| 主权项 |
1. An earmuff comprising:
a 30-35 mm mylar film speaker unit; a speaker plate, having a lip and a recessed portion with a base; a reticulated foam ring, having a hollow cavity space with an open volume of air; a reticulated sound attenuating foam material; a non-reticulated moulded foam; and a shell; wherein: the speaker unit comprises a diaphragm, a magnet, and a casing, wherein the casing has an open front and a closed rear, wherein the rear of the casing comprises one or more open apertures, and wherein an air space is formed between the diaphragm and the casing; the speaker plate comprises one or more open holes in the recessed portion; the speaker sits atop the lip of the speaker plate so that the recessed portion of the speaker plate forms a first chamber between the rear of the casing of the speaker and the base of the recessed portion of the speaker plate; the foam ring is located behind the speaker plate and between and in contact with the speaker plate and the sound attenuating foam material, such that the hollow cavity space within the ring forms a second chamber between the base of the recessed portion of the speaker plate and the sound attenuating foam material; the one or more open holes in the recessed portion of the speaker plate open into the hollow cavity space of the foam ring; the speaker unit, speaker plate, foam ring, and sound attenuating foam material are located within the shell of the earmuff; and the non-reticulated moulded foam substantially fills any remaining space within the shell of the earmuff. |
