Loudspeaker assembly for use outdoors

A loudspeaker assembly configured for use in an Acoustic Vehicle Alerting System, the loudspeaker assembly comprising:

• a loudspeaker including a drive unit and a diaphragm, wherein the drive unit is configured to move the diaphragm along a movement axis, wherein the diaphragm has a front face that faces in a forwards direction parallel to the movement axis and a rear face that faces in a rearwards direction parallel to the movement axis, wherein the loudspeaker has a front face that faces in the forwards direction and includes the front face of the diaphragm;
• and
• a grille positioned in front of the front face of the loudspeaker, with a rear face of the grille facing in the rearwards direction toward the front face of the loudspeaker, and with a front face of the grille facing in the forwards direction,
• wherein the grille is configured to permit sound produced by the front face of the diaphragm to pass through the grille when the loudspeaker is in use, and to inhibit the ingress of water incident on the front face of the grille from entering into a space enclosed between the rear face of the grille and the front face of the loudspeaker when the loudspeaker is in use,
• wherein V1/V2≤0.7, wherein V1 is a volume of space (cm3) enclosed between the front face of the loudspeaker when the diaphragm is in its rest position and the rear face of the grille, and V2 is a volume of space (cm3) enclosed between the front face of the loudspeaker when the diaphragm is in its rest position and a plane perpendicular to the movement axis that has a position along the movement axis corresponding to a forwardmost position of the grille on the movement axis, and
• wherein an acoustic transfer function of the loudspeaker is higher than 3 dB for at least some frequencies in the range 1.8kHz-3.6kHz compared with when the grille is not present.