Many suppliers like to present impressive graphs, but without knowing how to read them, those graphics say nothing. Sound transparency is a term that many promote, yet only those who know what truly matters can assess fabric reliably. In this article we explain which factors influence acoustic transmission, how to interpret typical measurements, and what really counts when you don’t want appearance to compromise sound.
When you search online for speaker fabrics, you often run into grand promises and plenty of snake oil, just as with any other aspect of speaker technology. Only reliable measurements matter. But which metrics actually count? What do all those numbers and curves really tell you? And which marketing claims are just empty noise?
The fabric must play along
A top‑quality loudspeaker only delivers its full potential when nothing interferes between the diaphragm and your ear. But speakers are frequently covered for aesthetics, protection, or practical reasons. And as soon as whatever material comes between the sound source and the listener (or a microphone, absorber, or diffuser), things get critical. The fabric may attenuate, reflect, or transmit frequencies unevenly. Then sound changes become audible or acoustic elements such as ceiling clouds work improperly.So what does “sound‑transparent” actually mean?
A fabric is considered sound‑transparent when it allows sound waves to pass through with minimal loss or coloration. Sound is a form of energy that must traverse the material. The less resistance encountered, the less energy absorbed or converted into vibration. The result is better sound reproduction. Importantly, this is not subjective: sound transparency can be measured quite precisely.
How is it measured?
A common method is to measure the Sound Pressure Level (SPL in decibels — dB SPL) before and after the fabric. That difference across the frequency band reveals how much the fabric absorbs in particular frequency ranges. A change of about 1 dB is generally considered the threshold between inaudible and noticeable.But SPL is a purely physical measure relating to loudness. Human perception varies depending on frequency and context: two equally loud sounds can seem different in perceived loudness. In psychoacoustics this is referred to as "loudness". So while SPL data provides good guidance, it still requires interpretation.
In digital audio, the unit dBFS (decibels relative to full scale) has become standard. It measures digital audio signal level relative to the maximum possible. Since most transparency tests use digital equipment or sources, dBFS now appears on many measurement protocols and graphs. The logic of interpretation is the same as for dB SPL.
A third essential metric is air permeability, measured in litres of air per second per square metre at 1 bar. Since sound travels in air, high air permeability is always a good indicator of sound transparency. If the fabric significantly resists airflow, it also resists sound.
Why does this matter?
No one wants the direct sound from a speaker to be muffled by the covering fabric or to have the frequency response distorted. For a fabric to be considered sound‑transparent, we expect minimal and as linear as possible reduction of SPL across the frequency range.High frequencies are especially sensitive, as they carry less energy and are more easily absorbed or scattered. A fabric that interferes here deprives the sonic image of clarity and precision. But even bass frequencies can suffer noticeable loss if the fabric is too dense.
What do the numbers say?
On our product pages, under “Properties” → “Acoustic Measurements”, you will find actual test results for every fabric we sell. These demonstrate that well‑designed speaker cloths can be extremely sound‑transparent. Most of our fabrics deliver air‑permeability greatly exceeding 8 000 L/min·m²; frequency response remains nearly linear across the band, with SPL reductions typically well below 1 dB. In practical terms, your speakers will sound just as intended when covered with the fabrics from Akustikstoff.com – whether you’re setting up a HiFi system, a home cinema, or a studio.What to look for when choosing?
Consider these guidelines:Look for actual measurement data, not just marketing claims.
Ideally seek fabrics with minimal SPL loss (only very few dB) and high air permeability.
Appearance can be deceptive: a stylish fabric might seem suitable, but may impact the frequency response.
Avoid fully opaque materials, as they often absorb or reflect much more sound than expected.
Steer clear of heavily textured upholstery fabrics with loose fibres. These absorb or scatter a significant portion of sound in parts of the frequency band. If you want a patterned surface, professional acoustic fabrics printed with designs are a better option.