Acoustic devices and magnetic circuit assemblies thereof

An acoustic device, comprising:

• a shell including a first accommodation cavity;
• a speaker configured in the first accommodation cavity, the speaker including:
• one or more magnetic circuit assemblies, a voice coil, a vibration assembly, and a vibration transmission plate;
• the one or more magnetic circuit assemblies forming a magnetic gap;
• one end of the voice coil being arranged in a magnetic gap, the vibration assembly being connected with the vibration transmission plate, the vibration transmission plate being connected with the shell;
• wherein
• the vibration assembly includes an inner support, an outer support, and a vibration diaphragm;
• another end of the voice coil is connected with the inner support;
• one end of the outer support is physically connected with both sides of the one or more magnetic circuit assemblies;
• the vibration diaphragm is physically connected with the inner support and the outer support to limit a relative movement of the inner support and the outer support in a first direction;
• the first direction being a radial direction of the first accommodation cavity;
• at least one of the inner support, the outer support, or the vibration diaphragm is connected with the vibration transmission plate to transmit vibration to the vibration transmission plate.