRO tape
Strongly adhesive Velcro tape - for easy and fast installation of acoustic materials made from polyester (PES) non wovens.Our soni VELCRO tape is ideal for fastening acoustic elements such as soni ELEMENT, soni COMFORT, soni CIRCLE or soni HEXAGON.Cut off the Velcro tape to the required length. Remove the protective film from the tape's adhesive side and stick the Velcro tape with the adhesive backing to the wall. Then press the acoustic element on the Velcro tape to fix it. This fixation method allows the acoustic element to be replaced at any time if necessary.Recommended length of the Velcro tape: For a secure hold, cut the Velcro tape to approximately the width of the acoustic element.

Content: 5 m (€4.98* / 1 m)

soni RING HANGER - for easy and fast mounting of acoustic materials. An excellent solution for the installation of sound absorbers such as soni ELEMENT, soni PROTECT or soni COMFORT.After removing the protective film, affix the soni ring hanger at the desired place on the acoustic element and hang the element from a screw hook (not included in the scope of delivery) or similar on the wall or ceiling.Ring hanger, self-adhesive for strong, long-term bondDimensions: 4.5 x 4.5 cm + ringMax. load per ring hanger: max. 1 kg

Our soni SPECIAL ADHESIVE is an ideal adhesive for spot and full-surface fixation of sound-insulation materials and acoustic elements made of open-cell foam, especially melamine and PUR foams. The solvent-free, stable soni SPECIAL ADHESIVE provides excellent adherence to typical building materials, such as concrete, plaster, masonry, cement and wood. With the elastoplastic, single-component polymer adhesive, our open-cell foam panels can be glued directly to the wall or ceiling. Our soni SPECIAL ADHESIVE is available in 310-ml-cartridges, in sets of 6 or 12 cartridges. Please note: soni SPECIAL ADHESIVE is not suitable for PE foams such as soni RESIST. Keep out of reach of children!

Variants from €5.90*
For the mechanical fixation of soundproofing material. Set 1 (for 25 to 32 mm thick material) consists of 20 nylon anchors 8x40, 20 screws 6x70/42 and 20 fixation disks. Set 2 (for 50 to 52 mm thick material) consists of 20 nylon anchors 8x40, 20 screws 6x90/56 and 20 fixation disks.

Variants from €11.50*
soni MOUNTING PINS (20 pieces)
Our soni MOUNTING PINS offer an easy and fast method for the installation of acoustic materials on smooth and clean surfaces.  soni MOUNTING PINS have a base plate with self-adhesive back. The high-quality adhesive ensures secure installation of our acoustic materials for the long term. Use the enclosed fixation disk to hold the noise protection material in place. And, as a last step, cover the tip of the steel pin with the protective cap. The kit consists of 20 base plates with pin, plus fixation disks and protective caps.Kit 1 (pin length: 42 mm) is suitable for noise-control panels of 25 – 30 mm thicknessKit 2 (pin length: 63 mm) is suitable for noise-control panels of 50 mm thickness

soniflex foam suspension spirals (24 pieces)
Acoustic baffles are hung from the ceiling by means of foam-suspension spirals (mind. 50 mm). They are easily inserted into the sheets and can be suspended by means of the eyelets on a wire rope or suspended from hooks.The eyelets can be bent open to serve as hooks. Dimensions: diameter 15 mm, total length 80 mm, length of the coils 69 mm A kit consists of 24 spirals.

Content: 24 piece(s) (€1.04* / 1 piece(s))


Where are soniflex products manufactured?

Our products are "Made in Germany", more specifically they are manufactured at our factories situated halfway between Ulm and Lake Constance in Baden-Württemberg. Despite the fact that we Swabians are known for our thriftiness, we can assure you that we will never skimp on quality when it comes to our products. All our acoustic products are made of high-quality raw materials that ensure high ageing resistance. In addition, our acoustic foams are odorless and durable.

You can find out more about us here here

Does the material decompose over time?

For our acoustic products based on PES fleece, the rated service life is 30 years.

Can I cut the absorbers to the required size and dimensions myself?

Most of our products can be cut to the desired size with a standard cutter knife.

Cutting is easier and more accurate with a jigsaw quipped with a special blade for soft materials (serrated edge), e.g. blades from Bosch or with a special foam saw.

Bosch Schaumstoffsäge mit Sägeblatt

Are the sound absorbers harmful to health?

Our products are made from high-quality raw materials. They are free of mineral fibers and do not present any health hazard.

Which material is suitable for outdoor applications?

If the product will be directly exposed to daylight or UV light, we recommend soni RESIST UV . Thanks to its special UV-stabilizing treatment, soni RESIST UV is perfectly suitable for outdoor applications and offers exceptional weathering resistance.

If the product will be used outdoors but covered/protected by an enclosure, you can also use soni RESIST.

How can I soundproof a compressor or pump?

If you need to sound-proof a compressor or a pump, we recommend building an enclosure at a distance of approx. 30 cm to the device. This distance is required, among other things, because of the heat usually developed by such devices. A 1.5-mm thick steel sheet will provide better insulation values than wood. However, since most users will find it easier to work with wood, we recommend chipboard (thickness: 19 mm or more). Chipboard of this thickness has almost the same effect.

The inside of the enclosure is then lined with acoustic material. We recommend soni COMPOSITE , soni RESIST or soni WAVE . A very convenient alternative is our soni RESIST BOX , which can be set up in just a few minutes.

How can I insulate my roller shutter box?

For sound-insulation purposes, the inside of roller shutter boxes can be lined with a heavy layer, e.g. soni EVA.

Rule of thumb: A doubling of the mass will increase the sound insulation effect by 6 dB. A noise level reduced by 6-10 dB is subjectively perceived to be half as loud. Even more effective is the use of soni COMPOSITE in 32 mm thickness, provided there is sufficient space inside the box.

To dampen the impact when opening or closing the roller shutter, we recommend our roller shutter impact protection soni SOFT-CLOSE.