08-17-2020, 03:00 PM
(08-17-2020, 11:20 AM)Nard a écrit : Si c'est actif, il doit falloir le brancher sur le secteur
Je viens de lire le lien indiqué par Pascal. Effectivement, ça n'a rien d'actif.
Le AVAA est actif: https://www.psiaudio.swiss/avaa-c20-active-bass-trap/
A microphone will measure the acoustic pressure in front of an acoustic resistance.
The acoustic resistance is designed to let air through but reducing significantly the pressure.
Behind the acoustic resistance, a transducer membrane is driven to absorb the volume of air going through the acoustic resistance as well as ensuring a specific acoustic impedance in front of this acoustic resistance.
When in function, this acoustic impedance in front of the acoustic resistance is significantly lower than in ambient air and therefore acts as a pressure sink.
The acoustic impedance of the air is affected typically over a radius of 1 to 1.5 m around the AVAA. This explains how the AVAA can be more absorbent that its actual surface of perfect absorber.