A novel acoustic metamaterial structure. made up of both resonator and multiple channels. is proposed to insulate low-frequency broadband noises. Three bandgaps with a total width of 658 Hz can be obtained below 900 Hz when the structure appears as a single negative characteristic within specific frequency ranges. https://www.ealisboa.com/great-deal-Pentair-Union-Collar-2-U11-200PS-super-offer/