There are two sound transparency measurement diagrams for every type of acoustic cloth available from Akustikstoff.com: 
Diagram 1 shows the measurement in decibels (dB). It indicates how strongly sound is attenuated across different frequency ranges.
Diagram 2 shows the measurement in dBFS (decibels relative to Full Scale). This is a digital reference measurement that represents the acoustic behaviour in relation to the maximum signal level.

Each diagram contains several curves illustrating the effect of fabric tension (stretching):

• without fabric → reference measurement (open transmission)
• fabric at 0% stretch → unstretched condition
• fabric at 3% stretch → typical installation tension
• fabric at 5% stretch → maximum recommended tension

These measurements demonstrate how minimal the influence of the speaker fabric is on sound reproduction. Even at different tension levels, the sound transparency remains virtually unchanged.