Question 1

Where does the displayed dB value come from?

Many soundproof curtains display a number in decibels—“-30 dB,” “-28 dB,” “-22 dB.” This number can come from three very different sources:

✓ An accredited independent lab report —the only number that matters. A third-party organization tested the product according to a specific international standard, under controlled and reproducible conditions.

✗ A DIY test —a smartphone placed in a room, a "before and after" video. No normative value. The test conditions, the measured frequency, and the room's layout make any comparison impossible.

✗ A marketing figure —with no source whatsoever. No laboratory named, no standard cited, and no report available. A figure thrown onto a product sheet to inspire confidence.

What you should ask: Which laboratory? Which testing standard? Is there a report number?

Question 2

Is the laboratory accredited and identifiable?

A reputable independent acoustics laboratory is accredited by a recognized national or European body. In Europe, this refers to accreditation by BELAC (Belgium), COFRAC (France), DAkkS (Germany), or an equivalent body, in accordance with ISO 17025.

This accreditation ensures that measurements are reliable, traceable, and comparable across products. Without it, two dB values from two different "tests" cannot be compared.

What you should ask: What is the name of the laboratory? Is it ISO 17025-accredited? Under which standard was the product tested?

Question 3

Is the technology proprietary or generic?

An effective soundproof curtain relies on a specific multilayer design—a combination of materials selected for their combined acoustic and thermal properties. This design may be the result of several years of development.

A European patent means that an official body has examined and recognized the novelty and originality of the technology. While this is not a guarantee of performance in and of itself, it is a strong indication that the manufacturer has invested in a distinctive technical approach—and is protecting it.

A "soundproof" curtain that lacks patented technology and a documented design—and is sold based solely on its weight and thickness—is generally a generic solution.

What you should ask: Is the technology patented? What is the patent number?

Question 4

Is the fire rating M1?

The M1 classification is the French fire-resistance standard required in hotels, restaurants, public-access facilities (ERP), and commercial spaces. A curtain without M1 classification cannot legally be installed in these environments.

For an individual, this classification is not a legal requirement—but it is an indicator of reliability. Manufacturers who have invested in obtaining M1 certification have had their products tested against the most stringent professional standards. Those who have “not yet obtained” it—some state this explicitly—are selling a product that does not meet professional standards.

What you should ask: Is the curtain classified as M1? If not, why not?

Question 5

Does the brand have any real-world professional experience?

A soundproof curtain for home use sold by a brand that has never worked on professional acoustic projects is a bit like buying hiking boots from a brand that has always sold flip-flops.

Our experience in the B2B sector—hotels, restaurants, recording studios, premium office spaces, and institutions—speaks for itself. These clients demand measurable results, on-time delivery, and products that meet standards. They won’t return to a supplier that disappoints them.

An e-commerce brand founded the same year it sold its first soundproof curtain doesn't have that kind of depth.

What you should ask: How long has this brand been working on acoustic projects? Can it provide verifiable professional references?